"Simulate Bullet Rigid Bodies" evaluates even when condition is False?!

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Alan Fregtman

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Jul 10, 2012, 1:54:32 PM7/10/12
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Hey guys,

It would appear that even when I have an If node presumably preventing executation of "Simulate Bullet Rigid Bodies", it STILL EVALUATES. :o

Ever seen this happen? I'm trying to disable it when I don't need it. I even tried setting particles as passive RBDs but they still react and stuff. I need them to stay still until a given frame.

Everything else in my If node respects the condition, except the sim rbds node. :(

Any help appreciated.
Cheers,

   -- Alan

Stephen Blair

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Jul 10, 2012, 2:38:27 PM7/10/12
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How about muting the Simulate Bullet Rigid Bodies based on the condition you were feeding into the If?

And yes, I got the same thing with an If node.
I event tried plugging in a second, muted Simulate Bullet Rigid Bodies node into the False port
winmail.dat

Alan Fregtman

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Jul 10, 2012, 2:42:36 PM7/10/12
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Tried that already and it's still doing something to my particles. Evil node!! :/

Jonah Friedman

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Jul 10, 2012, 3:38:34 PM7/10/12
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Also, you can't iterate on it and after it runs, it doesn't seem to set attributes like "pointPosition" or "orientation" in any normal way. I'm not a fan of the node either. 

Alan Fregtman

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Jul 10, 2012, 3:45:35 PM7/10/12
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For my need I went back to the... *shivers*... "classic" ICE RBDs, the ones which use bounding boxes.

They act reliably (sans exact collisions) and the node respects conditional confinements.


Sure is a nice "feature" how it evaluates different every time I run the sim though! ...Thanks RBDs!...

Grahame Fuller

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Jul 10, 2012, 3:53:04 PM7/10/12
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I couldn't repro your results in my quick tests. I got a few rogue particles moving when using If - a couple might have been self-collisions but others were puzzling. Mute was more reliable.

IsPassiveRigidBody also worked well. Did you remember to set their PointVelocity and AngularVelocity to zero? Passive RBDs don't react to forces but they do update based on velocity.

gray

From: softimag...@listproc.autodesk.com [mailto:softimag...@listproc.autodesk.com] On Behalf Of Alan Fregtman
Sent: Tuesday, July 10, 2012 03:46 PM
To: soft...@listproc.autodesk.com
Subject: Re: "Simulate Bullet Rigid Bodies" evaluates even when condition is False?!

For my need I went back to the... *shivers*... "classic" ICE RBDs, the ones which use bounding boxes.

They act reliably (sans exact collisions) and the node respects conditional confinements.


Sure is a nice "feature" how it evaluates different every time I run the sim though! ...Thanks RBDs!...

On Tue, Jul 10, 2012 at 3:38 PM, Jonah Friedman <jon...@gmail.com<mailto:jon...@gmail.com>> wrote:
Also, you can't iterate on it and after it runs, it doesn't seem to set attributes like "pointPosition" or "orientation" in any normal way. I'm not a fan of the node either.

On Tue, Jul 10, 2012 at 2:42 PM, Alan Fregtman <alan.f...@gmail.com<mailto:alan.f...@gmail.com>> wrote:
Tried that already and it's still doing something to my particles. Evil node!! :/

On Tue, Jul 10, 2012 at 2:38 PM, Stephen Blair <Stephe...@autodesk.com<mailto:Stephe...@autodesk.com>> wrote:
How about muting the Simulate Bullet Rigid Bodies based on the condition you were feeding into the If?

And yes, I got the same thing with an If node.
I event tried plugging in a second, muted Simulate Bullet Rigid Bodies node into the False port

winmail.dat

Gustavo Eggert Boehs

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Jul 10, 2012, 3:57:39 PM7/10/12
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Workaround... cant you use States for what you are after?
You could use a Simple State (which has a simulate port)

2012/7/10 Grahame Fuller <Grahame...@autodesk.com>



--
Gustavo E Boehs
3d Artist
http://www.gustavoeb.com.br/blog

Grahame Fuller

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Jul 10, 2012, 4:07:39 PM7/10/12
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I got the same result with Simple State as with If: a couple of rogue particles. Not surprising because Simple State uses If internally.

Another thing you could try if IsPassiveRigidBody doesn't work for you:

- Use a custom attribute to keep track of whether each particle should be affected by the Bullet node (Boolean, or integer if you want more than one "state").
- Before the Bullet node, store all relevant attributes (PointPosition, PointVelocity, Force, Mass, Orientation, AngularVelocity, etc.) as custom attributes. Set velocities and force to zero and Mass really really high.
- Let Bullet do its thing.
- After the Bullet node, restore the attributes based on based on your condition, and if desired simulate or move those particles using your own logic.

gray

From: softimag...@listproc.autodesk.com [mailto:softimag...@listproc.autodesk.com] On Behalf Of Gustavo Eggert Boehs
Sent: Tuesday, July 10, 2012 03:58 PM
To: soft...@listproc.autodesk.com
Subject: Re: "Simulate Bullet Rigid Bodies" evaluates even when condition is False?!

