Pass more than 4-channel data to OpenGL or Vulkan

Question

I would like to pass the following values as a texture to the fragment shader:

• Base R
• Base G
• Base B
• Material switch (metal/dielectric)
• Normal x
• Normal y
• Normal z
• IOR (Only for dielectric)
• Roughness

That is a lot of stuff. It looks like this would require three different textures in OpenGL. Questions:

• Are there any extensions to OpenGL that makes it possible to pass this as one texture?
• From what I have understood about Vulkan, GPU memory is more easily accessible. Does this mean that you can use generalized texture formats?

Answer 1

Even in Vulkan, you can not have more than a four channels for a texture. However, both in OpenGL and Vulkan, you could use a 32 bits by channels texture, and use something like packUnorm( https://www.khronos.org/registry/OpenGL-Refpages/gl4/html/packUnorm.xhtml ). But it works only with integer texture and you will have to perform filtering by yourself

Another way could be to use something like SSBO ou TBO. But I do not understand what the problem is by using 3 textures.