View Full Version : Boujou scene problems in LW - off frames

11-03-2011, 09:54 PM
Hey all,
Hopefully Ill be able to explain this well enough without confusion, but I also have screenshots attached to help explain.

I'm doing a test with Boujou and Lightwave to finally be able to understand how it all works. So far, after battling Boujou for a while, I was able to get a good solid camera solve, with test objects that stayed near perfectly in place (just a little sliding here and there).
All of the prediction points in Boujou stay perfectly in place with my track markers I laid out before filming.

But, when I bring my scene into Lightwave 9.6, nothing seems to match up and everything is noticeably off. I set my Boujou setup to 29.97fps, exported the scene to Lightwave at 29.97fps and using the image sequence at 29.97fps. I have also made sure that everything starts and ends on the correct frame. I have a 405 frame image sequence. Exporting from Boujou I have it set to frame 0-404, and the same in Lightwave.

When I first opened the scene from Boujou, I noticed the camera was on the opposite side of the axis, so I created a null at the origin, parented the camera to it and rotated the null 180' on its heading so the camera was now facing the scene properly.

I added a test object to see if everything lined up properly and I'm noticing the reference points dont match my image sequence and the object jumps around.

As an example, I compared the same frame numbers in Boujou and Lighwave, frames 141-143. In Boujou, the points stick perfectly to the track markers. In Lightwave, on frame 142, the points dip. (see attachment).
This happens throughout the scene and makes it very noticeable that the objects are not sticking properly.

I have been struggling with this all day and cant think of anything else to try. It looks perfect in Boujou, but off in LW. Are there any other tricks or big things Im missing, such as rotating the camera around the y-axis?
Any tips or suggestions would be great, I feel as though Im finally understanding it, then this happened. If anyone has any experience with this, Id love to hear your feedback.

Thanks in advance!

11-04-2011, 01:14 AM
I found that the camera's key frames started on frame 1, despite setting it up to start on frame 0. It didnt do much to help with the bouncing around. Still grinding away at this one.

Mr Rid
11-04-2011, 01:32 AM
I dont know Boujou well and have not used in awhile but I recall that it was always off one frame when I import into LW, even though I seemed to be doing everything correctly. I always double check that first.

I had only one scene that appeared well tracked in Boujou, but for some reason the camera insisted on winding up in a weird place in LW, that I never could find a simple correct for in LW.

Also, the camera often weirdly rotates 360 on the bank, between frames. Always check in graph editor.

11-04-2011, 01:52 AM
Thanks, Ill be sure to check those over.

11-04-2011, 04:49 PM
The camera's channels in the graph editor seem to be fairly smooth and uniform. There's only a few spots here and there that have a small spike. The whole camera path seems more jerky that the real footage, maybe it needs a camera keyframe smoothing or something along those lines.

Mr Rid
11-05-2011, 01:22 AM
A jagged graph curve may not be an issue. I usually make a 'tracking test' scene, by rendering a small disc/ball or two in an otherwise blank scene (to render quick), with no blur. Then lay the render over the plate in (AE, Fusion,etc) to check if it appears tracked well.

11-06-2011, 01:01 AM
That is a good idea. I rendered out a small test and it looks alright for more of it but still really jumpy. The other thing I didnt do is to take in account of lens distortion. I havent done any distortion tests but the more I read about it the more important it seems.
I guess I *hoped* itd be as easy as some people show it to be..I should know better :P
Still hacking away at it.

03-10-2012, 12:45 PM
It's very Simple

i Had the same error

Just go in Lightwave to "Image Editor" (If you set a Secuence Image as yor BackGround Composite)

And in "Star Frame" set to "1"

Thats Fix the desfasement :thumbsup: