Texture3D and volume renderin

[Irwin Zaid]

Hi all,

I've been playing around with VisPy over the last few days, and it's been fun. So thanks for that.

What I'd like to do is implement volume rendering in VisPy. I saw the post from Jonathan on this topic, and following that, I'm trying to do it with 3D textures -- in particular, the way Cyrille suggested.

From what I understand, this means first modifying VisPy's codegen to generate code for texImage3D and the corresponding constant GL_TEXTURE_3D. I modified annotations.py, adding texImage3D analogous to texImage2D. I also modified gl2.h, adding a #define for GL_TEXTURE_3D and an entry for glTexImage3D in the "GL core functions" part. This seemed to generate the right code, but I when I try to use gl.glTexImage3D(...) I get the error:

--

TypeError: glTexImage3D() takes 0 positional arguments but 6 were given

--

What am I doing wrong here? I'd be happy to implement volume rendering if I can figure out what needs to be done.

Cheers,

Irwin

[Almar Klein]

Hi Irwin,

I think it should be easier to take the code in gloo/texture.py and
create a 3D texture from that. You should then probably use glTexImage3D
from pyopengl.

We are still looking how we can provide this functionality in a nice
way. But probably this does not include changing our codegen, but taking
the necessary functions from pyopengl.

- Almar

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[Irwin Zaid]

Hi Almar,

Thanks for the reply. Okay, I'll do away with the codegen modifications.

I already have a Texture3D class in gloo/texture.py similar to Texture2D, so I'm with you on that. I'm just trying to get at glTexImage3D.

Should I just be using it via PyOpenGL directly, like "from OpenGL.GL import glTexImage3D" or is it already imported through 'gl' or something else in textures.py?

Irwin

[Almar Klein]

> Should I just be using it via PyOpenGL directly, like "from OpenGL.GL
> import glTexImage3D" or is it already imported through 'gl' or something
> else in textures.py?

Eventually it may be in gloo.glplus, or maybe in gloo.gl after you have
done gloo.gl.use('gl3') or something similar. See
https://github.com/vispy/vispy/pull/185 for some work in progress.

But for now, I propose you import from pyOpenGL directly ...

- Almar

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