For my custom renderer, I'm trying to keep track of when materials get
assigned to objects.
This is part of an overall system which tracks changes to the scene so that
I can incrementally process only the parts of the scene that change between
renders.
Since there is no specific event that gets fired when a material is
assigned to an object (that I know of - please correct me if I'm wrong!),
I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command. *By
the way Softimage devs: please add a OnMaterialAssigned event :)*
I have 1 question and 1 issue:
*Question*: Can material assignment happen without this command being run?
In other words, is catching this command sufficient for monitoring all the
ways that a material can be assigned to an object? I'm not very
experienced with using Softimage, but I know that in Maya there are a
million and one ways to assign materials.
*Issue*: While I'm correctly receiving the ApplyMaterial command in the
siOnEndCommand callback, I'm having trouble deciphering the command
arguments.
Basically I want to know the Material that was assigned and the Object(s)
it was assigned to. Simple, right?
In the siOnEndCommand callback, I get the "Command" attribute from the
context and create a Command object from it. I then retreive the arguments
using Command::GetArguments(). The ArgumentArray always has a count of 2
(whether I assign the material to 1 or more objects).
The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to me.
The first argument is a CValueArray that has a CRef for the Material being
assigned as its first element and some mysterious CRef as its second item.
*My issue is that I don't know what to do with this strange CRef*.
Here is a concrete example:
I have 2 objects and 1 material in my scene and assign the material to both
objects in a single action:
Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
"siLetLocalMaterialsOverlap")
In the siOnEndCommand callback I get:
Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns
a CValueArray with 2 items.
Item 0 : CValue, m_t=siRef - this is a CRef to the Material being assigned,
as expected. GetAsText() return "Sources.Materials.DefaultLib.Material"
and GetClassIDName() returns "Material". Good to go.
Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I don't
know how to handle. GetAsText() returns "sphere,cylinder" and
GetClassIDName() returns "Object". What do I do now? How can I get those
objects as CRefs? Do I have to tokenize the string and parse out the
object names? It's not hard, but I'd like to do something cleaner if
possible.
have you tried... siOnCreateShader? i generated this event from the wizard
and it seems to log a lot of relevant info. also there is siOnConnectShader
" *Question*: Can material assignment happen without this command being
run? In other words, is catching this command sufficient for monitoring
all the ways that a material can be assigned to an object? I'm not very
experienced with using Softimage, but I know that in Maya there are a
million and one ways to assign materials. "
-one could change the shader graph but not the material assignment.
-one could 'drag and drop' a material from the material view in the
explorer on to an object. that calls 'CopyPaste()' command. i have always
been on the fence whether that command is good or bad)
On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
> For my custom renderer, I'm trying to keep track of when materials get
> assigned to objects.
> This is part of an overall system which tracks changes to the scene so
> that I can incrementally process only the parts of the scene that change
> between renders.
> Since there is no specific event that gets fired when a material is
> assigned to an object (that I know of - please correct me if I'm wrong!),
> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
> I have 1 question and 1 issue:
> *Question*: Can material assignment happen without this command being
> run? In other words, is catching this command sufficient for monitoring
> all the ways that a material can be assigned to an object? I'm not very
> experienced with using Softimage, but I know that in Maya there are a
> million and one ways to assign materials.
> *Issue*: While I'm correctly receiving the ApplyMaterial command in the
> siOnEndCommand callback, I'm having trouble deciphering the command
> arguments.
> Basically I want to know the Material that was assigned and the Object(s)
> it was assigned to. Simple, right?
> In the siOnEndCommand callback, I get the "Command" attribute from the
> context and create a Command object from it. I then retreive the arguments
> using Command::GetArguments(). The ArgumentArray always has a count of 2
> (whether I assign the material to 1 or more objects).
> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to me.
> The first argument is a CValueArray that has a CRef for the Material being
> assigned as its first element and some mysterious CRef as its second item.
> *My issue is that I don't know what to do with this strange CRef*.
> Here is a concrete example:
> I have 2 objects and 1 material in my scene and assign the material to
> both objects in a single action:
> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
> "siLetLocalMaterialsOverlap")
> In the siOnEndCommand callback I get:
> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
> assigned, as expected. GetAsText() return
> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
> "Material". Good to go.
> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I don't
> know how to handle. GetAsText() returns "sphere,cylinder" and
> GetClassIDName() returns "Object". What do I do now? How can I get those
> objects as CRefs? Do I have to tokenize the string and parse out the
> object names? It's not hard, but I'd like to do something cleaner if
> possible.
I already use siOnConnectShader (and siOnDisconnectShader) to track changes
to the shader tree. These don't get fired as a result of assigning a
material to an object. siOnCreateShader only gets called when you create a
shader node and in fact partially fails at even that since it doesn't get
called when you create a material (which creates a shader as well).
Thanks for the tip on material assignment via drag & drop. Kind of a shame
that it ends up calling CopyPaste command but it should be simple enough to
monitor for that command as well.
On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
> have you tried... siOnCreateShader? i generated this event from the wizard
> and it seems to log a lot of relevant info. also there is siOnConnectShader
> " *Question*: Can material assignment happen without this command being
> run? In other words, is catching this command sufficient for monitoring
> all the ways that a material can be assigned to an object? I'm not very
> experienced with using Softimage, but I know that in Maya there are a
> million and one ways to assign materials. "
> -one could change the shader graph but not the material assignment.
> -one could 'drag and drop' a material from the material view in the
> explorer on to an object. that calls 'CopyPaste()' command. i have always
> been on the fence whether that command is good or bad)
> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>> Hi list people!
>> For my custom renderer, I'm trying to keep track of when materials get
>> assigned to objects.
>> This is part of an overall system which tracks changes to the scene so
>> that I can incrementally process only the parts of the scene that change
>> between renders.
>> Since there is no specific event that gets fired when a material is
>> assigned to an object (that I know of - please correct me if I'm wrong!),
>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
>> I have 1 question and 1 issue:
>> *Question*: Can material assignment happen without this command being
>> run? In other words, is catching this command sufficient for monitoring
>> all the ways that a material can be assigned to an object? I'm not very
>> experienced with using Softimage, but I know that in Maya there are a
>> million and one ways to assign materials.
>> *Issue*: While I'm correctly receiving the ApplyMaterial command in the
>> siOnEndCommand callback, I'm having trouble deciphering the command
>> arguments.
>> Basically I want to know the Material that was assigned and the Object(s)
>> it was assigned to. Simple, right?
>> In the siOnEndCommand callback, I get the "Command" attribute from the
>> context and create a Command object from it. I then retreive the arguments
>> using Command::GetArguments(). The ArgumentArray always has a count of 2
>> (whether I assign the material to 1 or more objects).
>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to
>> me. The first argument is a CValueArray that has a CRef for the Material
>> being assigned as its first element and some mysterious CRef as its second
>> item. *My issue is that I don't know what to do with this strange CRef*.
>> Here is a concrete example:
>> I have 2 objects and 1 material in my scene and assign the material to
>> both objects in a single action:
>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>> "siLetLocalMaterialsOverlap")
>> In the siOnEndCommand callback I get:
>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>> assigned, as expected. GetAsText() return
>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>> "Material". Good to go.
>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I don't
>> know how to handle. GetAsText() returns "sphere,cylinder" and
>> GetClassIDName() returns "Object". What do I do now? How can I get those
>> objects as CRefs? Do I have to tokenize the string and parse out the
>> object names? It's not hard, but I'd like to do something cleaner if
>> possible.
There is unfortunately one last way to assign material to polygons using
the Materials and MaterialID attributes.
And this way is not using a specific command (the user could just set those
values from an ICETree or by script).
It is a relatively new feature, so not too many users know this way though.
Cheers,
Guillaume
On Fri, May 4, 2012 at 8:20 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
> I already use siOnConnectShader (and siOnDisconnectShader) to track
> changes to the shader tree. These don't get fired as a result of assigning
> a material to an object. siOnCreateShader only gets called when you create
> a shader node and in fact partially fails at even that since it doesn't get
> called when you create a material (which creates a shader as well).
> Thanks for the tip on material assignment via drag & drop. Kind of a
> shame that it ends up calling CopyPaste command but it should be simple
> enough to monitor for that command as well.
