An Alpha hole through a scene ??

is there a way to apply an alpha texture mask between a scene and a backround scene
imagine a scene and there is a round shape through wich you see the background scene
like this:
does anyone see what I mean ??

there isn’t

closest thing you can do is make your scene not go over a line, possibly but having only certain geometry below that line and tweak the geometry so that the near or far clip can be used to slice across that line.

there is no official way. Maybe if the python script of one scene is run before drawing the other or something something can be done with blender.bgl [but not in the player]. this sounds like something fun to play with, got to see if it is possible to gldrawbitmap or something to the stencil buffer, or mess with the scissor test [which I don’t know much if anything about]

This would be trivially easy to do in the Sequence Editor, although it might require a third party plug-in. (I dunno; I haven’t thought it through that far.)

What you are describing is fundamentally a 2-D operation, to be applied between two “layers” of video information no matter how those layers have been prepared. That’s the domain of the Sequence Editor.

A layer containing a circle, with Alpha=1.0 in the circle and Alpha=0.0 everywhere else, would be used to select information from one of two layers, the foreground or the background, on a pixel-by-pixel basis.

that should be cool if we could use the sequence editor , also for real time 3d
I think it would allow people to create interesting scenes effects, fade in, fade outs and stuffs :slight_smile:

What about rendering the other scene, then using it as a texture in this scene but behind another wall? Wait, that’s what your asking, right? I thought it was another scene as in portal stuff. Newbie here. You want some kind of dynamic alpha transparency.