Binding a specific mip level of a texture for writing?

[scewpsdev]

Hey everybody,

I'm generating some 3D textures at runtime and I would like to create mipmaps for them.
These are the options I'm currently aware of to do that:

• generate mips on the CPU and upload them individually
• create a framebuffer for each mip level, attach the texture and render to it
• write a compute shader that writes to the texture using imageStore

All of these options seem to not be possible for my use case.
At the moment I'm generating the mipmaps on the CPU but of course it is very slow, especially with bigger textures.
I can't use framebuffers because my textures are 3D and not 2D. I've read somewhere that you can attach each 3D texture layer separately to the framebuffer but that's very impractical and maybe not even possible at all with bgfx.
The third option would be the most suitable and flexible for my situation but unfortunately it seems like it's not possible to only bind a specific mipmap level to the compute shader to use imageStore with it. I've read that it's possible to do that with vulkan, and that there is even a vk extension that allows you to write to any mipmap level directly in the shader with imageStoreLod.

Am I missing another option that would solve this problem? Or maybe it is possible to implement binding specific mipmap levels only (which would be useful for many use cases).

Thank you in advance,
Scewps

[pezcode]

setImage() has a parameter to specify the mip level to bind

[scewpsdev]

Thank you very much, that did the trick. I did not know there was a special function for compute shader images. Exactly what I was looking for 👍