> -Nicolas
> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>> have you tried... siOnCreateShader? i generated this event from the
>> wizard and it seems to log a lot of relevant info. also there is
>> siOnConnectShader
>> " *Question*: Can material assignment happen without this command being
>> run? In other words, is catching this command sufficient for monitoring
>> all the ways that a material can be assigned to an object? I'm not very
>> experienced with using Softimage, but I know that in Maya there are a
>> million and one ways to assign materials. "
>> -one could change the shader graph but not the material assignment.
>> -one could 'drag and drop' a material from the material view in the
>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>> been on the fence whether that command is good or bad)
>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>>> Hi list people!
>>> For my custom renderer, I'm trying to keep track of when materials get
>>> assigned to objects.
>>> This is part of an overall system which tracks changes to the scene so
>>> that I can incrementally process only the parts of the scene that change
>>> between renders.
>>> Since there is no specific event that gets fired when a material is
>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
>>> I have 1 question and 1 issue:
>>> *Question*: Can material assignment happen without this command being
>>> run? In other words, is catching this command sufficient for monitoring
>>> all the ways that a material can be assigned to an object? I'm not very
>>> experienced with using Softimage, but I know that in Maya there are a
>>> million and one ways to assign materials.
>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in the
>>> siOnEndCommand callback, I'm having trouble deciphering the command
>>> arguments.
>>> Basically I want to know the Material that was assigned and the
>>> Object(s) it was assigned to. Simple, right?
>>> In the siOnEndCommand callback, I get the "Command" attribute from the
>>> context and create a Command object from it. I then retreive the arguments
>>> using Command::GetArguments(). The ArgumentArray always has a count of 2
>>> (whether I assign the material to 1 or more objects).
>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to
>>> me. The first argument is a CValueArray that has a CRef for the Material
>>> being assigned as its first element and some mysterious CRef as its second
>>> item. *My issue is that I don't know what to do with this strange CRef*
>>> .
>>> Here is a concrete example:
>>> I have 2 objects and 1 material in my scene and assign the material to
>>> both objects in a single action:
>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>> "siLetLocalMaterialsOverlap")
>>> In the siOnEndCommand callback I get:
>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>> assigned, as expected. GetAsText() return
>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>> "Material". Good to go.
>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>> object names? It's not hard, but I'd like to do something cleaner if
>>> possible.
I know, this is not answering directly to your issue here, but rethinking
to your problems (tracking FCurves, materials, etc) for the project you're
working, I would ask why not building a custom scene graph (something
relatively simple) where all nodes are just CRef (the encapsulated pointer
to object should stay valid) pointing to SceneObjects. A custom scene graph
would let you implement a faster visitor pattern that you could think of
using the API, which would query the GetEvaluationID and
GetHierarchicalEvaluationID (awesome to avoid to visit an entire branch -
good for perfs) methods to track which scene objects is getting dirty. You
could also register to "siOnObjectAdded" and "siOnObjectRemoved" events to
keep your custom scene graph updated and aware to the scene. The scene
graph would be built when your renderer gets initialized. Im quite sure, it
doesnt fit your needs, but maybe it could help you to get new ideas :)
A node of your scene graph, could be as simple as:
"""
struct scenegraphnode
{
/* next sibling and children as linkedlist */
struct scenegraphnode *siblings[2];
/* previous dirty number */
ulong_t prev_dirty;
/* visitor to query the node */
void (*visit)(struct scenegraphnode *self, struct visitor v);
/* the actual ref */
XSI::CRef ref;
};
"""
Your "struct visitor" could be a struct checking the dirty count, and if it
is not equal to the previous, in charge of getting the new material,
fcurve, position, etc
and sending those new informations to your renderer.
again, just an idea ...
-jo
> I already use siOnConnectShader (and siOnDisconnectShader) to track
> changes to the shader tree. These don't get fired as a result of assigning
> a material to an object. siOnCreateShader only gets called when you create
> a shader node and in fact partially fails at even that since it doesn't get
> called when you create a material (which creates a shader as well).
> Thanks for the tip on material assignment via drag & drop. Kind of a
> shame that it ends up calling CopyPaste command but it should be simple
> enough to monitor for that command as well.
> -Nicolas
> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>> have you tried... siOnCreateShader? i generated this event from the
>> wizard and it seems to log a lot of relevant info. also there is
>> siOnConnectShader
>> " *Question*: Can material assignment happen without this command being
>> run? In other words, is catching this command sufficient for monitoring
>> all the ways that a material can be assigned to an object? I'm not very
>> experienced with using Softimage, but I know that in Maya there are a
>> million and one ways to assign materials. "
>> -one could change the shader graph but not the material assignment.
>> -one could 'drag and drop' a material from the material view in the
>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>> been on the fence whether that command is good or bad)
>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>>> Hi list people!
>>> For my custom renderer, I'm trying to keep track of when materials get
>>> assigned to objects.
>>> This is part of an overall system which tracks changes to the scene so
>>> that I can incrementally process only the parts of the scene that change
>>> between renders.
>>> Since there is no specific event that gets fired when a material is
>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
>>> I have 1 question and 1 issue:
>>> *Question*: Can material assignment happen without this command being
>>> run? In other words, is catching this command sufficient for monitoring
>>> all the ways that a material can be assigned to an object? I'm not very
>>> experienced with using Softimage, but I know that in Maya there are a
>>> million and one ways to assign materials.
>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in the
>>> siOnEndCommand callback, I'm having trouble deciphering the command
>>> arguments.
>>> Basically I want to know the Material that was assigned and the
>>> Object(s) it was assigned to. Simple, right?
>>> In the siOnEndCommand callback, I get the "Command" attribute from the
>>> context and create a Command object from it. I then retreive the arguments
>>> using Command::GetArguments(). The ArgumentArray always has a count of 2
>>> (whether I assign the material to 1 or more objects).
>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to
>>> me. The first argument is a CValueArray that has a CRef for the Material
>>> being assigned as its first element and some mysterious CRef as its second
>>> item. *My issue is that I don't know what to do with this strange CRef*
>>> .
>>> Here is a concrete example:
>>> I have 2 objects and 1 material in my scene and assign the material to
>>> both objects in a single action:
>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>> "siLetLocalMaterialsOverlap")
>>> In the siOnEndCommand callback I get:
>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>> assigned, as expected. GetAsText() return
>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>> "Material". Good to go.
>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>> object names? It's not hard, but I'd like to do something cleaner if
>>> possible.
To Guillaume: Thanks for the heads-up! Do you know of any example scripts
that demonstrate this? I can't seem to assign materials to objects this
way. Also I found 1 more: the ApplyShader command.
To Jo: Well I wasn't even aware of this GetEvaluationID/
GetHierarchicalEvaluationID! I will definitely take a look at this.
Thanks!
On Fri, May 4, 2012 at 5:46 PM, jo benayoun <jobenay...@gmail.com> wrote:
> Hey Nicolas,
> I know, this is not answering directly to your issue here, but rethinking
> to your problems (tracking FCurves, materials, etc) for the project you're
> working, I would ask why not building a custom scene graph (something
> relatively simple) where all nodes are just CRef (the encapsulated pointer
> to object should stay valid) pointing to SceneObjects. A custom scene graph
> would let you implement a faster visitor pattern that you could think of
> using the API, which would query the GetEvaluationID and
> GetHierarchicalEvaluationID (awesome to avoid to visit an entire branch -
> good for perfs) methods to track which scene objects is getting dirty. You
> could also register to "siOnObjectAdded" and "siOnObjectRemoved" events to
> keep your custom scene graph updated and aware to the scene. The scene
> graph would be built when your renderer gets initialized. Im quite sure, it
> doesnt fit your needs, but maybe it could help you to get new ideas :)
> A node of your scene graph, could be as simple as:
> """
> struct scenegraphnode
> {
> /* next sibling and children as linkedlist */
> struct scenegraphnode *siblings[2];
> /* previous dirty number */
> ulong_t prev_dirty;
> /* visitor to query the node */
> void (*visit)(struct scenegraphnode *self, struct visitor v);
> /* the actual ref */
> XSI::CRef ref;
> };
> """
> Your "struct visitor" could be a struct checking the dirty count, and if
> it is not equal to the previous, in charge of getting the new material,
> fcurve, position, etc
> and sending those new informations to your renderer.
