I am trying to map a simple texture map onto a cube, with an alpha map to take out any extra...looking to have a transparent cube with leaves mapped on one face, nothing else. Any tutorials out there for Alpha channels? Do they need to be black for what you want to keep, and white for the image to hide? Help.. also, I'd like to use rotoscoping for putting movies on objects, moving leaves, similar to the technique in RustBoy. Thanks.

The simplest way of doing what you want is to use a Multi Channel Mixer shader. In Source 1 load your leaf texture map (or just choose a green color) in the color channel. Make sure the Transparency slider is at 0. In Source 2 choose Complex Shaders, Single Channel, set the channel to Transparency then the shader to Value 100%. Then in the blender channel load your black & white trans map for what you want leaf and what you want transparent. You may need to invert the color which will switch things if you've got it the wrong way round. You can use movies as texture maps, just load in the same way. Two keyframes will appear in your timeline, drag the right hand one across until the end of your animation. If you want the texture movie to repeat double-click between the two keyframes then select Oscillation tweening in the Properties tray, choose Sawtooth, set Up Phase to 100% and adjust Oscillations for the number of loops you want. HTH Mark

Thanks Mark, I was successful to a point. The alpha channel for the texture map worked well, but the movie texture map did not. I used the same map (movie) and inverted the color. It worked, but since the movie colors of the leaves were green, they became semi-transperent... A possible work-around: Record two movies, one with textures ( leaves ) and one with leaves textured in white? Keep all motion setting same but change so I have a black background and white leaves? Any other ideas? Thanks for your help. What does HTH stand for? Highland Tech. High? R.

HTH - Hope This Helps. If you do 2 renders like you say it should work. Make sure you don't have anything like Glare or Blur on though, since they would blur your edges and give you strange edges to your transparencies. And for that matter, any level of grey will be a level of transparency, so you may be better trying a non-photorealistic setting, or a Toon setting for your render so that the leaves are 100% white and everything else is 100% black. GL! (Good luck!) ;>

Yes, as bluetone says, your transparency map in the blender channel (either still or movie) needs to be black and white with no shades of gray. That means that any lossy compression formats will tend to make the edges of your leaves fuzzy. Sequenced bmp or tiff would be the best method. In theory you can load sequenced images (numbered image000000.bmp, image000001.bmp, etc.) as a shader texture map and it will run as a movie but there appears to be a bug in C3 that stops this working so load as an uncompressed avi (or similar) instead. I made a sequence of four bitmaps in Photoshop, just black leaves on a white background moving up and down and (using C2) loaded them successfully as the transparency blender into a shader, with just green for the colour. I applied this to a vertical plane to see the effect and it worked quite nicely. Glad to be of help. Mark

Thanks for both ideas, I was able to render twice. The second, black and white worked great! I'm still working on mapping to a shape that displays the leaves well, but that's another job. I included a number of lights, turned shadows off, and was able to get white leaves. Yeah! R.

Great. For a shape, try an oval in the vertex modeler, put a few links across the shape and add in some more vertices so you can control it, then pull up the center to make a sort of upside down dish. Mark