tl;dr How can I add UV’s to a ShaderMaterial that repeat per face?
I’ve been banging my head around this all day and I know it must be something really simple (stupid) but I just can’t see it
I made a custom buffer geometry that is just a flat plane (code taken roughly from the built-in PlaneGeometry) but modified it so it is flat on the Z-axis. I also add some custom attributes to allow a texture per face (through a sampler2DArray). This all works wonderfully (see screenshot):
I know which corners should be faded through an attribute. The technique I’m trying to mimick is described here: opengl - How can I render a textured quad so that I fade different corners? - Stack Overflow
The problem I have is that my UV-coordinates stretch around the entire plane, instead of going from 0 to 1 per face (or index?). The textures render perfectly, but I need to figure out where the face starts and ends based on UV coordinates.
I have 2 sets of UV’s on my plane.
uvs.push(ix, 1 - iz); uvs2.push(ix * gridX, 1 - (iz * gridZ));
uvs rendered as a texture (this is the one that is used to render the diffuse textures - this works (although the UV looks strange - the edge colors are at the very top):
uvs2 rendered as a texture:
So what I’m after is uvs2 repeated 100x100 times so that I can access the current position by simply grabbing a
fract of the UV. (e.g.:
float x = fract(vUv.x); // 0-1)
If I do this:
gl_FragColor = vec4(color.rgb, color.a * (1.0 - vUv2.x));
I expect the result to be that each tile on the plane fades out from left to right. Instead the entire plane is fading.