Distortion Tracking question

Hi,
Suppose I have completed Distortion Calibrate in Mocha Pro, do I need to export them as sequence or mov, and then tracking?
or is it possible to tracking in Mocha Pro after completing the Distortion Calibrate?

thank you.

Once you have completed a lens calibration, you can track and roto with the distortion in place. You’d see the overlays distort with your calibration. You only need to render if you plan to get rid of the distortion permanently.
You will need to utilize the undistort and distort workflows to make sure the results remain consistent in other applications, however.
This depends on what target compositing application you’re going to. For example, in Nuke, you may want to render out an STMap from the Mocha lens module to warp the source plate using Nuke’s STMap node, or alternatively render the undistort directly from the Mocha Pro plugin.

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Hi, thanks for replying.
I noticed that the Surface is calibrated, but when I click Track, the preview still shows the original, distorted video.
I want to use Camera Solve after distortion calibrate, will it affect my tracking? cause the preview still looks distorted.

thank you.

@da00oha
Yes, the preview should continue look distorted. But Camera Solver will take in count that calibration data you did in previous step.

In case you would preffer to work with “undistorted look”, you should follow the workflow Martin explained earlier. I recently made a tutorial showing that pipeline, try to google " Why to use STMaps? Undistorting with Mocha Pro" if you need a step by step lesson.

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Hi, I have watched your videos and subscribed :slight_smile:
generally, I also use STMaps in Nuke, or use Mocha in AE to apply STMaps.
Just found that when I finished the Distortion calibration, and then Tracking, the preview would change back to the original, not the calibrated one, so I had doubts.
No problem now, thank you all. :pleading_face::pleading_face:

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Oh, I saw this blue dotted line, the calibrate was applied correctly. My bad :persevere::persevere:

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Hi, i don’t know if this is the correct way to put a question but i don’t wanted to create another topic.
I wanted to track a random youtube video where an amazon van drives down the street and is captured by a security cam in the frontyard. The truck in question had a lot of reflection and there was also some lens distortion. There was no possible way to track the truck and I thought it was because of the high reflection until I calibrated the lens out of curiosity and everything changed. Is calibration a way to get better tracking?

Hello @JohnSundayBC

Standard vfx pipeline requires to undistort the footage as a first step.

You mentioning that you footage is from security cam. Such cameras has either very wide or fisheye lens, meaning that there’s definitely distortion happening. So you wouldn’t be able to get a good track before you calibrate the lens first.

However, if you would work with the footage that was filmed with more narrow lens, often undistortion step could be skipped. Meaning, for planar tracking with Mocha that’s not always necessary. We recommend trying to calibrate the lens when you start experiencing troubles with tracking & tracked object is close to the frame edge, or when there’s visually noticable distortion presence in the shot.

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Thanks for replying…now I know why I couldn’t even track a pixel in that shot.

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Hi, me again, it may be something basic but I do the calibration and when I render the distortion is removed but part of the video at the ends along with the van is cut off and with a little zoom. I suppose that mocha does the tracking on the undistorted video even though the video is being displayed without calibrating in the track module because the shape goes crazy right in the part where the truck disappears from the frame in the already calibrated video but visible in the current layer of the track module so it is impossible for me to complete the tracking. is this a coincidence or does mocha really do the tracking on the calibrated video?

Hi
Yes, mocha takes in count calibration, even if you still see the distortion in the track Tab. We touched this a little bit earlier in this thread, Martin did pretty good explanation of the process