shader assignment issues with references

[Steve Davy]

Does anyone know a fix for referenced objects which refuse to accept a new shader assignment in a parent scene file?

I've come across this before and the only fix I know of is to import. However I'm trying to avoid that.

Is there any way to force an object to accept a new shader?

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[Yaleh paxton-harding]

I think there was some sort of bug with references/shader assignments for specific renderlayers. Maybe you have a mangled renderlayer and it's messing with your shader assignments? Just a thought.

[Matt Estela]

was thinking something similar; maybe do a quick test of the nuclear option; delete all your SGs, reassign, see what happens.

in other news, the maya station blog is posting some great things of late. i know the general consensus is that mentalray buffers in 2009/2010 aren't worth using, but this post seems to offer some workarounds and speedups:

http://mayastation.typepad.com/maya-station/2010/02/writetocolorbuffer.html

[Nicolas Combecave]

It seems your object is being deformed in the scene it's referenced in?

If it's the case, take a look here:

http://mayastation.typepad.com/maya-station/2009/06/ive-deformed-my-referenced-model-and-i-dont-see-the-updates.html

Nicolas

[Steve Davy]

It is being deformed, but the deformer (in this case a skin cluster) is also being referenced. I'm not clear from that blog whether they're implying this problem only occurs when a deformer is added at referencing level.

In any case, this doesn't really make sense in my case because I have ONE instance of a reference that was refusing to accept a new shader, while there are dozens of other instances of the same object referencing from the same file that will take a new one no problem.

Anyway, yes trashing all my render layers seemed to fix it, but that's not exactly an ideal solution.... Argh.

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Date: Fri, 12 Feb 2010 10:12:03 +0100
Subject: Re: [maya_he3d] shader assignment issues with references
From: zezebub...@gmail.com
To: maya...@googlegroups.com

[Yaleh paxton-harding]

Render layers suck, other than for quick tests. I usually build whole new files for each layer. Not nice, but robust for sure. Have looked at this:

http://www.technolumiere.com/software/renderpassdocs/RenderPass.html

Might be a compiled plugin and if so not sure if that will be for your version of Maya. I looked at it once and liked it, but never had a real chance to use it.

[Steve Davy]

Render layers certainly have their problems. Unfortunately where I work they are necessity and we're not able to break out files into pass or layer scene files for the most part, so we're stuck with them.

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Date: Fri, 12 Feb 2010 15:38:07 -0500

Subject: Re: [maya_he3d] shader assignment issues with references

From: yaleh.paxt...@gmail.com
To: maya...@googlegroups.com

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[stephenkmann]

you should be able to use "connect to next available" to make the connection

-=s

[Yaleh paxton-harding]

In that case you might have to bake the references into the file before getting into shader assignment per render layer. At least for the broken shots anyway. I noticed this problem back in I think 8.5, and so I guess it's still there..

[Matt Estela]

Yaleh, from what I've seen the main problem with render layers is when its connection/attribute override system gets confused, and it starts to corrupt set membership and material overrides.

I took a stab at bolting chapman's pass system on to maya's render layers, so that is all defined through mel layer overrides. Worked well for us. Also makes pass management much more portable, so you could quickly take an existing setup and attach it to a fresh scene. If you only use maya's render layers as a layer naming system (and as a method for managing layer submission to a farm), its fine. Enyhoo:

http://www.tokeru.com/t/bin/view/Maya/MayaRender#Mel_Render_Layer_Overrides_GUI

Got part-way through a converter so that it would analyse an existing gui-based layer setup, and convert it to mel overrides, but never finished it.

Incedentally, I've worked at a few of the bigger studios, from what I've seen they also prefer to roll their own text based methods, much easier to roll out a lighting template to a team of artists.

-matt

[Steve Davy]

Care to elaborate Steve?

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Date: Fri, 12 Feb 2010 15:50:57 -0500

Subject: Re: [maya_he3d] shader assignment issues with references

From: stephe...@gmail.com
To: maya...@googlegroups.com

you should be able to use "connect to next available" to make the connection

-=s

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[stephenkmann]

Sure

I've found that sometimes shaders won't assign to objects for various
reasons. Often involving references that can no longer find their
shaders due to name changes or deleted shader. And when you try to
reassign. Maya errors or does nothing. I've found that I can
sometimes override this behaviour by using the connection editor to
connect shape nodes to shading groups. But using "connect next
available". Rather than just straight connections.

Todo this. Select the shape node and add it to the left side of the
connection editor. And add the shading group to the right.

Find instObjGroups on the shape node and select it(its just past ghosting)

on the right side right mouse button over dagSetMembers[0] and you
will get a menu with "connect next available" as an option.

Try that option.

You don't want to just connect by clicking because if it does work. It
will remove the existing shape node from that slot

Hth

On 2/12/10, Steve Davy <stevi...@hotmail.com> wrote:
>
> Care to elaborate Steve?

