OK I’m having a weird problem. Well, weird to me but probably not surprising to someone more versed in blender.
I’ve created two concentric spheres. The inside sphere has a series of textures on it to make it look like a planet (color, normal, spec…). The outer sphere has a series of cloud textures on it. The first is mapped to color and set as a stencil, the second is nearly identical and is mapped to normal and alpha.
Well, the clouds are correctly rendered with the dark portions of the cloud texture being transparent, the clouds have neat little bumps on them to catch the light, and so on. The trouble is, where the clouds are transparent, you can see right through them to the starfield image I have as a backdrop to the render. The planet sphere inside the cloud sphere is totally invisible.
How can I prevent the transparency of the outer sphere from affecting the inner sphere? The objects are distinct, they’re not joined or even grouped. Shouldn’t I be able to see the inner, non-transparent sphere through the outer, mostly transparent one?
Help? 
