compositing with plane?

I’ve just started getting my feet wet with compositing, and all the tutorials i see say to set up a plane in front of the camera, scale it to the camera field, set up the image/video texture etc.
this seems to me to be a completely backwards way of doing it. is there a way to either render the background image or to set a video as the backbuf? it takes ages to scale the plane to be exact, its either too small and has blue edges when i render, or its too big and crops part of the video. :frowning:
thanks. :slight_smile:

If you want a video as a backdrop, you can do it by loading it as a texture in the world buttons, and making the appropriate settings, also, I think in the latest versions, you can load a video into the back buffer ( haven’t tried it though ). another way, is to load the background image in the ‘view’ menu, use that to line your anim up, render with an alpha channel, and composite it in the sequence editor. There are other ways, too, I am pretty sure.

Have you considered trying out Blender’s node editor? Perhaps I’m not understanding what you want to accomplish, but combining imagery from different sources is exactly what the node editor is designed to do.

You can also stick the background into output // backbuff in the render panel

I found that you can do it with a sequence in the backbuf, ny typing "####.tga " or jpg or whatever. but if you load a video it stays on the first frame. :confused:

yes, if you want a video as the background to your 3D View, use the sequncer - load the movie in channel 1, the scene strip in channel 2, set the blend mode to alphaover, and click Do Sequence.

If you really want to use the plane method (even though the sequencer is much more effective), you can just set “WIN” under the “Map To” tab in materials for the plane. It will always fill up the entire camera that way.

i think you mean map input, and it didnt work anyway.

Jergling, using the 3Dcamera in the scene over a plane is far more flexible than the the simple sequencer. I would argue there is much more you can achieve but it depends upon requirements for a shot I suppose. There is a nifty script http://www.blinken.com/files/AddImage.py that will import and create an appropriate sized plane for an image/movie texture. Using an orthographic camera (no distotion) resizing and DOF effects, masking etc. can be achieved easier.

Of course just sticking 3d objects over a shot is easier the other way.