Vertex Colors Not Being Passed Around In The Dg

[bobhopeless]

I have a node derived from MPxDeformerNode and I need to set some vertex colors inside its "deform" function.
I'm using MFnMesh's setVertexColors to do it, but the colors on the resulting mesh don't update on the viewport unless I force an evaluation for example by "dgdirty myNode1.outputGeometry[0];". The actual deformation updates just fine though.

You can see the same phenomenon in the next case also:

CODE
polySphere -ch 0;
polyCube -ch 0;
move -r 2 2 2;

setAttr "pSphereShape1.displayColors" 1;
setAttr "pCubeShape1.displayColors" 1;

connectAttr -f pSphereShape1.worldMesh[0] pCubeShape1.inMesh;

Execute the above first, so you now have the polySphere1 outputting its mesh to the polyCube1 and you can see the shape of the cube has been updated to a sphere.

Now change the colors of the polySphere1:

CODE
polyColorPerVertex -rgb 1.0 0.0 0.0 pSphereShape1;

And you see the pCube1 hasn't changed its color. The colors will update after:

CODE
dgdirty pSphereShape1;

What's also interesting is that if you connect the polySphere1 to polyCube1 by its outMesh instead of worldMesh[0], then there's no problem. So I assume that my deformer being connected by its outputGeometry[0] its problem is of a similar kind.

So how can I force this color information to propagate from inside my deform function? Any ideas. Thanks.

[bobhopeless]

Okay, I did a quick test and wrote a simple deformer by deriving this time from MPxNode and making my own inMesh and outMesh attributes. No problem in changing the colors of the vertices inside the compute function of the node. Everything updates just fine when you change the node's attributes.

It seems to me this is a Maya DG evaluation bug and it's really annoying because i'd like to derive my deformer from MPxDeformerNode class and get all the fancy stuff like set membership editing and deformer reordering for free.

[joojaa]

I dont think its a bug, but rather a acceleration feature. Anyway what does your attribute affects block look like.

[bobhopeless]

Simply four custom attributes affecting outputGeom

CODE
attributeAffects( iterations, outputGeom );
attributeAffects( maxRelax, outputGeom );
attributeAffects( tintUncalculated, outputGeom );
attributeAffects( lockBorders, outputGeom );

The first two attributes are integers and the second two are booleans.