I need a method to scroll an image across all sides of a cube map in a way similar to scrolling a UV texture across a water's texture to give the appearance of movement by shifting the normals. I want to cause certain areas of the skybox to grow in intensity or lower to mimic a twinkle effect for the stars. I'm using a simple perlin noise map to do it, and I just need to find a way to scroll the texture on each side of the cubemap.
I've tried to shift the texture coordinates on the
samplerCube in GLSl, but it seemed to move the entire cube instead of just changing the coordinates that the cube gets the texture from.
I also tried using a regular
sampler2D, but that resulted in a screen of pure grey somehow.
What can I do to get this effect?