Some Mocha AE "?basics?" that I need to understand

Hello All
I really don’t know if this is as basic as I feel it probably is but I need to ask these questions to know if I am wasting time or not.
I have a wedding ceremony that I recorded and I have 1 clip that I want to track so I can stabilize it. My camera was pointed down the aisle that the bride came in on and there are pews full of people on both sides of the clip I am using. Those people are moving around, my camera is being held by my hands and there are a 2 or 3 big shakes that I doubt mocha will track through. Also there is a bit of zooming out as I took the shot. Here is a still of my starting point:
Image: http://alanrtonn.files.wordpress.com/2012/07/imagineer-post-pic2.jpg

  1. I am working on stabilizing this shot. What does the new stabilize button on the tool bar do? Do I need a shape for it to work?
  2. When I track an area should I manipulate the points on the shape to match new areas of the plane I am tracking that appear? Meaning should I watch through and move the points of the shape on the surface in the clip that I am tracking?
  3. Would it be better to create a shape on the surface in the clip I am tracking and then create exclusion shapes over the objects that are going to get in the way? For instance the people in the pews move around and will end up getting in the way of the back wall that I am tracking. Should I put exclusion shapes on them?
  4. Related to that, if I were to track the floor as well as the wall, would that help? and then there are the pews. they have these flat surfaces on the end at the aisle and I was thinking I could use those as well.
  5. Should I start at the beginning of the clip or the end? At the end I have more backwall visible than at the beginning, but I also have less because the Bride and her Father are in the way.
  6. Should I let Mocha do the whole clip, or as much as it can, and then make shape changes and then ReTrack?
  7. How do I get rid of all tracking data? Lets say for whatever reason I want to purge the current track and start again, how do I tell Mocha AE to flush the last track? Or do I just track over and get new data?
    I have used Mocha before but it has been a while, I never used it for stabilization and I had used it about 2 versions ago…
    Any and all help appreciated.

Hello All

I really don’t know if this is as basic as I feel it probably is but I need to ask these questions to know if I am wasting time or not.

I have a wedding ceremony that I recorded and I have 1 clip that I want to track so I can stabilize it. My camera was pointed down the aisle that the bride came in on and there are pews full of people on both sides of the clip I am using. Those people are moving around, my camera is being held by my hands and there are a 2 or 3 big shakes that I doubt mocha will track through. Also there is a bit of zooming out as I took the shot. Here is a still of my starting point:

Image: http://alanrtonn.files.wordpress.com/2012/07/imagineer-post-pic2.jpg

  1. I am working on stabilizing this shot. What does the new stabilize button on the tool bar do? Do I need a shape for it to work?

  2. When I track an area should I manipulate the points on the shape to match new areas of the plane I am tracking that appear? Meaning should I watch through and move the points of the shape on the surface in the clip that I am tracking?

  3. Would it be better to create a shape on the surface in the clip I am tracking and then create exclusion shapes over the objects that are going to get in the way? For instance the people in the pews move around and will end up getting in the way of the back wall that I am tracking. Should I put exclusion shapes on them?

  4. Related to that, if I were to track the floor as well as the wall, would that help? and then there are the pews. they have these flat surfaces on the end at the aisle and I was thinking I could use those as well.

  5. Should I start at the beginning of the clip or the end? At the end I have more backwall visible than at the beginning, but I also have less because the Bride and her Father are in the way.

  6. Should I let Mocha do the whole clip, or as much as it can, and then make shape changes and then ReTrack?

  7. How do I get rid of all tracking data? Lets say for whatever reason I want to purge the current track and start again, how do I tell Mocha AE to flush the last track? Or do I just track over and get new data?

I have used Mocha before but it has been a while, I never used it for stabilization and I had used it about 2 versions ago…

Any and all help appreciated.

Hello and thanks for responding. I have some follow up questions to your reply.
So after reading through your post and some time thinking about things I think that it might be better to make a shape that ?fits? the back wall and then put on exclusion shapes? What I mean is currently I am putting my track layer points ?around? the area of the wall in back that is visible to track. if my tracking shape is simply a search area, I was thinking that if I made it the full size of the wall in the back of the clip and then put exclusions on it that I would have less work moving points around. There would be a lot of exclusions and I would start at the end of the clip, but that would give Mocha a lot to work with. Does that sound like a good plan of attack?
?Anything that is solid will work for stabilisation, but not a combination of different planes, as you will not get accurate data?
If I did them on 1 layer or 2? See currently I have both the wall in back and the floor tracking and it seems to be working well but each plane is on a different layer.
I have been getting some good tracking happening but I was thinking about changing my plan to what I described above. I don?t like the idea of throwing away what I have done in case my plan doesn?t work so I was wondering, if I create new layers and tell Mocha to track them and make the previously tracked ones invisible does that ?turn them off? and keep the tracking data they have? Or should I save the project as? something new and start over with that?

