Composited RGBA scene only saving one render layer, without effects. Fine when RGB.

I don’t know whether I’ve stumbled across a bug, or simply don’t know what I’m doing (likely the latter). I have a scene with two render layers, and I’m trying to composite it with a few special effects and save it as a transparent PNG. The problem is Blender will NOT save the composited image when RGBA is enabled - it’s only saving one of the render layers, without any of the composited effects on it! But it saves the composited image perfectly when the render output is set to RGB.

I’m using Blender 2.5a2 on Windows XP SP3.

My Node Setup:

My Output Settings (The problem doesn’t occur when I choose RGB instead of RGBA, but I need Alpha)

The Render Result (looks fine!)

But I press F3 and all it saves is this (it doesn’t do this when I render it as RGB instead of RGBA)… WTH!!!

Have you actually verified the loss of the alpha channel in a “real” image program? You are just looking at it in the Window previewer which does not show alpha. On top of that, you have confused poor windows by saving a TGA file as PNG. Make sure you are actually saving a PNG file as a PNG or a TGA as a TGA. Then open up your final result in Photoshop. GIMP, or even Blender to view the alpha channel.

Other than that, I can not help out unless you post the BLEND file.

looks like that leaf color does not have any alpha. Add your two alpha sockets from the render layers to feed the alpha socket in the composite node.

You are amazing! It shows what a little help from an expert can do. :eek:

Now if you don’t mind, one last question. I got the flower displaying fine now, but how do I carry over the alpha transparency of the glare effects into the PNG image? Here’s my node setup and the alpha channel it makes. Obviously, the alpha channel isn’t including the glare effects. What do I do?

easiest way is to buy my book from Amazon. or me directly :slight_smile:

or, you could play with feeding the glare output to a colorramp, where Black=0 alpha and white=full alpha, and adding that to the alpha channel; you will then have a partial alpha where it glows, and the color to go with it. When you then layer that over something, like in PS/GIMP, you will have a see-thru effect which will look like a glow.