> again, just an idea ...
> -jo
> 2012/5/4 Nicolas Burtnyk <nico...@redshift3d.com>
>> Thanks Steven!
>> I already use siOnConnectShader (and siOnDisconnectShader) to track
>> changes to the shader tree. These don't get fired as a result of assigning
>> a material to an object. siOnCreateShader only gets called when you create
>> a shader node and in fact partially fails at even that since it doesn't get
>> called when you create a material (which creates a shader as well).
>> Thanks for the tip on material assignment via drag & drop. Kind of a
>> shame that it ends up calling CopyPaste command but it should be simple
>> enough to monitor for that command as well.
>> -Nicolas
>> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>>> have you tried... siOnCreateShader? i generated this event from the
>>> wizard and it seems to log a lot of relevant info. also there is
>>> siOnConnectShader
>>> " *Question*: Can material assignment happen without this command being
>>> run? In other words, is catching this command sufficient for monitoring
>>> all the ways that a material can be assigned to an object? I'm not very
>>> experienced with using Softimage, but I know that in Maya there are a
>>> million and one ways to assign materials. "
>>> -one could change the shader graph but not the material assignment.
>>> -one could 'drag and drop' a material from the material view in the
>>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>>> been on the fence whether that command is good or bad)
>>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>>>> Hi list people!
>>>> For my custom renderer, I'm trying to keep track of when materials get
>>>> assigned to objects.
>>>> This is part of an overall system which tracks changes to the scene so
>>>> that I can incrementally process only the parts of the scene that change
>>>> between renders.
>>>> Since there is no specific event that gets fired when a material is
>>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>>> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
>>>> I have 1 question and 1 issue:
>>>> *Question*: Can material assignment happen without this command being
>>>> run? In other words, is catching this command sufficient for monitoring
>>>> all the ways that a material can be assigned to an object? I'm not very
>>>> experienced with using Softimage, but I know that in Maya there are a
>>>> million and one ways to assign materials.
>>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in
>>>> the siOnEndCommand callback, I'm having trouble deciphering the command
>>>> arguments.
>>>> Basically I want to know the Material that was assigned and the
>>>> Object(s) it was assigned to. Simple, right?
>>>> In the siOnEndCommand callback, I get the "Command" attribute from the
>>>> context and create a Command object from it. I then retreive the arguments
>>>> using Command::GetArguments(). The ArgumentArray always has a count of 2
>>>> (whether I assign the material to 1 or more objects).
>>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to
>>>> me. The first argument is a CValueArray that has a CRef for the Material
>>>> being assigned as its first element and some mysterious CRef as its second
>>>> item. *My issue is that I don't know what to do with this strange CRef
>>>> *.
>>>> Here is a concrete example:
>>>> I have 2 objects and 1 material in my scene and assign the material to
>>>> both objects in a single action:
>>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>>> "siLetLocalMaterialsOverlap")
>>>> In the siOnEndCommand callback I get:
>>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>>> assigned, as expected. GetAsText() return
>>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>>> "Material". Good to go.
>>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>>> object names? It's not hard, but I'd like to do something cleaner if
>>>> possible.
Actually that seems to be a very excellent idea to me Joe. Again, it
depends on the needs whether to warrant such a structure. But this is very
good way in my view.
I double check before suggesting it, on my side, its aware of material and
animation.
The hierarchical one is pretty awesome, since it avoids you to visit an
entire subtree. so you go pretty quickly to the dirty CRef.
> To Guillaume: Thanks for the heads-up! Do you know of any example
> scripts that demonstrate this? I can't seem to assign materials to objects
> this way. Also I found 1 more: the ApplyShader command.
> To Jo: Well I wasn't even aware of this GetEvaluationID/
> GetHierarchicalEvaluationID! I will definitely take a look at this.
> Thanks!
> On Fri, May 4, 2012 at 5:46 PM, jo benayoun <jobenay...@gmail.com> wrote:
>> Hey Nicolas,
>> I know, this is not answering directly to your issue here, but rethinking
>> to your problems (tracking FCurves, materials, etc) for the project you're
>> working, I would ask why not building a custom scene graph (something
>> relatively simple) where all nodes are just CRef (the encapsulated pointer
>> to object should stay valid) pointing to SceneObjects. A custom scene graph
>> would let you implement a faster visitor pattern that you could think of
>> using the API, which would query the GetEvaluationID and
>> GetHierarchicalEvaluationID (awesome to avoid to visit an entire branch -
>> good for perfs) methods to track which scene objects is getting dirty. You
>> could also register to "siOnObjectAdded" and "siOnObjectRemoved" events to
>> keep your custom scene graph updated and aware to the scene. The scene
>> graph would be built when your renderer gets initialized. Im quite sure, it
>> doesnt fit your needs, but maybe it could help you to get new ideas :)
>> A node of your scene graph, could be as simple as:
>> """
>> struct scenegraphnode
>> {
>> /* next sibling and children as linkedlist */
>> struct scenegraphnode *siblings[2];
>> /* previous dirty number */
>> ulong_t prev_dirty;
>> /* visitor to query the node */
>> void (*visit)(struct scenegraphnode *self, struct visitor v);
>> /* the actual ref */
>> XSI::CRef ref;
>> };
>> """
>> Your "struct visitor" could be a struct checking the dirty count, and if
>> it is not equal to the previous, in charge of getting the new material,
>> fcurve, position, etc
>> and sending those new informations to your renderer.
>> again, just an idea ...
>> -jo
>> 2012/5/4 Nicolas Burtnyk <nico...@redshift3d.com>
>>> Thanks Steven!
>>> I already use siOnConnectShader (and siOnDisconnectShader) to track
>>> changes to the shader tree. These don't get fired as a result of assigning
>>> a material to an object. siOnCreateShader only gets called when you create
>>> a shader node and in fact partially fails at even that since it doesn't get
>>> called when you create a material (which creates a shader as well).
>>> Thanks for the tip on material assignment via drag & drop. Kind of a
>>> shame that it ends up calling CopyPaste command but it should be simple
>>> enough to monitor for that command as well.
>>> -Nicolas
>>> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>>>> have you tried... siOnCreateShader? i generated this event from the
>>>> wizard and it seems to log a lot of relevant info. also there is
>>>> siOnConnectShader
>>>> " *Question*: Can material assignment happen without this command
>>>> being run? In other words, is catching this command sufficient for
>>>> monitoring all the ways that a material can be assigned to an object? I'm
>>>> not very experienced with using Softimage, but I know that in Maya there
>>>> are a million and one ways to assign materials. "
>>>> -one could change the shader graph but not the material assignment.
>>>> -one could 'drag and drop' a material from the material view in the
>>>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>>>> been on the fence whether that command is good or bad)
>>>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com
>>>> > wrote:
>>>>> Hi list people!
>>>>> For my custom renderer, I'm trying to keep track of when materials get
>>>>> assigned to objects.
>>>>> This is part of an overall system which tracks changes to the scene so
>>>>> that I can incrementally process only the parts of the scene that change
>>>>> between renders.
>>>>> Since there is no specific event that gets fired when a material is
>>>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>>>> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
>>>>> I have 1 question and 1 issue:
>>>>> *Question*: Can material assignment happen without this command being
>>>>> run? In other words, is catching this command sufficient for monitoring
>>>>> all the ways that a material can be assigned to an object? I'm not very
>>>>> experienced with using Softimage, but I know that in Maya there are a
>>>>> million and one ways to assign materials.
>>>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in
>>>>> the siOnEndCommand callback, I'm having trouble deciphering the command
>>>>> arguments.
>>>>> Basically I want to know the Material that was assigned and the
>>>>> Object(s) it was assigned to. Simple, right?
>>>>> In the siOnEndCommand callback, I get the "Command" attribute from the
>>>>> context and create a Command object from it. I then retreive the arguments
>>>>> using Command::GetArguments(). The ArgumentArray always has a count of 2
>>>>> (whether I assign the material to 1 or more objects).
>>>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to
>>>>> me. The first argument is a CValueArray that has a CRef for the Material
>>>>> being assigned as its first element and some mysterious CRef as its second
>>>>> item. *My issue is that I don't know what to do with this strange
>>>>> CRef*.
