This might be a stupid question, but how to you change the opacity of something using nodes?
Transparent?
Transparent.
Moved from “General Forums > Blender and CG Discussions” to “Support > Materials and Textures”
However, your question is pretty vague. Nodes get used a lot for different things in Blender. Are you referring to material nodes, texture nodes, or compositing nodes? If it’s either of the first two, which renderer are you using?
I’m talking about compositing nodes and I’m using Blender’s internal renderer.
There are many ways to get this result.
I made a simple example of one method.
Here, in mix node, the seconary color changes opacity of the cube.
In that case, moved from “Materials and Textures” to “Compositing and Post Processing”
Another thing to keep in mind when dealing with opacity, especially if you have special-effects in mind, is that you will need to have illumination that does not consider the object’s presence (“sees through” it), as well as illumination that does (“shines upon it”). All of which “layer-specific lighting” is capable of doing.
What you ought to plan to do, then, is (first) to plan your shot, and (then) to make heavy use of “OpenGL Preview” renders at first. You need to work out what you need to do, then work out a node scheme that does it, and finally wind up with an OpenGL (quick …) render that’s exactly what you are looking for. Then invest the time in “real” renders of the various parts, as the situation calls for, knowing that what you’ll get, you can use.
The reason why I pointed out the need for separate lighting is that you’ll want to be able to “fake” the effect of light shining through the translucent object … to save time … especially if you intend for that translucency to change. OpenGL makes the initial rendering “cheap enough to fiddle with,” and it will be accurate. (Sometimes, it’s even good enough to be “finished.” OpenGL on modern hardware is quite powerful indeed.)