Hello and thanks for responding. I have some follow up questions to your reply.

So after reading through your post and some time thinking about things I think that it might be better to make a shape that ?fits? the back wall and then put on exclusion shapes? What I mean is currently I am putting my track layer points ?around? the area of the wall in back that is visible to track. if my tracking shape is simply a search area, I was thinking that if I made it the full size of the wall in the back of the clip and then put exclusions on it that I would have less work moving points around. There would be a lot of exclusions and I would start at the end of the clip, but that would give Mocha a lot to work with. Does that sound like a good plan of attack?

?Anything that is solid will work for stabilisation, but not a combination of different planes, as you will not get accurate data?

If I did them on 1 layer or 2? See currently I have both the wall in back and the floor tracking and it seems to be working well but each plane is on a different layer.

I have been getting some good tracking happening but I was thinking about changing my plan to what I described above. I don?t like the idea of throwing away what I have done in case my plan doesn?t work so I was wondering, if I create new layers and tell Mocha to track them and make the previously tracked ones invisible does that ?turn them off? and keep the tracking data they have? Or should I save the project as? something new and start over with that?

Hello again
I am having trouble figuring out the best way to handle my shot. I have started at the begining and the end and i am finding that i am spending way to much time “playing” with things. I was hoping that this would be a lot more automatic.
no matter what i do near the end i have a huge amount of trouble trying to keep the shot stabilized. either i am moving exclusion layer points around or those of the tracking layer or both. i know that Mocha isnt a magic bullet but i was hoping that i would be done with this shot a lot quicker.
http://alanrtonn.wordpress.com/2012/08/05/more-problems-so-more-pictures/
If i need to i can upload the clip. but for the moment can anyone give a little help on how to approach this?

Hello again

I am having trouble figuring out the best way to handle my shot. I have started at the begining and the end and i am finding that i am spending way to much time “playing” with things. I was hoping that this would be a lot more automatic.

no matter what i do near the end i have a huge amount of trouble trying to keep the shot stabilized. either i am moving exclusion layer points around or those of the tracking layer or both. i know that Mocha isnt a magic bullet but i was hoping that i would be done with this shot a lot quicker.

http://alanrtonn.wordpress.com/2012/08/05/more-problems-so-more-pictures/

If i need to i can upload the clip. but for the moment can anyone give a little help on how to approach this?

Send me the shot and I will go though it:
martinb[at]imagineersystems.com

Hi DawnTreader, i’ll answer your questions back in the same format:
1. I am working on stabilizing this shot. What does the new stabilize button on the tool bar do? Do I need a shape for it to work?
The stabilize button on the toolbar is a preview tool only. It locks down your tracking information so you can see if there is any drift in your track.
2. When I track an area should I manipulate the points on the shape to match new areas of the plane I am tracking that appear? Meaning should I watch through and move the points of the shape on the surface in the clip that I am tracking?
As the footage reveals new planar information you have 2 main options: You can stop the track and either move shape points or add additional shapes using the Add Spline to Layer tool. Furthermore you can add layers above the tracking shape to mask out obstructions (such as people getting in the way).
Moving the spline will not affect the track, it will only redefine where to search. Unless you are using adjust track or are tracking in Manual mode, moving the surface does not affect the track.
3. Would it be better to create a shape on the surface in the clip I am tracking and then create exclusion shapes over the objects that are going to get in the way? For instance the people in the pews move around and will end up getting in the way of the back wall that I am tracking. Should I put exclusion shapes on them?
To get the most information to track, using exclusion masks is advisable. You can either choose to create a rough garbage mask around the whole crowd, or mask out individual problem areas, or both.
4. Related to that, if I were to track the floor as well as the wall, would that help? and then there are the pews. they have these flat surfaces on the end at the aisle and I was thinking I could use those as well.
Anything that is solid will work for stabilisation, but not a combination of different planes, as you will not get accurate data. Since you will probably not need to use perspective stabilisation, this may not be an issue.
5. Should I start at the beginning of the clip or the end? At the end I have more backwall visible than at the beginning, but I also have less because the Bride and her Father are in the way.
Either way is fine since you can always add more shapes to the same layer to catch more data. In general we suggest to start tracking from the point in time where the plane you are tracking is closest to the camera, but this may not be an issue in your case. We also recommend tracking from the clearest point if there is motion blur or DOF.
6. Should I let Mocha do the whole clip, or as much as it can, and then make shape changes and then ReTrack?
I would suggest tracking and modify as you go. Sometimes it is good to see how far mocha can get first, as sometimes mocha can surprise you how well it will ignore an obstruction or hold onto a tiny scrap of texture.
7. How do I get rid of all tracking data? Lets say for whatever reason I want to purge the current track and start again, how do I tell Mocha AE to flush the last track? Or do I just track over and get new data?
Which version are you using? You have a few options:

