Retime SOP squashes and stretches RBD sim objects

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Hello,

I have created a simulation of falling vegetable pieces into water. Then I have taken the cached water sim and by using retime SOP I have created the slow motion effect. When I try to do the same with falling cached vegetable pieces I get them randomly squashed and stretched when using RETIME SOP. I have searched different websites for any clues and I have tried lot of stuff to fix it, but it didn't work.
Does anybody know how to fix it?

Many thanks for your help.

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Example_1.jpg (1.6 MB)

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Hello, is the topology consistent?
It looks like there might be some problems with ids or not enough data to interpolate. Do you have “timeblend” before the retime node?
It'd be nice to have a scene example too
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Make sure you are retiming packed geos (or the rbd points before using them to transform pieces)
To interpolate rotations correctly

Because if retiming unpacked, each geo point will interpolate independently resulting in deformation you see
Tomas Slancik
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deviner
Hello, is the topology consistent?
It looks like there might be some problems with ids or not enough data to interpolate. Do you have “timeblend” before the retime node?
It'd be nice to have a scene example too
deviner
Hello, is the topology consistent?
It looks like there might be some problems with ids or not enough data to interpolate. Do you have “timeblend” before the retime node?
It'd be nice to have a scene example too

Hello and thank you for your answer. Yes the topology is consistent. To manipulate the time I have used the Lab/Retime node which includes timeblend and timeshift. But as you suggest the problem might be the insufficient data to interpolate. The pieces are rotating quite fast during the real time simulation so there might too big gap between frames. I am placing here the scene. There is one active GEO node where is the retiming happening.

attach]Indukcni_nadobi_ToExamine.hiplc

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tamte
Make sure you are retiming packed geos (or the rbd points before using them to transform pieces)
To interpolate rotations correctly

Because if retiming unpacked, each geo point will interpolate independently resulting in deformation you see

Thank you for your answer. To use packed primitives was one of the first ideas how to solve it, but as soon as I use packed primitoves the retiming node doesn't interpolate the substeps. It just keeps the position of the simulated objects over fxp 5 frames, then shows the next frame of the sim and again keep it the 5 frames. The substeps are missing and I have the option to interpolate between input frames on the retime node active. Here is the scene. There is only one active GEO node which consists the retiming node. Any idea?
attach]Indukcni_nadobi_ToExamine.hiplc

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Indukcni_nadobi_ToExamine.hiplc (3.7 MB)

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I meant keep it packed before you apply the dopnet sim, so that the transforms are applied to the packed prims and stored in intrinsics, then retime can interpolate those transforms
if you already have it unpacked and then assemble after sim, the transforms are not gonna be preserve so there will be nothing to interpolate except for position of the centroid
Edited by tamte - Nov. 17, 2020 11:21:02
Tomas Slancik
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tamte
I meant keep it packed before you apply the dopnet sim, so that the transforms are applied to the packed prims and stored in intrinsics, then retime can interpolate those transforms
if you already have it unpacked and then assemble after sim, the transforms are not gonna be preserve so there will be nothing to interpolate except for position of the centroid

Thank you. I got confused with the message which shows when applying the RBD Fractured Object for multiple objects insised one GEO node. It says “Use RBD packed objects unless you need the RBD objects to interact with other solvers like fluid etc.”. Can I have just one question about the situation when I have a static object with static solver, RBD packed objects + bullet solver and fluid solver. The bullet solver takes the bullet representation of the static object and the fuid solver takes the RBD representation of the static object (volume reperesentation) or the fluid solver usese the bullet representation (convex, concave etc.)?
Many thanks for your help.
Edited by ALLCITY - Nov. 18, 2020 09:19:50

Attachments:
RBD fractured objects_1.jpg (3.0 MB)

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