All-frequency shadows

OpenGL OpenGL: Advanced Coding
1

I saw this paper, “All-Frequency Shadows Using Non-linear Wavelet Lighting Approximation” in here .

The paper doesn’t have many details though, so implementing it is difficult. Has anyone tried this? Do you know of any other places where one can get detailed information about this method?

Any help appreciated. :slight_smile:

Thanks

Antonio

2

Depending on what you want to accomplish, there’s probably a more ready method for implementation than this one.

  • You need a geometry sampler like you would need for spherical harmonic PRT. Ng does this with hardware (render a 64x64 cubemap at each vertex).

  • You need to project samples into the basis functions. Ng does this with a Haar wavelet transform.

  • Compression is done by truncating coefficients.

  • You need a fast inverse wavelet transform for playback.

Not that I have tried this, or that I would be aware of any other implementation :smiley:

3

Yeah, I saw that paper earlier too, and also couldn’t find a lot of specifics.

If so then, there are math libraries to do the matrix multiplication, and wavelet transforms and such on the gpu ( gpgpu ), which works very fast. I certainly hope that it works as well as the video shows :slight_smile: . Perhaps it can be even faster :slight_smile: . Though, I think to take advantage of the sparse matrix stuff, it would really have to be done on the CPU (perhaps I’m wrong, check that website).