Creating transparent glass with an image texture w/ alpha channel

Question

I'm trying to create a glass block and have it so the light color changes according to the glass color.

I want a lighting effect like the blue glass (texture-less) block, but with the "streaks" of the glass blocks provided by the image, as well as the glass color.

Top: Non-textured glass block, with the intended lighting effect seen on the background Bottom left: Blue Glass block w/ image texture Bottom right: Glass Block w/ image texture

I want the blue glass block to cast a blue shadow, but it's casting a gray shadow. The plain glass, however, is fine. Both images have alpha channels.

Texture-less block node:

Glass block nodes w/ image texture:

I've used glass, transparent, and translucent shaders in a "mix" in various combinations with no luck. The shadows remain the same.

Answer 1

I found a solution to your problem. The answer lays within the lightpaths. You want your direct rays with your texture and alpha and your indirect (Colored shadows) using a solid blue object. This can be done fairly easy inside the nodes.

So, this shadow:

With this texture:

This is your solution:

One material will be used when rendering the cube and the other one when rendering the shadow. The Lightpath node will output white when the ray is directly coming from the object to the camera. Black if it isn't.

Answer 2

After more research and testing and almost giving up lol) I think I've found the key... Node setup for Blue glass: Output (rendered view, Cycles): Viewing the block with no background:

Usage: Change the color in the Transparent BDSF. This is the 'shadow color' The image texture is what's used to display the block without light passing through it.