[GEM-dev] glsl sample3d textures

[Dave Griffiths]

> Dave Griffiths wrote:
> > Have you tried the noise command? It's in the spec, but I think it's hit
> > and miss how much vendors support it.
> > It's better to generate these procedurally to avoid the memory
> > requirements, I'm sure there is some perlin glsl source around if your
> > driver doesn't support it.
>
> my questions are a combination of learning glsl and testing the features
> of gem. I am trying to get some shaders work in pd that I found included
> in xcode. these shaders that have a bunch of code in a seperate file (not
> vert and frag). I don't know how to implement this in glsl_program or any
> other gem render chain...
>
> what is the noise command?

Sorry, I'm probably confusing things as I don't know enough about what you
are doing (or pd for that matter).

GLSL has a noise command in it's spec, for doing 1,2 or 3D perlin noise
lookups. On further reading though, this seems to be unsupported in the
majority of cases.

The thing is that to avoid having to deal with huge 3D textures it's best
to generate the noise procedurally (especially as it's procedurally
generated to begin with anyway). There should be some glsl code floating
around the net to do it (it's not actually that hard to do)

cheers,

dave