Bizarre roto problem

Hiya,
First post, sorry it’s about a problem.
Basically, I’m having a real issue with roto’ing an arm & hand. Neither the arm or hand are doing any wild gestures. They remain static, but the camera moves and rotates in on them over three seconds.
I’ve completed an initial loose track on the forearm which seems to have worked OK, followed by two roto splines, one for the hand & one for the arm, both linked to the initial track. For the majority of the scene, everything works fine, but on just one frame, for no apparent reason, the splines go crazy! You can see the problem in the images below:
Image: http://www.furious-productions.co.uk/Forum%20Uploads/mocha-01.jpg
Image: http://www.furious-productions.co.uk/Forum%20Uploads/mocha-02.jpg
Image: http://www.furious-productions.co.uk/Forum%20Uploads/mocha-03.jpg
As you can see, the frames before and after are fine, it’s just on the one frame I get the problem.
Any ideas? It’s certainly got me stumped!:confused:
Cheers,
Andy

Hiya,

First post, sorry it’s about a problem.

Basically, I’m having a real issue with roto’ing an arm & hand. Neither the arm or hand are doing any wild gestures. They remain static, but the camera moves and rotates in on them over three seconds.

I’ve completed an initial loose track on the forearm which seems to have worked OK, followed by two roto splines, one for the hand & one for the arm, both linked to the initial track. For the majority of the scene, everything works fine, but on just one frame, for no apparent reason, the splines go crazy! You can see the problem in the images below:

Image: http://www.furious-productions.co.uk/Forum%20Uploads/mocha-01.jpg

Image: http://www.furious-productions.co.uk/Forum%20Uploads/mocha-02.jpg

Image: http://www.furious-productions.co.uk/Forum%20Uploads/mocha-03.jpg

As you can see, the frames before and after are fine, it’s just on the one frame I get the problem.

Any ideas? It’s certainly got me stumped!:confused:

Cheers,

Andy

As an addition to this, I exported my shape data for a test in After Effects and it was a disaster! Even the layers that look fine in Mocha are a mess in AE :(. On frame 0, all looks OK, but every mask layer on every frame after that in AE looks like image 2 above.
I wonder, could it be an issue with bezier layers? My initial rough tracks were done using the X-Spline tool and if I import them in to AE, they work just fine. However, the more detailed roto layers linked to those tracks were created using the B-Spline tool. As I mentioned earlier, they all look fine in Mocha but are corrupted in AE.
Here’s hoping I don’t have to start all over again!
All the best,
Andy

As an addition to this, I exported my shape data for a test in After Effects and it was a disaster! Even the layers that look fine in Mocha are a mess in AE :(. On frame 0, all looks OK, but every mask layer on every frame after that in AE looks like image 2 above.

I wonder, could it be an issue with bezier layers? My initial rough tracks were done using the X-Spline tool and if I import them in to AE, they work just fine. However, the more detailed roto layers linked to those tracks were created using the B-Spline tool. As I mentioned earlier, they all look fine in Mocha but are corrupted in AE.

Here’s hoping I don’t have to start all over again!

All the best,

Andy

Thanks Mary. You’re spot on, as the track does indeed go off the screen towards the end, although not until well after the ‘crazy frame’ occurs. Sadly, I fear the solution will be of little use, as I would still have the problem I mentioned in the second post.
As an experiment, I tried using only X-Splines for tracking & roto. They seem to import in to AE just fine, so I decided to suck it in and start all over again.
Since my first post, I found and watched your video on roto for 2D - 3D conversion. I must say I picked up some valuable tips for roto’ing a person. More tracks of smaller areas results in less keyframes needed for the roto, greatly speeding up my workflow :slight_smile:
Thanks for all your help,
Andy

Thanks Mary. You’re spot on, as the track does indeed go off the screen towards the end, although not until well after the ‘crazy frame’ occurs. Sadly, I fear the solution will be of little use, as I would still have the problem I mentioned in the second post.

As an experiment, I tried using only X-Splines for tracking & roto. They seem to import in to AE just fine, so I decided to suck it in and start all over again.

Since my first post, I found and watched your video on roto for 2D - 3D conversion. I must say I picked up some valuable tips for roto’ing a person. More tracks of smaller areas results in less keyframes needed for the roto, greatly speeding up my workflow :slight_smile:

Thanks for all your help,

Andy

Hi Andy,
Yeah, when the track goes crazy and behind the camera like that, usually the only solution is to start that shape over. I generally use x-splines because they work better with scaling according to our planar track than “b-splines”.
I’m so glad you enjoyed the roto demo and got some useful information out of it, I’ve got a few more in the works coming up.
Good luck on your project!
Mary

This looks like the surface plane of the track might be going beyond the camera, try turning on the surface and grid and seeing what that is doing when you track.
Cheers,
Mary

This looks like the surface plane of the track might be going beyond the camera, try turning on the surface and grid and seeing what that is doing when you track.

Cheers,
Mary

Hi Andy,

Yeah, when the track goes crazy and behind the camera like that, usually the only solution is to start that shape over. I generally use x-splines because they work better with scaling according to our planar track than “b-splines”.

I’m so glad you enjoyed the roto demo and got some useful information out of it, I’ve got a few more in the works coming up.

Good luck on your project!
Mary