>>>>> Here is a concrete example:
>>>>> I have 2 objects and 1 material in my scene and assign the material to
>>>>> both objects in a single action:
>>>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>>>> "siLetLocalMaterialsOverlap")
>>>>> In the siOnEndCommand callback I get:
>>>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>>>> assigned, as expected. GetAsText() return
>>>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>>>> "Material". Good to go.
>>>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>>>> object names? It's not hard, but I'd like to do something cleaner if
>>>>> possible.
> I already use siOnConnectShader (and siOnDisconnectShader) to track
> changes to the shader tree. These don't get fired as a result of assigning
> a material to an object. siOnCreateShader only gets called when you create
> a shader node and in fact partially fails at even that since it doesn't get
> called when you create a material (which creates a shader as well).
> Thanks for the tip on material assignment via drag & drop. Kind of a
> shame that it ends up calling CopyPaste command but it should be simple
> enough to monitor for that command as well.
> -Nicolas
> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>> have you tried... siOnCreateShader? i generated this event from the
>> wizard and it seems to log a lot of relevant info. also there is
>> siOnConnectShader
>> " *Question*: Can material assignment happen without this command being
>> run? In other words, is catching this command sufficient for monitoring
>> all the ways that a material can be assigned to an object? I'm not very
>> experienced with using Softimage, but I know that in Maya there are a
>> million and one ways to assign materials. "
>> -one could change the shader graph but not the material assignment.
>> -one could 'drag and drop' a material from the material view in the
>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>> been on the fence whether that command is good or bad)
>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>>> Hi list people!
>>> For my custom renderer, I'm trying to keep track of when materials get
>>> assigned to objects.
>>> This is part of an overall system which tracks changes to the scene so
>>> that I can incrementally process only the parts of the scene that change
>>> between renders.
>>> Since there is no specific event that gets fired when a material is
>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
>>> I have 1 question and 1 issue:
>>> *Question*: Can material assignment happen without this command being
>>> run? In other words, is catching this command sufficient for monitoring
>>> all the ways that a material can be assigned to an object? I'm not very
>>> experienced with using Softimage, but I know that in Maya there are a
>>> million and one ways to assign materials.
>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in the
>>> siOnEndCommand callback, I'm having trouble deciphering the command
>>> arguments.
>>> Basically I want to know the Material that was assigned and the
>>> Object(s) it was assigned to. Simple, right?
>>> In the siOnEndCommand callback, I get the "Command" attribute from the
>>> context and create a Command object from it. I then retreive the arguments
>>> using Command::GetArguments(). The ArgumentArray always has a count of 2
>>> (whether I assign the material to 1 or more objects).
>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to
>>> me. The first argument is a CValueArray that has a CRef for the Material
>>> being assigned as its first element and some mysterious CRef as its second
>>> item. *My issue is that I don't know what to do with this strange CRef*
>>> .
>>> Here is a concrete example:
>>> I have 2 objects and 1 material in my scene and assign the material to
>>> both objects in a single action:
>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>> "siLetLocalMaterialsOverlap")
>>> In the siOnEndCommand callback I get:
>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>> assigned, as expected. GetAsText() return
>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>> "Material". Good to go.
>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>> object names? It's not hard, but I'd like to do something cleaner if
>>> possible.
To Steven : if the application of the shader to the object creates a shader
and a material and connects the shader to the material, then yeah, those
events are called. But if you assign an existing material, they're not.
To Jo: I'm playing with this right now and it's very promising. I wonder
though if it's possible to get the same hierarchical evaluation id after
some edits. The reason I'm worried about this is that I noticed that
assigning different materials to an object caused the hierarchical
evaluation id to go up and down. I wonder if some combination of edits
could result in the same evaluation id and therefore cause my system to
think nothing has changed which would obviously be pretty bad! Other than
this worry, and verifying that this is valid for all kinds of edits that
might change the way an object is rendered, this technique of checking the
hierarchical object id might be a lot simpler than chasing down every last
little command, callback, etc.. that can change the scene.
On Fri, May 4, 2012 at 6:02 PM, Steven Caron <car...@gmail.com> wrote:
> in my quick test i applied multiple shader's from the menu, both standard
> and custom. both seemed to get fired. i could have been wrong.
> On Fri, May 4, 2012 at 5:20 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>> Thanks Steven!
>> I already use siOnConnectShader (and siOnDisconnectShader) to track
>> changes to the shader tree. These don't get fired as a result of assigning
>> a material to an object. siOnCreateShader only gets called when you create
>> a shader node and in fact partially fails at even that since it doesn't get
>> called when you create a material (which creates a shader as well).
>> Thanks for the tip on material assignment via drag & drop. Kind of a
>> shame that it ends up calling CopyPaste command but it should be simple
>> enough to monitor for that command as well.
>> -Nicolas
>> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>>> have you tried... siOnCreateShader? i generated this event from the
>>> wizard and it seems to log a lot of relevant info. also there is
>>> siOnConnectShader
>>> " *Question*: Can material assignment happen without this command being
>>> run? In other words, is catching this command sufficient for monitoring
>>> all the ways that a material can be assigned to an object? I'm not very
>>> experienced with using Softimage, but I know that in Maya there are a
>>> million and one ways to assign materials. "
>>> -one could change the shader graph but not the material assignment.
>>> -one could 'drag and drop' a material from the material view in the
>>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>>> been on the fence whether that command is good or bad)
>>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>>>> Hi list people!
>>>> For my custom renderer, I'm trying to keep track of when materials get
>>>> assigned to objects.
>>>> This is part of an overall system which tracks changes to the scene so
>>>> that I can incrementally process only the parts of the scene that change
>>>> between renders.
>>>> Since there is no specific event that gets fired when a material is
>>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>>> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
>>>> I have 1 question and 1 issue:
>>>> *Question*: Can material assignment happen without this command being
>>>> run? In other words, is catching this command sufficient for monitoring
>>>> all the ways that a material can be assigned to an object? I'm not very
>>>> experienced with using Softimage, but I know that in Maya there are a
>>>> million and one ways to assign materials.
>>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in
>>>> the siOnEndCommand callback, I'm having trouble deciphering the command
>>>> arguments.
>>>> Basically I want to know the Material that was assigned and the
>>>> Object(s) it was assigned to. Simple, right?
>>>> In the siOnEndCommand callback, I get the "Command" attribute from the
>>>> context and create a Command object from it. I then retreive the arguments
>>>> using Command::GetArguments(). The ArgumentArray always has a count of 2
>>>> (whether I assign the material to 1 or more objects).
>>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to
>>>> me. The first argument is a CValueArray that has a CRef for the Material
>>>> being assigned as its first element and some mysterious CRef as its second
>>>> item. *My issue is that I don't know what to do with this strange CRef
>>>> *.
>>>> Here is a concrete example:
>>>> I have 2 objects and 1 material in my scene and assign the material to
>>>> both objects in a single action:
>>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>>> "siLetLocalMaterialsOverlap")
>>>> In the siOnEndCommand callback I get:
>>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>>> assigned, as expected. GetAsText() return
>>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>>> "Material". Good to go.
>>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>>> object names? It's not hard, but I'd like to do something cleaner if
>>>> possible.
Unfortunately I was able to pretty easily break this system :(
While playing around with all kinds of edits, I noticed that when I had
Material1 assigned to my object the hierarchical eval id was 20 less than
when I had Material2 assigned. I also noticed that if the object had a
bend modifier on it, changing the bend angle would increment the
hierarchical eval id by 2. So with this sequence of events, I got the same
eval id before and after edits.
*Hierarchical eval id of the sphere is shown in brackets at each step*
Start: sphere with bend modifier, Material2 assigned (226)
Assign material 1 (206)
Change the bend angle 10 times (226)
The problem is the way the hierarchical eval id is computed by simply
summing the eval ids up the hierarchy. Maybe instead, I could crawl the
hierarchy myself (annoying but not a big deal) and compute a hash from all
eval ids in the hierarchy of the object. Assuming a suitable hash
function, any change to any eval id in the hierarchy would cause big
changes in the hash and bring the probability of a false negative down to
some infinitesimally small amount.
On Fri, May 4, 2012 at 6:12 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
> To Steven : if the application of the shader to the object creates a
> shader and a material and connects the shader to the material, then yeah,
> those events are called. But if you assign an existing material, they're
> not.
