anyone else having a prob. with extreme alpha in halo in this file?

Hi folks,
I was working on some stuff and stuck because I couldn’t save the alpha channel (with the rest of the picture) to a png file after rendering a halo with extreme alpha. Disabling extreme alpha renders also as I expected that it would do but saving the rendered image to a png works (includes the halo).

This is the file where the problem appears:
http://www.ontheserver.de/temp/Blender/plutonium1.blend

Can anyone confirm the loosing of the halo if you save the rendered image to a png file?

well, yeah. there is nothing behind the barrel, so it has an alpha of 0. Light has color, but no substance so if you render and then click and drag your cursor inside the image, you will see the colors and alpha at the bottom…0 alpha where the halo is.I would think, you want the barrel to glow, so you need to mix it into your surroundings, not alphaover it. Or add a texture to the area surrounding the barrel that has an alpha that fades away.

ah I see… well if that’s the problem I will just disable the extrem alpha function and save the image without the additional cool effect … probably

thanks papasmurf

I dont know what extreme alpha is, but if you disable that, and assign a texture to the halo material, mapped to alpha, and define the texture as a radial blend, you get the glow you are looking for.