I would like to create something similar to a 3D Earth that gets city lights to shine only in dark areas… But differently. Instead of light, i’ll use shadow. I made this sample here so it’s easy to figure out what i’m heading at. The sphere has a checker texture… IT has voronoi light and shadow casted on it. I want the areas on the ball that are exposed to light to math add on the checker texture that are opaque, and the areas on the ball exposed to no light to diffuse nothing either…
Somehow, i would like the diffuse map on sphere to be more visible in areas exposed to voronoi light… And the transparent shader to be mixed with voronoi darkness… I’m not sure if it makes total sense gramatically but i hope with a picture it’ll be easy to figure out…
Basically… Black points should be transparent on sphere but opaque on white background… And it can’t be done in post-processing because i have to take into account the light bouncing so the object casts light and shadow correctly on the white sheet in the back.
Somehow… The shadow on the white sheet should have its checkboard black to have holes while the white areas should display generously transparent voronoi.
In production, i’ll use what i’ll learn here to make a material opaque on light and transparent on shadow.
Imagine blinds and car’s headlights in the night… The light moves through the blinds and the light moves around just like that voronoi texture… And there’s an apple. The apple gets to shine in its lightened areas… But it’s a ghost apple… So it stays transparent in the dark areas… Yeah. Ghost apple. That’s what i’m up to Now, car headlights goes through and the ghost apple gets sliced through by the light incoming. And the blinds’s shadow is casted down to up. And the shadow cuts through like razor blade in the wind. And the ghost apple gets visible and invisible at the same time, while blinds’s light and shadow keeps on sliding around the surface…
Shadow Test 1.blend (2.53 MB)
Straight-forward, 3d Earth is a very good example of what i want to achieve but only in a method where the texture naturally change from light to dark… And i’m unsure where to learn that refined need…
Transparent in dark areas… Opaque in light areas… Defined by incoming light… (voronoi)
Here’s another ghost. I like ghosts. They’re so familiar :3