Not sure if this is a bug or missing feature but point clouds do not seem to work for RiCurve.
Attached are 3Delight/Pixie comparison renders of point based occlusion.
This is interesting, but I did not understand the scene and the problem.
Do you mean 3D occlusion baking? It seems you have a lot of geometry here. Is there a small file you can upload (with the shader)? Also what are you caching (seems like occlusion)?
Sorry, looking back over the post I guess it was kinda vague :-/
I've added a zip with sample ribs that hopefully makes it clearer. This is exported using MOSAIC's full setup so it would be kinda involved to try and separate just the occlusion parts, hopefully its not to cluttered to follow. If it is let me know and I'll try to separate out just the parts needed for occlusion manually ;-)
This is just the standard baking of area data into a point cloud and reading it bake in the beauty with occlusion(). In this example I dropped the curve count from 10000 to 100 and made them wider. You can see what seems to be black dots on the curves, as the curve count increases and they are made smaller it ends up being completely black. I've also included an example 3Delight render for comparison.