sooo how do I render so I dont an alpha variant image like :D<that smily? I want to be able to have an invisible backround so I can have a image that works well on 2D layers without a large square around it messing things up
In scene buttons (F10) enable ‘Premul’, ‘RGBA’ and choose an output format that supports alpha channels, e.g. PNG. More info on this [in the docs.](http://wiki.blender.org/index.php/Manual/Output_Formats)
Hope it helps, happy blending!
Yes, it works quite well. thank you! also, is there a way to render out just the shadow of an object in this same way?
To only get the shadow (with propper alpha) you can do the following:
Your ground plane (or whatever receives the shadow) needs a material with “OnlyShad” activated (“Shaders” tab). The object casting the shadown needs a material with “Only Cast” enabled (“Links and pipeline” tab - wonder why these options are on different tabs; maybe there should be a dedicated “Shadows” tab?). Otherwise same settings as describes above.
Note: You will see a completely black image in the render window, this is correct, save the file and check in an alpha-aware viewer.
I’m sure you could also use nodes/render layers for this, but I’m too tired right now to have a look
While MPPIC gets some well-deserved rest, let me chime in and say Render Layers, Sha (Shadow) only button enabled (Combined and Z disabled) will deliver the shadows pass only. See docs - Render Layers for more info and how to use them.