GPU marching cubes example

examples
#1

Hi All!
I ported a GPU marching cubes example to OF from http://www.icare3d.org/blog-techno/gpu/opengl-geometry-shader-marching-cubes.html, and added in parametric surface calculation on the GPU. The code is here… (for XCode 4)
https://github.com/chriskiefer/MarchingCubesGPU

Chris

1 Like
#2

Very cool stuff. It’d take me a week to wade through those geometry shaders and understand everything in there, so it’s nice to have something running that I can check through and toy with to help me get it a little better. I found the strange bug too :slight_smile:

You might want to comment out the ofxMaxim inclusion in the project that you uploaded.

#3

Great! this code was one of my dreams in OF! i know that code…i have run the original windows version time ago.i will try to use it in linux and windows OF. It is interesting because use a geometry shader to build the marching cube. Sure it will help us to undertand beter many things.
Many tanks!

#4

hi, @luma I was able to use your example in Ubuntu 11.04. However, I had to make changes to your code:

  1. I had to rename the file mctables.cpp to mctables.h
  2. resulting in marchingCubesGPU.cpp # include “mctables.cpp” to # include “mctables.h”
    Other than that it works perfectly!
#5

this is crazy! works perfectly for me right out of the box. is it possible to download the geometry back to the cpu after it is generated on the gpu?

#6

I think you might be able to do this with transform feedback (see http://www.opengl.org/registry/specs/NV/transform-feedback.txt), but I’ve never tried this so I’m not sure how it works.

#7

just tried the code on a macbook pro with a NVIDIA GeForce 320M and looks like the shaders do not behave correctly: it only renders fragments of the sphere and I’m getting this error:

  
Validation error: Validation Failed: Sampler error:  
  Samplers of different types use the same texture image unit.  
   - or -  
  A sampler's texture unit is out of range (greater than max allowed or negative).

I have some free time, I’ll try to look deeper into the problem

#8

Hi @naus3a,
i think the error message may be misleading for helping to find the fault - I get that error as well on my machine as well (330M) even though the code works on it - I think it may be that the validation check gets called too early.
Chris

#9

ok, thanks: then I’ll simply poke my fingers around until I find what is not displayed correctly :slight_smile:

#10

Could you please explain what this function does for (3 == curData)

void marchingCubesGPU::prepareToDraw()

Thanks for your work.

BR
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