>
> Date: Fri, 12 Feb 2010 15:50:57 -0500
> Subject: Re: [maya_he3d] shader assignment issues with references
> From: stephe...@gmail.com
> To: maya...@googlegroups.com
>
> you should be able to use "connect to next available" to make the connection
>
> -=s
>
>
>
>

> _________________________________________________________________

> Hotmail: Powerful Free email with security by Microsoft.

> http://clk.atdmt.com/GBL/go/201469230/direct/01/

--
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-=s

[Steve Davy]

I'm gonna try this next time this happens (won't be long I'm sure!)

Thanks Steve

> Date: Fri, 12 Feb 2010 20:02:53 -0500

[Yaleh paxton-harding]

Hey Matt,
Yeah. Basically as you say, it's necessary to do some more tooling. You really can't just bring in references create renderlayers and then change SGs (easily). It's just not reliable at all. You can use it as a grouping as you could use sets and display layers or whatever I guess, but in a nutshell, it does not work on it's own. Where I'm at we basically have referenced files up to a point then to render we split out large files with no references and no render layers. Each file is a pass (AO, toonlines, BG, whatever, etc..). If a change is needed, we do it to the master referenced file, then re-run a script on the shot to make the new layers. Brute force approach. KISS. The files can get pretty huge, but we can throw them away easily too, since what we care most about is the reference file. The layer files are essentially biproducts from the rendering process.

[Steve Davy]

Part of the problem is just a lack of proper documentation about how to deal with these issues from Autodesk (though to be fair they inherited this shortcoming from Alias). There is really very scant information about a lot of issues and questions that arise when using referencing in production. Shaders and shader assignment is a big one -- despite having used referencing in production a lot over the last couple of years, I'm still unclear what the most stable approach to applying shaders and managing shader updates is. When you throw the broken render layers into the mix as well (as we are more or less obliged to where I work) it becomes a minefield...

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Date: Sun, 14 Feb 2010 11:06:50 -0500

Subject: Re: [maya_he3d] shader assignment issues with references

From: yaleh.paxt...@gmail.com
To: maya...@googlegroups.com

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[Owen]

Hi all,

I'm out of office right now, but when I'm back I'll synthesise this
email thread and pass on the info to our dev/docs teams.

I reckon the quickest thing I can do is post something on the
mayastation blog.

Furthermore, I'll add a category Referencing so that all the stuff
that's related can be easy to find.

Also, if anyone can get away from using render layers, but feels that
render passes only apply to a specific subset of materials, you might
be interested in reading my latest post: writeToColorBuffer,

Thanks for the feedback.

Owen

On Feb 15, 8:22 pm, Steve Davy <stevied...@hotmail.com> wrote:
> Part of the problem is just a lack of proper documentation about how to deal with these issues from Autodesk (though to be fair they inherited this shortcoming from Alias). There is really very scant information about a lot of issues and questions that arise when using referencing in production. Shaders and shader assignment is a big one -- despite having used referencing in production a lot over the last couple of years, I'm still unclear what the most stable approach to applying shaders and managing shader updates is. When you throw the broken render layers into the mix as well (as we are more or less obliged to where I work) it becomes a minefield...
>

> Date: Sun, 14 Feb 2010 11:06:50 -0500
> Subject: Re: [maya_he3d] shader assignment issues with references

> From: yaleh.paxton.hard...@gmail.com

> To: maya...@googlegroups.com
>
> Hey Matt,
> Yeah. Basically as you say, it's necessary to do some more tooling. You really can't just bring in references create renderlayers and then change SGs (easily). It's just not reliable at all. You can use it as a grouping as you could use sets and display layers or whatever I guess, but in a nutshell, it does not work on it's own. Where I'm at we basically have referenced files up to a point then to render we split out large files with no references and no render layers. Each file is a pass (AO, toonlines, BG, whatever, etc..). If a change is needed, we do it to the master referenced file, then re-run a script on the shot to make the new layers. Brute force approach. KISS. The files can get pretty huge, but we can throw them away easily too, since what we care most about is the reference file. The layer files are essentially biproducts from the rendering process.
>

> On Fri, Feb 12, 2010 at 5:12 PM, Matt Estela <m...@tokeru.com> wrote:
>
> Yaleh, from what I've seen the main problem with render layers is when its connection/attribute override system gets confused, and it starts to corrupt set membership and material overrides.
>
> I took a stab at bolting chapman's pass system on to maya's render layers, so that is all defined through mel layer overrides. Worked well for us. Also makes pass management much more portable, so you could quickly take an existing setup and attach it to a fresh scene. If you only use maya's render layers as a layer naming system (and as a method for managing layer submission to a farm), its fine. Enyhoo:
>

> http://www.tokeru.com/t/bin/view/Maya/MayaRender#Mel_Render_Layer_Ove...

>
> Got part-way through a converter so that it would analyse an existing gui-based layer setup, and convert it to mel overrides, but never finished it.
> Incedentally, I've worked at a few of the bigger studios, from what I've seen they also prefer to roll their own text based methods, much easier to roll out a lighting template to a team of artists.
>
> -matt
>

> _________________________________________________________________
> Your E-mail and More On-the-Go. Get Windows Live Hotmail Free.http://clk.atdmt.com/GBL/go/201469229/direct/01/