Today I will show you how to create animated flames like the ones used in my 3d character animation. Gimp will be used and GAP is also needed. This is a plugin that provides animation controls in gimp.
First right click on the layer and select Add alpha channel to add an alpha channel to the layer.
Clicking ‘OK’ will create a new file with a layer for each frame. The only downside is that a grey background is added rather than staying transparent. Don’t worry your hard work of removing the background wasn’t for nothing as it should now be easier to remove the plain grey background that is applied especially if the original background wasn’t a solid colour.
For a tutorial on installing GAP in Gimp 2.8 on Windows see here.
When the colour to alpha window comes up adjust colour by typing in the html notation noted from before (7f7f7f). This should remove the background from all the layers. Next we need to export all of the layers as images.