I have setup a series of object indicies for different objects in my scene.
I have enabled the index pass for the render layer and I see the IndexOb connector in the nodes window. I have created four IDMask nodes to process. I have connected the IndexOb to the input of all 4 IDMask nodes. I connect the output of the IDMask node to a viewer to verify my results.
But the only one that seems to contain the correct data is the one linked to index #4? Index #4 contains seven objects. Some are curves and some are meshes. Some have modifiers and some do not. If I change the index of one of the objects from the #4 ID set to #3, it does show up in the #3 set.
If I change one of the objects in the #2 set to #4 it will not show up in that set either.
My scene, of course, is too large to post.
So what prevents an object from participating in a ID Mask node?
This may be silly but did you do a full render after assigning the passindexes? I forgot to render a layer once and had a devil of a time figuring out that was what was left out.
Thanks for the tip, I did do a full render and I disconnected and re-connected the nodes. I am aware there are refresh issues in the Node system, but this one does not make any sense to me.
I think I figured it out.
Blender nodes are not smart enough to see through alpha mapped planes. What a bummer.
I have a series of planes in my scene with alpha mapped animated image sequences. Some of them are in front of the objects I had assigned to the various ID groups.