Tracking??/

I’m not sure if this is possible or even if i can do this in blender or what program i need. I have attached an image from a sequence. What i would like to do is replace the green card with a photo. So if I move the green card in the video it will look like i am moving a photo. If this does not make sense please let me know. Does anyone know what this process is called or even how to go about doing it?

Attachments


google voodoo. it’s free tracking, integrates with blender, and there are youtube video tutorials on how to use it.

You then have to texture a plane with your picture - see wiki on mesh editing, materials, and textures. Use a shadeless plane material.

Then use the match-move to move the camera so that plane stays aligned with the card.

Then key on the green and substitute in your rendered plane/image for the tracked plane, see wiki on matte nodes and greenscreening.

I looked into voodoo but it seems to only move the camera. Don’t I need to track and move that object instead?

Papa i have seen your posts on Voodoo before and gave it a try lastnight. It seemed to work 20 frames in and then the camera just seems to fall and not move anymore. Any ideas?

yes you do.
no clue on voo doo (giving up). try following a video tut on youtube. sounds like some setting somewhere.

Papa any idea to the issue above

You need to do 2d tracking on the paper, you can do it with a composition package like combustion or after effects. If you only need to track few frames you can do it by hand inside blender:
-load your sequence as image background.
-create a plane with your photo uv mapped on it.
-align your plane to the green paper on camera view on the first frame.
-add a hook (ctrl H -> add to new empty) to each vertex of the plane (in edit mode)
-in object mode go frame by frame moving the emptys to match the paper corners.
-in node compositing, load your sequence, do a keying on it, to take out the green paper, and an alphaover with the render of your plane with the photo.

Hope this helps.

vico