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View Full Version : Camera matching - boujou related

n3no
07-26-2007, 06:18 PM
Hi all!

We're testing a solution for camera matching for a building scene we are on.

So, we've shot in HD from a helicopter the place where there should be this building.

I've broke footage into tiff sequence so boujou can handle it better than avi or mov - at least that is what i ususaly do for comb*.

I've tracked the thing with boujou and it works pretty fine. I've put the bug to test scene rotation and it is there laying on the same floor - after rotating predicion points...

My problem is that when i import that camera into 3ds max camera orientation and scale don't match with the building I already done.
So my guess is, is there a way to import in boujou a piece of geometry and make a first camera position with rotate and move to make my sample geometry fit the image? I would give this first prediction that boujou would track the rest. At the end, when I imported camera to max i would go exactly to the place it belong..

All I have been seeing in boujou is - first they track the footage and then they build geometry around that tracking. This time I already have my scene built so I want to go the other way around.

Are there any boujou users that can give me a hint on what direction to go?

Thanks a lot!
MarlonPerez
07-26-2007, 06:44 PM
Hello n3no,

Honestly, 90% of the time I use boujou for my personal projects, I tracked first then I modeled. That was always the simplest way to accomplish the task. But in recent work I didn't have that luxury because my client already had models built, so on and so forth.

So there were two solutions, each dependent on the shot (Nodal Pan or Free Move). For the nodal pans we scaled the boujou data in max using the backdrop of the first frame. For most scenes this worked perfectly enough that we could manually adjust any additional frames later on which weren't much maybe once in the middle and end of the sequence.

For the free camera moves it was a little more tricky, once we tracked the footage there was no way to scale the boujou data in max because it would scale out of the backdrop image. So What we did was insert a box and align the box along the 3 axis' until the perspective was correct and from there we manipulated the camera to come in to focus with the backdrop, boujou data and scene geometry. We experienced slight camera slipping but not enough that we couldn't fix.

Hopefully you understand the technique. I wish I had the scene files so that I could post a mini tutorial. Maybe I'll try to find something after work and post something up. Also when I came up with the technique it was my first time importing tracking data into 3ds max and it was really difficult for me to get used to. Maybe since you're more well rounded in max you could have an easier time with it.

Hope this helps.
n3no
07-27-2007, 10:10 PM
Hi Marlon!

Thanks for sharing.
It is true, for free camera it becomes a pain... I've tried putting all points and camera in a group and the align this with geometry for the first frame.

Obviously that worked for the first frame only because of scale problems.

I'm now stabilizing video first wich is also a pain but I think I can handle better.
I'll try a new aprouch, if I can remember one, when I finish stabilizing.

I'll try to keep you up with how I managed.

Cheers and have a great weekend.
nelson
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