Can we write our own sampling and wrapping logic in shader? what could be a problem?

Question

There are some ideas I would like to do in shader that require me to make a weird texture topology, texture atlas packing for example. They could not be wrapped with common wrap mode, there would be glitch or bleeding on the edge of UV seam

And so I think, what if I just use tex2D() or tex2Dlod() for texture lookup with point filtering, and then rewrite all sampling and blending logic in the shader itself, look up for many points with custom wrapper and blend them with shader code

Is it possible and what could be a problem or disadvantage about this method?

Answer 1

Yes, this is possible and common. You will need to set the filter and/or wrap mode of the texture asset itself, in the project. (if using shader graph, you have the option to specify a custom sample state inside the shader itself). You can certainly modify the UV coordinates passed to your shader, and use those modified values to sample the texture(s).