  1. You can retrack from the beginning, but if you have added any shape keyframes be aware they will animate and might throw off the track
  2. You can switch to Mnaual mode and press the “Delete All” keyframe button on the timeline to remove all internal keyframes
  3. You can just delete the shape and start again (I usually do this if I am starting from scratch)
  4. If you have mocha V3 you can go to the Dope Sheet, navigate to the tracking information and delete the keys
    I hope this helps!

Hi DawnTreader, i’ll answer your questions back in the same format:

1. I am working on stabilizing this shot. What does the new stabilize button on the tool bar do? Do I need a shape for it to work?

The stabilize button on the toolbar is a preview tool only. It locks down your tracking information so you can see if there is any drift in your track.

2. When I track an area should I manipulate the points on the shape to match new areas of the plane I am tracking that appear? Meaning should I watch through and move the points of the shape on the surface in the clip that I am tracking?

As the footage reveals new planar information you have 2 main options: You can stop the track and either move shape points or add additional shapes using the Add Spline to Layer tool. Furthermore you can add layers above the tracking shape to mask out obstructions (such as people getting in the way).

Moving the spline will not affect the track, it will only redefine where to search. Unless you are using adjust track or are tracking in Manual mode, moving the surface does not affect the track.

3. Would it be better to create a shape on the surface in the clip I am tracking and then create exclusion shapes over the objects that are going to get in the way? For instance the people in the pews move around and will end up getting in the way of the back wall that I am tracking. Should I put exclusion shapes on them?

To get the most information to track, using exclusion masks is advisable. You can either choose to create a rough garbage mask around the whole crowd, or mask out individual problem areas, or both.

4. Related to that, if I were to track the floor as well as the wall, would that help? and then there are the pews. they have these flat surfaces on the end at the aisle and I was thinking I could use those as well.

Anything that is solid will work for stabilisation, but not a combination of different planes, as you will not get accurate data. Since you will probably not need to use perspective stabilisation, this may not be an issue.

5. Should I start at the beginning of the clip or the end? At the end I have more backwall visible than at the beginning, but I also have less because the Bride and her Father are in the way.

Either way is fine since you can always add more shapes to the same layer to catch more data. In general we suggest to start tracking from the point in time where the plane you are tracking is closest to the camera, but this may not be an issue in your case. We also recommend tracking from the clearest point if there is motion blur or DOF.

6. Should I let Mocha do the whole clip, or as much as it can, and then make shape changes and then ReTrack?
I would suggest tracking and modify as you go. Sometimes it is good to see how far mocha can get first, as sometimes mocha can surprise you how well it will ignore an obstruction or hold onto a tiny scrap of texture.

7. How do I get rid of all tracking data? Lets say for whatever reason I want to purge the current track and start again, how do I tell Mocha AE to flush the last track? Or do I just track over and get new data?

Which version are you using? You have a few options:

  1. You can retrack from the beginning, but if you have added any shape keyframes be aware they will animate and might throw off the track
  2. You can switch to Mnaual mode and press the “Delete All” keyframe button on the timeline to remove all internal keyframes
  3. You can just delete the shape and start again (I usually do this if I am starting from scratch)
  4. If you have mocha V3 you can go to the Dope Sheet, navigate to the tracking information and delete the keys

I hope this helps!

Although it is more initial work, making one shape and then creating masks for the occluding objects can be more beneficial.

If you just turn off the visibility and tracking for the already tracked layers they will be fine where they are.

Although it is more initial work, making one shape and then creating masks for the occluding objects can be more beneficial.
If you just turn off the visibility and tracking for the already tracked layers they will be fine where they are.

Send me the shot and I will go though it:
martinb[at]imagineersystems.com