> To Jo: I'm playing with this right now and it's very promising. I wonder
> though if it's possible to get the same hierarchical evaluation id after
> some edits. The reason I'm worried about this is that I noticed that
> assigning different materials to an object caused the hierarchical
> evaluation id to go up and down. I wonder if some combination of edits
> could result in the same evaluation id and therefore cause my system to
> think nothing has changed which would obviously be pretty bad! Other than
> this worry, and verifying that this is valid for all kinds of edits that
> might change the way an object is rendered, this technique of checking the
> hierarchical object id might be a lot simpler than chasing down every last
> little command, callback, etc.. that can change the scene.
> Thanks guys!!
> On Fri, May 4, 2012 at 6:02 PM, Steven Caron <car...@gmail.com> wrote:
>> in my quick test i applied multiple shader's from the menu, both standard
>> and custom. both seemed to get fired. i could have been wrong.
>> On Fri, May 4, 2012 at 5:20 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>>> Thanks Steven!
>>> I already use siOnConnectShader (and siOnDisconnectShader) to track
>>> changes to the shader tree. These don't get fired as a result of assigning
>>> a material to an object. siOnCreateShader only gets called when you create
>>> a shader node and in fact partially fails at even that since it doesn't get
>>> called when you create a material (which creates a shader as well).
>>> Thanks for the tip on material assignment via drag & drop. Kind of a
>>> shame that it ends up calling CopyPaste command but it should be simple
>>> enough to monitor for that command as well.
>>> -Nicolas
>>> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>>>> have you tried... siOnCreateShader? i generated this event from the
>>>> wizard and it seems to log a lot of relevant info. also there is
>>>> siOnConnectShader
>>>> " *Question*: Can material assignment happen without this command
>>>> being run? In other words, is catching this command sufficient for
>>>> monitoring all the ways that a material can be assigned to an object? I'm
>>>> not very experienced with using Softimage, but I know that in Maya there
>>>> are a million and one ways to assign materials. "
>>>> -one could change the shader graph but not the material assignment.
>>>> -one could 'drag and drop' a material from the material view in the
>>>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>>>> been on the fence whether that command is good or bad)
>>>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com
>>>> > wrote:
>>>>> Hi list people!
>>>>> For my custom renderer, I'm trying to keep track of when materials get
>>>>> assigned to objects.
>>>>> This is part of an overall system which tracks changes to the scene so
>>>>> that I can incrementally process only the parts of the scene that change
>>>>> between renders.
>>>>> Since there is no specific event that gets fired when a material is
>>>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>>>> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
>>>>> I have 1 question and 1 issue:
>>>>> *Question*: Can material assignment happen without this command being
>>>>> run? In other words, is catching this command sufficient for monitoring
>>>>> all the ways that a material can be assigned to an object? I'm not very
>>>>> experienced with using Softimage, but I know that in Maya there are a
>>>>> million and one ways to assign materials.
>>>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in
>>>>> the siOnEndCommand callback, I'm having trouble deciphering the command
>>>>> arguments.
>>>>> Basically I want to know the Material that was assigned and the
>>>>> Object(s) it was assigned to. Simple, right?
>>>>> In the siOnEndCommand callback, I get the "Command" attribute from the
>>>>> context and create a Command object from it. I then retreive the arguments
>>>>> using Command::GetArguments(). The ArgumentArray always has a count of 2
>>>>> (whether I assign the material to 1 or more objects).
>>>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to
>>>>> me. The first argument is a CValueArray that has a CRef for the Material
>>>>> being assigned as its first element and some mysterious CRef as its second
>>>>> item. *My issue is that I don't know what to do with this strange
>>>>> CRef*.
>>>>> Here is a concrete example:
>>>>> I have 2 objects and 1 material in my scene and assign the material to
>>>>> both objects in a single action:
>>>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>>>> "siLetLocalMaterialsOverlap")
>>>>> In the siOnEndCommand callback I get:
>>>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>>>> assigned, as expected. GetAsText() return
>>>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>>>> "Material". Good to go.
>>>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>>>> object names? It's not hard, but I'd like to do something cleaner if
>>>>> possible.
Well, you can still subscribe to an event like "siOnValueChange" or why not
a timer that will helps you to get an idea to when run your visitor thru
your custom scene graph.
It would be enough to make a trace between each user edit. At worst you can
adjust the stepping of your custom timer. Also since you're only storing
the previous ID, that should not be a problem.
Thinking of lexer implementation, why not storing the last two IDs, and be
sure your object is actually changing before firing an update. Im quite
sure actually you will get the opposite issue, that the render event is
fired too often instead of not enough ...
Anyways, there is more to explore and if you go with that way, Im sure new
issues will pop up !
> To Steven : if the application of the shader to the object creates a
> shader and a material and connects the shader to the material, then yeah,
> those events are called. But if you assign an existing material, they're
> not.
> To Jo: I'm playing with this right now and it's very promising. I wonder
> though if it's possible to get the same hierarchical evaluation id after
> some edits. The reason I'm worried about this is that I noticed that
> assigning different materials to an object caused the hierarchical
> evaluation id to go up and down. I wonder if some combination of edits
> could result in the same evaluation id and therefore cause my system to
> think nothing has changed which would obviously be pretty bad! Other than
> this worry, and verifying that this is valid for all kinds of edits that
> might change the way an object is rendered, this technique of checking the
> hierarchical object id might be a lot simpler than chasing down every last
> little command, callback, etc.. that can change the scene.
> Thanks guys!!
> On Fri, May 4, 2012 at 6:02 PM, Steven Caron <car...@gmail.com> wrote:
>> in my quick test i applied multiple shader's from the menu, both standard
>> and custom. both seemed to get fired. i could have been wrong.
>> On Fri, May 4, 2012 at 5:20 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>>> Thanks Steven!
>>> I already use siOnConnectShader (and siOnDisconnectShader) to track
>>> changes to the shader tree. These don't get fired as a result of assigning
>>> a material to an object. siOnCreateShader only gets called when you create
>>> a shader node and in fact partially fails at even that since it doesn't get
>>> called when you create a material (which creates a shader as well).
>>> Thanks for the tip on material assignment via drag & drop. Kind of a
>>> shame that it ends up calling CopyPaste command but it should be simple
>>> enough to monitor for that command as well.
>>> -Nicolas
>>> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>>>> have you tried... siOnCreateShader? i generated this event from the
>>>> wizard and it seems to log a lot of relevant info. also there is
>>>> siOnConnectShader
>>>> " *Question*: Can material assignment happen without this command
>>>> being run? In other words, is catching this command sufficient for
>>>> monitoring all the ways that a material can be assigned to an object? I'm
>>>> not very experienced with using Softimage, but I know that in Maya there
>>>> are a million and one ways to assign materials. "
>>>> -one could change the shader graph but not the material assignment.
>>>> -one could 'drag and drop' a material from the material view in the
>>>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>>>> been on the fence whether that command is good or bad)
>>>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com
>>>> > wrote:
>>>>> Hi list people!
>>>>> For my custom renderer, I'm trying to keep track of when materials get
>>>>> assigned to objects.
>>>>> This is part of an overall system which tracks changes to the scene so
>>>>> that I can incrementally process only the parts of the scene that change
>>>>> between renders.
>>>>> Since there is no specific event that gets fired when a material is
>>>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>>>> *By the way Softimage devs: please add a OnMaterialAssigned event :)*
>>>>> I have 1 question and 1 issue:
>>>>> *Question*: Can material assignment happen without this command being
>>>>> run? In other words, is catching this command sufficient for monitoring
>>>>> all the ways that a material can be assigned to an object? I'm not very
>>>>> experienced with using Softimage, but I know that in Maya there are a
>>>>> million and one ways to assign materials.
>>>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in
>>>>> the siOnEndCommand callback, I'm having trouble deciphering the command
>>>>> arguments.
>>>>> Basically I want to know the Material that was assigned and the
>>>>> Object(s) it was assigned to. Simple, right?
>>>>> In the siOnEndCommand callback, I get the "Command" attribute from the
>>>>> context and create a Command object from it. I then retreive the arguments
>>>>> using Command::GetArguments(). The ArgumentArray always has a count of 2
>>>>> (whether I assign the material to 1 or more objects).
