The manual book that came with Carrara 3 have very little information about alpha channel. I tried to put leaf texture map with the tree in Carrara 3. It did not remove the background. I put either full black or white, c3 still will not remove transparent it. I rather not to use adobe photoshop because I have thousands texture to import in. Most are with alpha. Did you have any success with alpha channel? Thank you in advance.