"Added" transparency

Is it possible to create a material where transparency is “added” instead of “mixed”, just like in video compositing software? (Using the Blender Internal)

Here is a sample image: the left plane is the standard transparency. The right one was added in video compositing (e.g. every R,G,B value of the texture is added over the background). A nice side-effect is that black areas are automatically 100% transparent.

Yes. Create a new texture and set it to ‘use nodes’. Then in the node window, create a new texture node and set it to use the texture shown in your render. Next, connect the texture panel to a RGB to BW converter node and connect that to the output node. Set your new texture to affect the alpha and the emission of the material.

Attachments

NodeAlpha.blend (80.7 KB)