Hi,
I'm trying to understand the Gem motiontracking objects, but I don't seem to get very far. The help patch of pix_movement shows the difference between two subsequent frames, but when I connect pix_blob (set to the alpha-channel) after [alpha] in the rendering chain, I have no clue what the relation is to the xy-coordinates that come out and the movement I see in my frame. When connecting pix_multiblob after pix_movement, the xy of'showblob' seem not to have any relation with the movement I see.
Some questions:
- what are the x/y coordinates in relation to my Gem window (defined in
pixels) and the x/y coordinates of the objects [translateXYZ] or [pix_showblob]? Or are the x/y coordinates related to the geo (defined in units) on which I texture my image?
- Does [showblob] represent the movement? Let's say that if we have a
red background and a green moving ball, showblob is following this green ball? Or is my understanding completely wrong/backwards?
- Can anyone explain the definition of units, when p.e. rendering a
rectangle of 3/4 in a gemwin of 800/600? I understand that 'units' are logical sizes in a 3d-application (from: Gem manual), but is there anyone who found a way to explain this better?
Did someone succeed in making a simple motiontracking-patch, just so I can understand how these objects work?
Thanks a lot, Sara