   Particles to grid for GPU marching cubes?
  I'm going to use either the geometry shader or histopyramid to do marching cubes on GPU to get fluid surface.  The fluid is PhysX hardware fluid.  So I have two questions:- how do I get access to the particles directly in VRAM so I don't have to send them to the CPU and then back for rendering- how do I sum the particles into the density grid that the marching cubes uses efficiently on the GPU? this is an issue since going linearly through a list of particles with unrelated location is unworkable, due to the inability to write to all slices of a volume texture simultaneously. I could invert scatter into a gather assuming I can access on the GPU whatever grid PhysX uses to accelerate neighbor search for the simulation, but that goes back to the first question   
  Anyone?  Even partial answer might be helpfulWould maybe passing a GPU address made with glGetBufferParameterui64vNV (bindless graphics) or a glGetBufferPointerv with a bound buffer texture, to PhysX as the location to put the particles in, work?   ;  I've never really done a whole lot of work on the GPU, but I've been playing with CUDA lately and they have a marching cubes demo on the GPU that you can check out   ;  The issue isn't the marching cubes, as I already have GPU code for that.  The issue is getting to the particles PhysX simulates while they're in GPU memory, rather than doing a pointless GPU->CPU transfer only to send back to GPU.   ;  that is a very good question... i too would like to know   ;  Again, I don't know a lot about this area -- especially PhysX, but given that PhysX is an NVIDIA product and integrated with CUDA, could you use texture memory with PhysX and create a CUDA kernel that uses that texture memory?  I know in CUDA you can specifically refer to texture memory you create.  Is it possible with PhysX?   ;  It's not really an answer to your question, but if you want to consider alternative approaches then the GPU Gems 3 article on 'Point-Based Visualization of Metaballs on a GPU' might be interesting. You can read it online at http://http.developer.nvidia.com/GPUGems3/gpugems3_ch07.html;Can't you just bind a shader/texture/whatever when the particles' render function is called? what more are you after?   ;  What are you talking about? What particle render function? PhysX writes particles into a buffer the user provides.   ;  in lesson 114.... line 178 they iterate through the buffer in the CPU... if it could be done on the GPU I imagine it would have been done there.   