Workaround... cant you use States for what you are after?
You could use a Simple State (which has a simulate port)
2012/7/10 Grahame Fuller <Grahame...@autodesk.com<mailto:Grahame...@autodesk.com>>
I couldn't repro your results in my quick tests. I got a few rogue particles moving when using If - a couple might have been self-collisions but others were puzzling. Mute was more reliable.

IsPassiveRigidBody also worked well. Did you remember to set their PointVelocity and AngularVelocity to zero? Passive RBDs don't react to forces but they do update based on velocity.

gray

From: softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com> [mailto:softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com>] On Behalf Of Alan Fregtman
Sent: Tuesday, July 10, 2012 03:46 PM
To: soft...@listproc.autodesk.com<mailto:soft...@listproc.autodesk.com>
Subject: Re: "Simulate Bullet Rigid Bodies" evaluates even when condition is False?!

For my need I went back to the... *shivers*... "classic" ICE RBDs, the ones which use bounding boxes.

They act reliably (sans exact collisions) and the node respects conditional confinements.


Sure is a nice "feature" how it evaluates different every time I run the sim though! ...Thanks RBDs!...
On Tue, Jul 10, 2012 at 3:38 PM, Jonah Friedman <jon...@gmail.com<mailto:jon...@gmail.com><mailto:jon...@gmail.com<mailto:jon...@gmail.com>>> wrote:
Also, you can't iterate on it and after it runs, it doesn't seem to set attributes like "pointPosition" or "orientation" in any normal way. I'm not a fan of the node either.
On Tue, Jul 10, 2012 at 2:42 PM, Alan Fregtman <alan.f...@gmail.com<mailto:alan.f...@gmail.com><mailto:alan.f...@gmail.com<mailto:alan.f...@gmail.com>>> wrote:
Tried that already and it's still doing something to my particles. Evil node!! :/
On Tue, Jul 10, 2012 at 2:38 PM, Stephen Blair <Stephe...@autodesk.com<mailto:Stephe...@autodesk.com><mailto:Stephe...@autodesk.com<mailto:Stephe...@autodesk.com>>> wrote:
How about muting the Simulate Bullet Rigid Bodies based on the condition you were feeding into the If?

And yes, I got the same thing with an If node.
I event tried plugging in a second, muted Simulate Bullet Rigid Bodies node into the False port
From: softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com><mailto:softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com>> [mailto:softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com><mailto:softimag...@listproc.autodesk.com<mailto:softimag...@listproc.autodesk.com>>] On Behalf Of Alan Fregtman
winmail.dat

Chris Chia

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Jul 11, 2012, 6:53:57 AM7/11/12
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Same here, can't repro this as both the if node and mute in the simulate bullet node are working.

Can you elaborate abit more on what you meant by
"Simulate Bullet Rigid Bodies", it STILL EVALUATES.
Chris
Sent from my iPhone

On 11 Jul, 2012, at 3:55 AM, "Grahame Fuller" <Grahame...@autodesk.com<mailto:Grahame...@autodesk.com>> wrote:

I couldn’t repro your results in my quick tests. I got a few rogue particles moving when using If – a couple might have been self-collisions but others were puzzling. Mute was more reliable.

IsPassiveRigidBody also worked well. Did you remember to set their PointVelocity and AngularVelocity to zero? Passive RBDs don’t react to forces but they do update based on velocity.

gray

winmail.dat

Mitchell Lotierzo

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Jul 31, 2012, 9:41:51 AM7/31/12
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I got to agree with Alan and Jonah. I'm trying to use that node within a state machine and it just crashes Softimage on playback. It was working fine when I was building it (was even evaluating right from state to state), but once I saved the scene and reopened, it just crashes on playback. I've had to resort to the regular "Simulate Rigid Bodies" as well, at least for the time being.

Mitchell Lotierzo

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Jul 31, 2012, 11:19:47 AM7/31/12
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Oops! Seems my original attachment was too large. Here's a link :)

Mitchell Lotierzo

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Aug 22, 2012, 3:49:56 PM8/22/12
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Just wanted to update this topic after Softimage Support got back to
me just in case anyone stumbles across the same issue in the future.
Here's the official response:

"
Hi Mitchell,

Thanks a lot for being able to send in a scene for our investigation.

I have investigated the crash and found it to be a known issue where
using states with a Simulate Bullet Rigid Bodies node will cause a
crash.

You may also wish to note that the crash has already been fixed in
Softimage 2013 SP1.
"
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