An Alpha hole through a scene ??

Hi,
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:
http://membres.lycos.fr/rompelstilchen/untitled.PNG
does anyone see what I mean ??
:stuck_out_tongue:
cya

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.

edit:
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.

Indeed,
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.