>>>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to
>>>>> me. The first argument is a CValueArray that has a CRef for the Material
>>>>> being assigned as its first element and some mysterious CRef as its second
>>>>> item. *My issue is that I don't know what to do with this strange
>>>>> CRef*.
>>>>> Here is a concrete example:
>>>>> I have 2 objects and 1 material in my scene and assign the material to
>>>>> both objects in a single action:
>>>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>>>> "siLetLocalMaterialsOverlap")
>>>>> In the siOnEndCommand callback I get:
>>>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>>>> assigned, as expected. GetAsText() return
>>>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>>>> "Material". Good to go.
>>>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>>>> object names? It's not hard, but I'd like to do something cleaner if
>>>>> possible.
This depends of the frequency of your scenegraph traversal. For sure, if
you run it like this
Start: sphere with bend modifier, Material2 assigned (226)
traversal
Assign material 1 (206)
Change the bend angle 10 times (226)
traversal
the system will break. But visiting at this frequency will work:
Start: sphere with bend modifier, Material2 assigned (226)
traversal
Assign material 1 (206)
traversal
Change the bend angle 10 times (226)
traversal
Since you can avoid visiting entire branches because of the hierarchical
attribute. I bet a traversal would be really fast to do reducing the number
of visited node (all nodes are not traversed unlike the original visitor
pattern).
The frequency is up to you, with a custom timer, or by subscribing to
"siOnValueChanged" should be enough.
> Unfortunately I was able to pretty easily break this system :(
> While playing around with all kinds of edits, I noticed that when I had
> Material1 assigned to my object the hierarchical eval id was 20 less than
> when I had Material2 assigned. I also noticed that if the object had a
> bend modifier on it, changing the bend angle would increment the
> hierarchical eval id by 2. So with this sequence of events, I got the same
> eval id before and after edits.
> *Hierarchical eval id of the sphere is shown in brackets at each step*
> Start: sphere with bend modifier, Material2 assigned (226)
> Assign material 1 (206)
> Change the bend angle 10 times (226)
> The problem is the way the hierarchical eval id is computed by simply
> summing the eval ids up the hierarchy. Maybe instead, I could crawl the
> hierarchy myself (annoying but not a big deal) and compute a hash from all
> eval ids in the hierarchy of the object. Assuming a suitable hash
> function, any change to any eval id in the hierarchy would cause big
> changes in the hash and bring the probability of a false negative down to
> some infinitesimally small amount.
> On Fri, May 4, 2012 at 6:12 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>> To Steven : if the application of the shader to the object creates a
>> shader and a material and connects the shader to the material, then yeah,
>> those events are called. But if you assign an existing material, they're
>> not.
>> To Jo: I'm playing with this right now and it's very promising. I wonder
>> though if it's possible to get the same hierarchical evaluation id after
>> some edits. The reason I'm worried about this is that I noticed that
>> assigning different materials to an object caused the hierarchical
>> evaluation id to go up and down. I wonder if some combination of edits
>> could result in the same evaluation id and therefore cause my system to
>> think nothing has changed which would obviously be pretty bad! Other than
>> this worry, and verifying that this is valid for all kinds of edits that
>> might change the way an object is rendered, this technique of checking the
>> hierarchical object id might be a lot simpler than chasing down every last
>> little command, callback, etc.. that can change the scene.
>> Thanks guys!!
>> On Fri, May 4, 2012 at 6:02 PM, Steven Caron <car...@gmail.com> wrote:
>>> in my quick test i applied multiple shader's from the menu, both
>>> standard and custom. both seemed to get fired. i could have been wrong.
>>> On Fri, May 4, 2012 at 5:20 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>>>> Thanks Steven!
>>>> I already use siOnConnectShader (and siOnDisconnectShader) to track
>>>> changes to the shader tree. These don't get fired as a result of assigning
>>>> a material to an object. siOnCreateShader only gets called when you create
>>>> a shader node and in fact partially fails at even that since it doesn't get
>>>> called when you create a material (which creates a shader as well).
>>>> Thanks for the tip on material assignment via drag & drop. Kind of a
>>>> shame that it ends up calling CopyPaste command but it should be simple
>>>> enough to monitor for that command as well.
>>>> -Nicolas
>>>> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>>>>> have you tried... siOnCreateShader? i generated this event from the
>>>>> wizard and it seems to log a lot of relevant info. also there is
>>>>> siOnConnectShader
>>>>> " *Question*: Can material assignment happen without this command
>>>>> being run? In other words, is catching this command sufficient for
>>>>> monitoring all the ways that a material can be assigned to an object? I'm
>>>>> not very experienced with using Softimage, but I know that in Maya there
>>>>> are a million and one ways to assign materials. "
>>>>> -one could change the shader graph but not the material assignment.
>>>>> -one could 'drag and drop' a material from the material view in the
>>>>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>>>>> been on the fence whether that command is good or bad)
>>>>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <
>>>>> nico...@redshift3d.com> wrote:
>>>>>> Hi list people!
>>>>>> For my custom renderer, I'm trying to keep track of when materials
>>>>>> get assigned to objects.
>>>>>> This is part of an overall system which tracks changes to the scene
>>>>>> so that I can incrementally process only the parts of the scene that change
>>>>>> between renders.
>>>>>> Since there is no specific event that gets fired when a material is
>>>>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>>>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>>>>> *By the way Softimage devs: please add a OnMaterialAssigned event :)
>>>>>> *
>>>>>> I have 1 question and 1 issue:
>>>>>> *Question*: Can material assignment happen without this command
>>>>>> being run? In other words, is catching this command sufficient for
>>>>>> monitoring all the ways that a material can be assigned to an object? I'm
>>>>>> not very experienced with using Softimage, but I know that in Maya there
>>>>>> are a million and one ways to assign materials.
>>>>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in
>>>>>> the siOnEndCommand callback, I'm having trouble deciphering the command
>>>>>> arguments.
>>>>>> Basically I want to know the Material that was assigned and the
>>>>>> Object(s) it was assigned to. Simple, right?
>>>>>> In the siOnEndCommand callback, I get the "Command" attribute from
>>>>>> the context and create a Command object from it. I then retreive the
>>>>>> arguments using Command::GetArguments(). The ArgumentArray always has a
>>>>>> count of 2 (whether I assign the material to 1 or more objects).
>>>>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant
>>>>>> to me. The first argument is a CValueArray that has a CRef for the
>>>>>> Material being assigned as its first element and some mysterious CRef as
>>>>>> its second item. *My issue is that I don't know what to do with
>>>>>> this strange CRef*.
>>>>>> Here is a concrete example:
>>>>>> I have 2 objects and 1 material in my scene and assign the material
>>>>>> to both objects in a single action:
>>>>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>>>>> "siLetLocalMaterialsOverlap")
>>>>>> In the siOnEndCommand callback I get:
>>>>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>>>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>>>>> assigned, as expected. GetAsText() return
>>>>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>>>>> "Material". Good to go.
>>>>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>>>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>>>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>>>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>>>>> object names? It's not hard, but I'd like to do something cleaner if
>>>>>> possible.
Just to be clear, I'm not looking for ways to know when I should re-render.
That's up to the user. What I want is a robust way to know *what* I need
to reprocess (extract geo, convert materials, blah blah) since the last
render.
So, I don't see why I would do any traversal or visiting of nodes on
regular intervals. I would just do this at the start of each render.
Of course with what you're suggesting, the odds are much lower of getting
false negatives since your evaluating "dirtiness" way more often.
On Fri, May 4, 2012 at 6:34 PM, jo benayoun <jobenay...@gmail.com> wrote:
> Hey Nicolas,
> This depends of the frequency of your scenegraph traversal. For sure, if
> you run it like this
> Start: sphere with bend modifier, Material2 assigned (226)
> traversal
> Assign material 1 (206)
> Change the bend angle 10 times (226)
> traversal
> the system will break. But visiting at this frequency will work:
> Start: sphere with bend modifier, Material2 assigned (226)
> traversal
> Assign material 1 (206)
> traversal
> Change the bend angle 10 times (226)
> traversal
> Since you can avoid visiting entire branches because of the hierarchical
> attribute. I bet a traversal would be really fast to do reducing the number
> of visited node (all nodes are not traversed unlike the original visitor
> pattern).
