More black backdrop problems
Posted: Wed, 19th Jan 2005, 9:05am
Post 1 of 4
Hi, when using things with black backdrops in Chromanator, i right click and choose add composite but the image becomes transparent. I've tried all the tool options and can't work this out. It happens with a white image on a black background and an image with black in it as well as the background. Any ideas guys
Posted: Wed, 19th Jan 2005, 9:09am
Post 2 of 4
That is how the Add method is supposed to work. You should only use the Add method when compositing light-based effects, like a lightsaber, or an explosion. For anything else, you should use the Luminosity Key.
Of course, a black background isn't very efficient, it's generally far better to use an alpha channel (if it is a computer generated image) or greenscreen.
Posted: Wed, 19th Jan 2005, 9:14am
Post 3 of 4
sorry i'm new to all of this, whats an alpha channel and how would a create an image with one in a 3d package for use in chromanator
Posted: Wed, 19th Jan 2005, 9:21am
Post 4 of 4
An image traditionally has three channels - red, green and blue. By adjusting these channels you can derive any colour you want. An additional channel - the alpha channel - contains transparency information. By using an alpha channel, the computer knows exactly how transparent every pixel of the image should be - so you don't need to worry about keying the image at all. If you import an alpha-channelled image into Chromanator, it will automatically use the alpha.
Regarding using alpha channels in your 3D program, you should check out the program's manual.