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Hegs
05-21-2006, 10:50 AM
Hi,

Im starting using boujou (and 3d tracking in general) and Im going thru some tutorials. However in the masking tut (invloving a pan with a car moving thru the shot), I am required to track the car and background seperately. The bit I can't work out is how do I match up both camera tracks in 3ds max so that everything fits.

The instructions say:

Load both exports into your 3D animation package. Make sure you are at the first frame of the sequence and line up the camera for the moving object with the camera for the background. To do this make sure that the top node of the moving object hierarchy has the same pivot point as the camera below it.

Constrain the top node of the moving object hierarchy to the position and orientation of the camera for the background.

Remove the constraints and make the top node of the moving object hierarchy the child of the camera for the background.
Im having great difficulty getting this to work, and was wondering if anyone could make it a little clearer, and more 3ds max-specific. Thankyou very much for any help at all,

Hegs
beaker
05-22-2006, 05:40 PM
Just export the camera for the car as a static camera with moving points. Then you can just import that into the camera track for the plate.
Hegs
05-24-2006, 12:46 AM
thanks,


Its more the importing process i don't get. In basic terms, this is what i thought i have to do:
1) Import moiving camera/still background track (Call this Track A)
2) Import the still camera/moving car track (Track B)
3) Align all of Track B (inc all the ref points) with Track A, by aliging both cameras.
4) Parent Track B's camera so that it follows Track As camera.

So ultimately you end up with the cameras from each track aligned and moving exactly the same, as if it were just one camera.

Is that correct?

ps. Im just thinking what might be the problem - in step 4 should I parent just the Camera from track B or the entire track?
Hegs
05-24-2006, 02:49 AM
Ahh dont worry - i worked it out..what i didnt realise was that I had to manually move the pivot point of the top node of Track B (the static camera track) to the pivot point of the camera.


Anywaysss..my next question is -
a) Why would you ever want to track a moving object in a scene?
b) If I wanted to, for ex, add a CG attachment to the top of the moving car, how do I use the track to help me do this?
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05-24-2006, 02:49 AM
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