hi guys, I'm newbie to physx. My problem is that how to activate collision detection between fluid particle and terrain mesh. I watch the sample execution program SampleParticleFluid.exe and found the 8th sample inside this file maybe what I want. However, when I look over the sample code about this program, I found no clue where my implementation differ with the sample. As least for terrain part, I code almost the same with the sample. However, in my implementation, fluid particle directly go through the terrain mesh and fall to the ground plane. In the Sample, the particle fall down to the terrain mesh and even have friction with terrain mesh. Can any body tell where is the key to activate the collision detection as what I mentioned above?