> The frequency is up to you, with a custom timer, or by subscribing to
> "siOnValueChanged" should be enough.
> -jo
> 2012/5/4 Nicolas Burtnyk <nico...@redshift3d.com>
>> Unfortunately I was able to pretty easily break this system :(
>> While playing around with all kinds of edits, I noticed that when I had
>> Material1 assigned to my object the hierarchical eval id was 20 less than
>> when I had Material2 assigned. I also noticed that if the object had a
>> bend modifier on it, changing the bend angle would increment the
>> hierarchical eval id by 2. So with this sequence of events, I got the same
>> eval id before and after edits.
>> *Hierarchical eval id of the sphere is shown in brackets at each step*
>> Start: sphere with bend modifier, Material2 assigned (226)
>> Assign material 1 (206)
>> Change the bend angle 10 times (226)
>> The problem is the way the hierarchical eval id is computed by simply
>> summing the eval ids up the hierarchy. Maybe instead, I could crawl the
>> hierarchy myself (annoying but not a big deal) and compute a hash from all
>> eval ids in the hierarchy of the object. Assuming a suitable hash
>> function, any change to any eval id in the hierarchy would cause big
>> changes in the hash and bring the probability of a false negative down to
>> some infinitesimally small amount.
>> On Fri, May 4, 2012 at 6:12 PM, Nicolas Burtnyk <nico...@redshift3d.com>wrote:
>>> To Steven : if the application of the shader to the object creates a
>>> shader and a material and connects the shader to the material, then yeah,
>>> those events are called. But if you assign an existing material, they're
>>> not.
>>> To Jo: I'm playing with this right now and it's very promising. I
>>> wonder though if it's possible to get the same hierarchical evaluation id
>>> after some edits. The reason I'm worried about this is that I noticed that
>>> assigning different materials to an object caused the hierarchical
>>> evaluation id to go up and down. I wonder if some combination of edits
>>> could result in the same evaluation id and therefore cause my system to
>>> think nothing has changed which would obviously be pretty bad! Other than
>>> this worry, and verifying that this is valid for all kinds of edits that
>>> might change the way an object is rendered, this technique of checking the
>>> hierarchical object id might be a lot simpler than chasing down every last
>>> little command, callback, etc.. that can change the scene.
>>> Thanks guys!!
>>> On Fri, May 4, 2012 at 6:02 PM, Steven Caron <car...@gmail.com> wrote:
>>>> in my quick test i applied multiple shader's from the menu, both
>>>> standard and custom. both seemed to get fired. i could have been wrong.
>>>> On Fri, May 4, 2012 at 5:20 PM, Nicolas Burtnyk <nico...@redshift3d.com
>>>> > wrote:
>>>>> Thanks Steven!
>>>>> I already use siOnConnectShader (and siOnDisconnectShader) to track
>>>>> changes to the shader tree. These don't get fired as a result of assigning
>>>>> a material to an object. siOnCreateShader only gets called when you create
>>>>> a shader node and in fact partially fails at even that since it doesn't get
>>>>> called when you create a material (which creates a shader as well).
>>>>> Thanks for the tip on material assignment via drag & drop. Kind of a
>>>>> shame that it ends up calling CopyPaste command but it should be simple
>>>>> enough to monitor for that command as well.
>>>>> -Nicolas
>>>>> On Fri, May 4, 2012 at 4:54 PM, Steven Caron <car...@gmail.com> wrote:
>>>>>> have you tried... siOnCreateShader? i generated this event from the
>>>>>> wizard and it seems to log a lot of relevant info. also there is
>>>>>> siOnConnectShader
>>>>>> " *Question*: Can material assignment happen without this command
>>>>>> being run? In other words, is catching this command sufficient for
>>>>>> monitoring all the ways that a material can be assigned to an object? I'm
>>>>>> not very experienced with using Softimage, but I know that in Maya there
>>>>>> are a million and one ways to assign materials. "
>>>>>> -one could change the shader graph but not the material assignment.
>>>>>> -one could 'drag and drop' a material from the material view in the
>>>>>> explorer on to an object. that calls 'CopyPaste()' command. i have always
>>>>>> been on the fence whether that command is good or bad)
>>>>>> On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <
>>>>>> nico...@redshift3d.com> wrote:
>>>>>>> Hi list people!
>>>>>>> For my custom renderer, I'm trying to keep track of when materials
>>>>>>> get assigned to objects.
>>>>>>> This is part of an overall system which tracks changes to the scene
>>>>>>> so that I can incrementally process only the parts of the scene that change
>>>>>>> between renders.
>>>>>>> Since there is no specific event that gets fired when a material is
>>>>>>> assigned to an object (that I know of - please correct me if I'm wrong!),
>>>>>>> I'm trying to use *siOnEndCommand *to catch the *AssignMaterial *command.
>>>>>>> *By the way Softimage devs: please add a OnMaterialAssigned event
>>>>>>> :)*
>>>>>>> I have 1 question and 1 issue:
>>>>>>> *Question*: Can material assignment happen without this command
>>>>>>> being run? In other words, is catching this command sufficient for
>>>>>>> monitoring all the ways that a material can be assigned to an object? I'm
>>>>>>> not very experienced with using Softimage, but I know that in Maya there
>>>>>>> are a million and one ways to assign materials.
>>>>>>> *Issue*: While I'm correctly receiving the ApplyMaterial command in
>>>>>>> the siOnEndCommand callback, I'm having trouble deciphering the command
>>>>>>> arguments.
>>>>>>> Basically I want to know the Material that was assigned and the
>>>>>>> Object(s) it was assigned to. Simple, right?
>>>>>>> In the siOnEndCommand callback, I get the "Command" attribute from
>>>>>>> the context and create a Command object from it. I then retreive the
>>>>>>> arguments using Command::GetArguments(). The ArgumentArray always has a
>>>>>>> count of 2 (whether I assign the material to 1 or more objects).
>>>>>>> The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant
>>>>>>> to me. The first argument is a CValueArray that has a CRef for the
>>>>>>> Material being assigned as its first element and some mysterious CRef as
>>>>>>> its second item. *My issue is that I don't know what to do with
>>>>>>> this strange CRef*.
>>>>>>> Here is a concrete example:
>>>>>>> I have 2 objects and 1 material in my scene and assign the material
>>>>>>> to both objects in a single action:
>>>>>>> Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder",
>>>>>>> "siLetLocalMaterialsOverlap")
>>>>>>> In the siOnEndCommand callback I get:
>>>>>>> Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue()returns a CValueArray with 2 items.
>>>>>>> Item 0 : CValue, m_t=siRef - this is a CRef to the Material being
>>>>>>> assigned, as expected. GetAsText() return
>>>>>>> "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns
>>>>>>> "Material". Good to go.
>>>>>>> Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I
>>>>>>> don't know how to handle. GetAsText() returns "sphere,cylinder" and
>>>>>>> GetClassIDName() returns "Object". What do I do now? How can I get those
>>>>>>> objects as CRefs? Do I have to tokenize the string and parse out the
>>>>>>> object names? It's not hard, but I'd like to do something cleaner if
>>>>>>> possible.
If I understand what you are saying, for each "dirty" of your interest, you
would like to capture and store that as soon as it happens and compare it
with last render event to process the delta change. And right now you the
challenge that you are faced with is capturing the "dirties", specially
with the material assignment.
But isn't it true that Joe's proposal lets you visit the scene graph to
capture the scene graph changes at each render, still doing the same thing
but with a different approach.
>> -one could 'drag and drop' a material from the material view in the explorer
>> on to an object. that calls 'CopyPaste()' command. i have always been on
>> the fence whether that command is good or bad)
It is bad ;-)
Not the case anymore, but years ago it was a source of many gremlins and corruptions. Nowadays it's just a nuisance in that you don't get very useful information from the SDK as to what has just happened. For example, if you import geometry from a custom file format, CopyPaste() is called instead of ActiveSceneRoot.AddGeometry() leaving you without much of a hook to determine whether it succeeded or not.
