Godot: Add support for 3D textures

[BastiaanOlij]

I'll see if I can find time to tackle this myself, for now I'll work around it with a slightly costly 2D texture with slices, but with more and more techniques relying on GL_TEXTURE_3D to do lookups in a 3D texture, especially where procedural materials are concerned, it would be nice to have support for this :)

Any input given on how to best add this into the engine and whether there are platform concerns I need to be aware off would be very welcomed :)

[aaronfranke]

Can you give an example of what 3D textures are and when/how they are useful?

[Bauxitedev]

I second this.

@aaronfranke They are just textures with another dimension, so you have width, height, and depth. This would enable stuff like

• volumetric effects, like smoke, fluid, fire, dust, etc
• GPU based voxel terrain rendering/generation
• GPU based 3D particle collision
• 3D particle flowfields (like Unreal Engine 4)

And many more interesting things.

[BastiaanOlij]

@aaronfranke it's for doing stuff like this:
https://www.youtube.com/watch?v=y7tQTtODTZ8

Here I've 'faked' it by putting slices underneath each other in a 2D texture but it means I can't use the optimizations in the GPU for doing 3D texture lookups with filtering.

But you can do many more nice things with it

[Chaosus]

@akien-mga I guess this should be closed via b4d3f541e761d257199104a10f53260fa149690c

[aaronfranke]

There's also edde52c8dea0193111239b6b2f002adcc24ac0c9 which broke other things but may have fixed this issue.

[Bauxitedev]

Cool, this is actually possible now... Is there any documentation for this feature? What 3D texture formats are supported?