I'm trying to create an atmosphere shader for a planet. As usual, the atmosphere is a sphere that's just slightly larger than the planet sphere inside.
The shader is to have a cloud map. My problem is that I need a tranparency map to matte out the areas between the clouds, but I also need to map a ramp texture transparency map onto the facing ratio so that the clouds fall off to complete transparency at the edge of the planet, but I can't seem to figure out how to have both transparency maps exist at the same time. I've tried a layered shader, with the "falling off at the edge" transparency in first position, but it didn't have the effect I was hoping for, which was making everything go completely transparent at the edge.
Please help. Planets with hard edges just don't look real.
you can chain connect nodes using the color gain, something like using the facing ratio to drive a ramp node and in the color gain plug the other shader you need. or you can use 2 spheres, one for the outer part and one for the inner parts.