I generate 3 displacement textures in every frame for an ocean. I use the three textures for cascading. But what is still needed is an effective mechanism to break the texture tiling.
I thought of texture bombing. This works quite well in the fragment shader with dFdx and dFdy. But I need the mechanism analogously in the vertex shader so that the effect in the vertex shader with the displacement textures is synchronous with the normal textures in the fragment shader. In the fragment shader I have dFdx and dyFdy so that I can work with this for texture bombing:
But in the vertex shader there are no dFdx and dFdy. Does anyone know of an analogous function to dFdx and dFdy in the vertex shader?