How to get UVmap-point of particle collision

Hi,
does anyone know how to get the texturecoordinates of an RigidStatic at the particle collision point?

I want to read and write in the texture on every collision point. (Do i need the PxSimulationEventCallback::onContact(…) method or is this function not for particles?)

Thanks for reply.

Does anyone have an idea?

I tried to use the onContact()-method but the function is never called when an particle collides with a rigid static actor. I have also set all pairsflags to eNOTIFY_TOUCH_FOUND in the filter function but nothing happens.
I have forgotten something?

Someone has an advice?