Question by sunny8751 · Jan 01, 2019 at 12:20 AM · shaders transparency shader programming stencil

Shader that renders pixel with highest alpha value?

How do I create a shader that, at each pixel, renders the object with the highest alpha value (AKA most opaque) while ignoring more transparent pixels, regardless of their z depth?

I'm very new to shaders, but I read about Stencil shaders and was wondering if you could compare the reference values using the alpha value of the object. The shader would not have additive alpha blending, etc.

I currently set the alpha value of my objects using a custom Mesh by setting the colors of the mesh's vertices in script.

I've created a simple demo below, with three quads with varying transparency values overlapping. As you can see, although the white square has the highest transparency value in the middle, you can still see a hint of blue and red over the white. alt text