I’m trying to render the Earth, I have hi-res (4k) colour/specular/bump maps, where can I get a good Blender-useable cloud texture with an alpha layer ?
Or - this is more of a Blender related question and might even be easier - I already have some clouds with an alpha layer in PNG format, what type of image must I convert them to to use the alpha in Blender ? And with what free program can I do this ?
I know these questions have been asked before, but I can’t find the threads.
i think you can use the pngs in blender, but i convert them to jpgs with gimp.
Well, pngs don’t show up in the menu when I try to load them as textures, so I guess Blender can’t use them.
I’ve never used gimp, but I thought converting to jpgs would get rid of the alpha because jpg doesn’t support it ?
You can do it by using two jpgs. One is your cloud image. The other is a greyscale version showing only the alpha channel. Pure white will be totally transparent while bure black will be totally opaque. Grey areas will be partially transparent. Simply place this texture on another channel and turn on the Alpha buton. Be sure to turn off Col. You may be able to use the same image for both, but using Gimp, Photoshop, or other image processing software to generate the alpha map will be more accurate.
you could use Targas (TGA) as they support an alpha channel too and can be loaded in Blender.
Martin
Thanks to both of you !
I found some jpgs to use at my favourite real-planet texture site,
http://gw.marketingden.com/planets/
Thanks for the tga format thing, I’ve been wondering for a while which format uses alpha in Blender. Unfortunately none of my current image software supports the alpha channels so they don’t convert properly (I really ought to get the gimp!) so I’ll stick with the jpgs.