Hi

I am working on particles with curve flow. In the runtime expr, I need to query the information about the curve 's tangent at the project point of the particle onto the curve. Then I used a MEL cmd "pointOnCurve" to get the info.

The prob is that this cmd is called for each particle every frame. In other word, when I have just abt 500 pats, the scene seem to hang oredi.

I tried an alternative: add an vectorArray attr (per-particle) and create a node using API to compute the tangent needed and connect to particle node. However, it seems that I can't connect from my node to the per-part attr.

Is there a way to speed up the evaluation of the cmd pointOnCurve??? (when i take out this cmd, the animation is damn much faster)

Any help is kindly appreciated