Here’s a simple setup that I thought I’d share with you all. It is a way of emitting Thinking Particles as one object collides with another. The particles are actually emitted from the centre of the polygon of the colliding object, so not 100% accurate with the collision point, but hopefully you’ll still find it useful.

Xpresso Setup
The Xpresso isn’t too complex. Basically the Collision node checks if there is a collision occurring between the two objects, if there is it switches the PStorm node on.
To decide where the PStorm node should emit from the Polygon Selection is used and all the polygons from the object are iterated through. The polygon centre is then passed to the PStorm node and used for position.

Emit On Collision
Should be a nice preset to add to your arsenal of TP tools. Enjoy.
Download the scene file here (should work in r11+)