Maya geometry instances to Houdini engine input

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11 posts
Joined: Sept. 2017

I am working on a heavy scene in Maya where I had to use geometry instancing to make it less taxing on my workstation.
Does Houdini engine support geometry instances coming from Maya? I'm currently dealing with over 80 million triangles in terms of instanced geometry.

Or do I have to make my HDA do the instancing under the hood to re-create the scene in Houdini?

Any help or direction would be greatly appreciated.

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146 posts
Joined: Oct. 2017
At the moment, the engine plugin does not support bringing in instances from Maya. If you attempt to connect multiple instances to a single input, it will connect one copy of the leaf geometry, but we only connect the first transform for each leaf geo. The houdiniInputGeometry node currently only supports a single transform input.

The houdiniInputTransform node supports a multi of input transforms, but there's no convenient UI to connect it to anything except locators. You could still script connecting the world transforms of all your instances to a houdiniInputTransform. Which would create a particle geo with one particle for each transform, with the transform data tacked on as point attributes. You could then rebuild the scene in your hda.

We need to revisit the way that the Maya engine deals with input transforms and instances and DAG hierarchy. Any additional feedback is welcome.

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13 posts
Joined: May 2019
For me this is currently the biggest issue with using Houdini Engine for Maya.

I absolutely love it, but working with instances inside of Maya is so useful that it's a pain every time I want to pass my geometry through HE.

I'm happy to hear that you're looking at improving this, Julia!

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