Stabilization


#1

Hi,

thanks for the support in this forum. I have questions:

if you have a shaky horizon and a shaky car/snowboarder is it possible to stabilize the horizon and the shaky object in front of the camera? Both?

I think something in the wobbly image has to wobble when you stabilize?

And is it possible lock the pan on a stabilized shot? Or will the pan has to change in order to stabilize?

Thanks


#2

Is this for standard or 360 video? We can stabilize both but the methods are different for each.

For standard stabilization, use the Mocha Pro stabilize module. For 360 footage, use the reorient module in Mocha VR. Each method will need a track to base the stabilize off of. Normal footage will need something closer to the camera to stabilize the camera motion, 360 footage does better with tracks near the horizon. You can really only stabilize one track at a time, even though you can use multiple layers to stabilize. Your best bet is going to be to try to lock down the object you’re trying to stabilize with a track and go from there, but the shot will be animated around that object, so use the parameters you need (sometimes shear and perspective can give weird results in stabilization).

For more in depth breakdowns, see our “Getting Started” videos: https://borisfx.com/videos/?tags=category:Getting%20Started&search=

Cheers,
Mary


#3

Thank you. It is for 360 video. So you really could have a result that has a straight calm horizon and a stabilised car when in the original shot everything shakes?

“will be animated around the object” - yes, and after that you can stabilize the surroundings while have a stable object? I tried that and the result is a mix of both, not perfectly stable horizon and a decent stable object.

Stabilizing and masking 360 is very time consuming and render intensive. I underestimated that.

So you would suggest to test the stabilization with shear/perspective off too?


#4

At a certain point this is a compositing / vfx issue. You can track and stabilize parts but you can only take things so far. You can track and stabilize the horizon, and do the same for the car, and if you can come up with a good place to composite those 2 passes then you’re good.


#5

No, if the horizon is stable the car won’t be, most likely.

You will be stabilizing around the horizon. It will, however, look smoother in general. You might find the car looks fine when you’re done.

Tracking 360 footage and rendering it is definitely render intensive.

For 360, you actually leave shear and perspective on. So don’t worry about that in Reorient.


#6

thanks. i get slowly get used to the work flow. problem is still to remove something in stabilzed footage that pans when the car drives a curve. the clean plate dont pan with the track.


#7

If the clean plates are not following, the track isn’t rock solid. The remove is only as good as the track. Try tracking more texture.


#8

thank you - this could be. i try.

I recognized that a remove layer that is linked to the background-track has a better remove behaviour.

in your video tutorial it says that you dont need to link the remove layer to the bg-track. i think that holds only for kind of static objects.


#9

No, the remove layer uses the BG tracking layer to remove. It doesn’t matter if they’re linked at all no matter what. :slight_smile:


#10

I think it is impossible to stabilize everything in a scene when there is a moving camera that is not following a single forward facing vector. I’ll do my best to describe why I think this below. I hope I’m wrong, because I would love to hear a solution to the problem I’m about to describe.

Lets say we have a foreground object (a pole) and a background object (a wall) that are, say, 10 ft apart, and both objects are not moving. The camera is, say, 5 feet in front of the pole and pointing directly at the pole. There is a dot on the wall directly behind the pole which the camera does not currently see because it is pointing directly at the pole; so, the pole is blocking the view of the dot. We’ll take three pictures all pointing directly in the direction of the dot. First picture, we take a picture with the camera moved one foot to the left and pointing at the dot on the back wall which it now sees because we moved left. Second picture, we take a picture of the scene from the front with both objects inline, therefore the dot we’re pointing at on the wall is blocked by the pole Third picture, we take a picture with the camera moved one foot to the right, also pointing at the dot on the back wall. Now, if we “play” the pictures as a video in the order 1, 2, 3, frame 1: the pole will be on the right of the dot, frame 2: the pole will block the dot, frame 3: the pole will be to the left of the dot. Since we were focusing on the dot the whole time, the background will not be moving, or in other words it will already be stable, so there would be no need to stabilize the background wall. If we stabilize the the shots to the foreground (the pole), that would mean the pole would not be moving in the seen, but this would cause the background to move as follows: frame 1: the dot on the wall would be to the left of the pole, frame 2: the dot would move to the right and be blocked by the pole, frame 3 the dot would move further to the right and be to the right of the pole. In other words the wall would be moving from left to right. So, if the scene is stabilized to the background, the foreground moves and if the scene is stabilized to the foreground, the background moves. This is inherent in any scene with foreground and background objects with a moving camera that is not following a single forward facing vector. It is impossible to stabilize both the foreground and background at the same time. It is only possible to stabilize to a single depth in a scene. To add to this, there is not just a foreground and background, any chosen depth can be chosen to stabilize to. For example, if we stabilize to a depth half way between the pole and wall, then both the pole and the wall would be moving, but only half the distance of the above described scenarios. Basically, if you stabilize closer to the foreground, the more the background will be moving, and if you stabilize closer to the background, the more the foreground will be moving.

To summarize, any scene that has objects at different depths will display parallax when there is a moving camera that is not following a single forward facing vector capturing the scene. Due to the parallax, it is not possible to stabilize the scene at different depths. Therefore something in the scene will always be “shaking”.

I hope I described all this accurately and in an understandable way. Thoughts anyone? This seems like a real limitation. Is there a way to work around this issue? Am I just clearly wrong? I would love if there was a way to stabilize all depths in a scene with a moving a camera! Ever since I discovered the above through experimentation, I’ve been a bit depressed about it.


#11

You are correct, it is impossible to stabilize both the foreground and background at the same time. It is only possible to stabilize to a single depth in a scene. There are things like the warp stabilizer in Adobe products that attempt this with warping using image vectors, but they always look weird and unearthly in my opinion.