How to render a Bullet Physics Simulation in Maya 2015?

[An3Drea]

Hi everyone!

I need help about a Bullet Physics simulation.
I cannot render it in mental ray batch mode. If I render a shot at any frame of the simulation mental ray works but if I want to render the entire simulation in batch mode the result is always the same first frame.

I tried the alembic export mode with the options described in the "Autodesk Help" but doesn't seem to work (it creates the alembic file but the script editor gives to me this message:// Error: No valid root nodes were specified. //).
I tried to bake simulation in "old style" but the results in batch render is the same.

Where am I wrong?

Thanks

[danimateit]

Did you ever find a solution to this.  I'm having the same problem.

Thanks,

[agraham]

Did you guys follow the workflow example from this page:

http://help.autodesk.com/view/MAYAUL/2016/ENU/?guid=GUID-C0C66CE1-A2BB-402E-AA16-49F58E8BFB8E

It shows how to do exactly what you're doing. I have a feeling there's a step missing. You need to select the top node of the hierarchy BEFORE bringing the Alembic data into the scene, that's why it's saying 'no valid root nodes were specified'.

[syracoj]

If your Bullet Simulation contains a single mesh that has had bullet applied to it:

  -select the mesh that has bullet applied to it

  -Bullet Menu > Export Selection to Alembic (this one essential exports a transform with the animation data on it)

  -in a scene with that object where no bullet has been applied, select the object

  -import alembic w/ import under current selection + Merge options

You can select the mesh of a Bullet Sim also:

  -select the mesh that has bullet applied to it

  -Cache Menu > Alembic Cache > Export Selection to Alembic (this one acutally exports geometry to alembic (bigger file size))

  -file > new

  -import alembic w/ Import To Scene Root option

If your Bullet Simulation contains a rigid set (collection of objects under a single transform) with NO Created Output Mesh:

  -select the Set named BulletRigidSet 

  -Bullet Menu > Export Selection to Alembic (this one essential exports a transform with the animation data on it)

  -in a scene with that object (collection of objects under a single transform) where no bullet has been applied, select the top transform

  -import Alembic w/ import under current selection + Merge options

  -Alembic will be applied to that top group/transform node

If your Bullet Simulation contains a rigid set (collection of objects under a single transform) WITH Created Output Mesh:

  -select the Output Mesh

  -Cache Menu > Alembic Cache > Export Selection to Alembic (this one acutally exports geometry to alembic (bigger file size))

  -in a scene with that object (collection of objects under a single transform) where no bullet has been applied, select the top transform

  -file > new

  -import alembic w/ Import To Scene Root option

Let us know if you have any problems. 

We looked at the posted link to the docs page and are looking at improving it.

[Hugiell]

Syracoj, I tested your solutions and they all work. Although Autodesk documentation in generally pretty good, you described it even better here.

I get two warnings when exporting to alembic (without mesh):

// Warning: |pCone1|pConeShape1 is an unsupported type of kMesh //
// Warning: |pCone1|bulletRigidBodyShape2 is an unsupported type of kPluginLocatorNode //

but it works.

Thanks

[your_niceguy]

Just a little addition to your guide. I wont take anything away from it, because it's very thorough and very helpful!

The only thing that had me confused was that you didn't write that the import is to be found under "Cache"... not under "File" 🙂 I guess that part quickly becomes natural: (atleast this is the case with Maya 2019)

So, updated to current standart:

If your Bullet Simulation contains a rigid set (collection of objects under a single transform) WITH Created Output Mesh:

  -select the Output Mesh

  -Cache Menu > Alembic Cache > Export Selection to Alembic (this one acutally exports geometry to alembic (bigger file size))

  - in a scene with that bulletSolver object (collection of objects under a single transform) where no bullet has been applied, select the "bulletSolver" in the outliner

  -Cache > Alembic Cache > Import Alembic []

  -Import To Scene Root.

Then you get the polygon version of your solved rigid set.