Adding custom deformer to a skinned mesh

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Utkarsh Agnihotri

Jul 5, 2021, 7:47:36 AMJul 5
to Python Programming for Autodesk Maya
Hi, everyone,
I am trying to write a custom deformer and it is working well with single mesh with no inputs like skincluster, blendshape, wrap deformer etc. But when I try to run it on a mesh with multiple deformers, it throws me a cycle warning. Can you please tell me how can I avoid this in maya api?


Marcus Ottosson

Jul 5, 2021, 8:24:31 AMJul 5

Cycle warnings come from the way nodes are connected, rather than the API (assuming you mean maya.api.OpenMaya or the C++ API?). The warning means that one or more output attributes in your plug-in is causing one or more of the of the input attributes to evaluate. For example, if the mesh.outMesh is connected to yourDeformer.inMesh and yourDeformer.outMesh is connected to mesh.inMesh, that would be a cycle if inMesh is used to compute outMesh. I would disconnect all of them, and reconnect each of them one at a time until the warning makes an appearance. You can also comment-out all of your attributeAffects() calls, which is what determines which plug should cause another plug to evaluate.

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Utkarsh Agnihotri

Jul 5, 2021, 8:30:06 AMJul 5
to Python Programming for Autodesk Maya
Hi Marcus,
Thanks for the reply.
I am using python maya api 1.0 .
The problem is that I am not able to anything because scene crashes so it's hard to test through connections. I will try using attributeAffects. 
I am trying to effect the mesh based on intersection by using closestIntersection , so there is no secondary output. Is it a good way to operate on the source mesh?
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