Matt
From: softimage-boun...@listproc.autodesk.com [mailto:softimage-boun...@listproc.autodesk.com] On Behalf Of Steven Caron
Sent: Friday, May 04, 2012 4:55 PM
To: softim...@listproc.autodesk.com
Subject: Re: Getting the objects to which a material was assigned in siOnEndCommand
have you tried... siOnCreateShader? i generated this event from the wizard and it seems to log a lot of relevant info. also there is siOnConnectShader
" Question: Can material assignment happen without this command being run? In other words, is catching this command sufficient for monitoring all the ways that a material can be assigned to an object? I'm not very experienced with using Softimage, but I know that in Maya there are a million and one ways to assign materials. "
-one could change the shader graph but not the material assignment.
-one could 'drag and drop' a material from the material view in the explorer on to an object. that calls 'CopyPaste()' command. i have always been on the fence whether that command is good or bad)
On Fri, May 4, 2012 at 4:39 PM, Nicolas Burtnyk <nico...@redshift3d.com<mailto:nico...@redshift3d.com>> wrote:
Hi list people!
For my custom renderer, I'm trying to keep track of when materials get assigned to objects.
This is part of an overall system which tracks changes to the scene so that I can incrementally process only the parts of the scene that change between renders.
Since there is no specific event that gets fired when a material is assigned to an object (that I know of - please correct me if I'm wrong!), I'm trying to use siOnEndCommand to catch the AssignMaterial command. By the way Softimage devs: please add a OnMaterialAssigned event :)
I have 1 question and 1 issue:
Question: Can material assignment happen without this command being run? In other words, is catching this command sufficient for monitoring all the ways that a material can be assigned to an object? I'm not very experienced with using Softimage, but I know that in Maya there are a million and one ways to assign materials.
Issue: While I'm correctly receiving the ApplyMaterial command in the siOnEndCommand callback, I'm having trouble deciphering the command arguments.
Basically I want to know the Material that was assigned and the Object(s) it was assigned to. Simple, right?
In the siOnEndCommand callback, I get the "Command" attribute from the context and create a Command object from it. I then retreive the arguments using Command::GetArguments(). The ArgumentArray always has a count of 2 (whether I assign the material to 1 or more objects).
The second argument (ActionWhenLocalMaterialsOverlap) is irrelevant to me. The first argument is a CValueArray that has a CRef for the Material being assigned as its first element and some mysterious CRef as its second item. My issue is that I don't know what to do with this strange CRef.
Here is a concrete example:
I have 2 objects and 1 material in my scene and assign the material to both objects in a single action:
Application.AssignMaterial("Sources.Materials.DefaultLib.Material,sphere,cy linder", "siLetLocalMaterialsOverlap")
In the siOnEndCommand callback I get:
Command(Context(in_ctxt).GetAttribute(L"Command")).GetArguments()[0].GetVal ue() returns a CValueArray with 2 items.
Item 0 : CValue, m_t=siRef - this is a CRef to the Material being assigned, as expected. GetAsText() return "Sources.Materials.DefaultLib.Material" and GetClassIDName() returns "Material". Good to go.
Item 1 : CValue, m_t=siRef - this is some kind of weird CRef that I don't know how to handle. GetAsText() returns "sphere,cylinder" and GetClassIDName() returns "Object". What do I do now? How can I get those objects as CRefs? Do I have to tokenize the string and parse out the object names? It's not hard, but I'd like to do something cleaner if possible.
I think there is a misunderstanding on what I'm suggesting and what you
could expect.
1/ When I was talking about increasing the frequency of the custom scene
graph traversal, I was thinking to it in the context of a "quick preview"
ala render region where things have to be updated when a slider is touched.
subscribing to the "siOnValueChanged" or with a custom timer fit the case.
2/ A regular scene graph traversing would happen in the context of your
render is launched but with a range of frames (let say 0-100) where you
dont need to take care of "user edits". It means, that the user press
starts, your scene graph gets initialized and scene graph traversing is
done for every frame. ID is ideal to track animated objects, ...
3/ The other and last one Im thinking about is if the user ask the renderer
for one frame and press the button start, no need of a custom scene graph.
You have to evaluate everything.
In this three cases, I don't see which one would make the system breaks
considering the ID increased or decreased between updates.
If there is a context or something I didn't think about, please, let me
know, that I could try to think to something else ! :)
> If I understand what you are saying, for each "dirty" of your interest,
> you would like to capture and store that as soon as it happens and compare
> it with last render event to process the delta change. And right now you
> the challenge that you are faced with is capturing the "dirties", specially
> with the material assignment.
> But isn't it true that Joe's proposal lets you visit the scene graph to
> capture the scene graph changes at each render, still doing the same thing
> but with a different approach.
XSI already takes care of telling my renderer when we need to render. That
includes preview renders, region renders and "batch" renders for animation.
These all happen using the same mechanism - by calling the custom renderer
"Process" callback.
Since all these types of rendering are handled by a single unified system,
I'm designing my "dirty" system to be more or less agnostic to the type of
rendering that's being performed. I want to avoid having to distinuish
between preview renders, animation renders, region renders etc... For
example, there's no reason to assume everything is dirty for a preview
render (case #3 above). Basically, every time I'm told to render a frame,
I need to determine what's been added, what's been removed and what has
changed since the last render. Also, I need to distinguish between
different kinds of edits - e.g. a change in a mesh's xform only doesn't
require me to re-extract the geometry data from XSI.
To do this, I simply keep track of what (meshes, materials, etc...) I
rendered last time. Let's call this the previous render list. When it's
time to render, I first mark everything in my previous render list as
"unused". I then traverse the XSI scene to collect things to render. For
each "thing" I check whether it's already in my previous render list. If
not, it's a new "thing" and it gets marked for full processing. If it is
found, I mark the "thing" as "used", then determine what kind of processing
it needs (full processing, xform only change, etc...). After everything
has been collected, I go through my render list and anything still marked
as "unused" is removed.
The "determine what kind of processing it needs" stage above is what needs
to check for dirty information. Currently I'm relying on a bunch of
callbacks to maintain a data structure that I can quickly query to see if a
particular object has been dirtied. I am investigating the possibility
of replacing all those callbacks with some checking of the evaluation ids
or hierarchical evaluation ids. This would happen only during the step
when I'm querying the dirty information, not on some regular interval
outside the context of rendering.
Thanks again for suggesting the evaluation id stuff. It looks like that
going to simplify my checks a lot and make the system more robust. It's
absolutely essential for the system to not miss anything - a false negative
will mean we're rendering data that's inconsistent with the current state
of the XSI scene which will lead to a lot of head scratching and
frustration. I'll likely need to accept some false positives in exchange
for never having false negatives - a compromise that is completely
acceptable in this context.
On Fri, May 4, 2012 at 7:12 PM, jo benayoun <jobenay...@gmail.com> wrote:
> Hey Nicolas,
> I think there is a misunderstanding on what I'm suggesting and what you
> could expect.
> 1/ When I was talking about increasing the frequency of the custom scene
> graph traversal, I was thinking to it in the context of a "quick preview"
> ala render region where things have to be updated when a slider is touched.
> subscribing to the "siOnValueChanged" or with a custom timer fit the case.
> 2/ A regular scene graph traversing would happen in the context of your
> render is launched but with a range of frames (let say 0-100) where you
> dont need to take care of "user edits". It means, that the user press
> starts, your scene graph gets initialized and scene graph traversing is
> done for every frame. ID is ideal to track animated objects, ...
> 3/ The other and last one Im thinking about is if the user ask the
> renderer for one frame and press the button start, no need of a custom
> scene graph. You have to evaluate everything.
> In this three cases, I don't see which one would make the system breaks
> considering the ID increased or decreased between updates.
> If there is a context or something I didn't think about, please, let me
> know, that I could try to think to something else ! :)
>> If I understand what you are saying, for each "dirty" of your interest,
>> you would like to capture and store that as soon as it happens and compare
>> it with last render event to process the delta change. And right now you
>> the challenge that you are faced with is capturing the "dirties", specially
>> with the material assignment.
>> But isn't it true that Joe's proposal lets you visit the scene graph to
>> capture the scene graph changes at each render, still doing the same thing
>> but with a different approach.
> It's absolutely essential for the system to not miss anything - a false
> negative will mean we're rendering data that's inconsistent with the
> current state of the XSI scene which will lead to a lot of head scratching
> and frustration. I'll likely need to accept some false positives in
> exchange for never having false negatives - a compromise that is completely
> acceptable in this context.
