Camera analysis adapt to Timewarp

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1

Hi folks,
we currently have to retouch timewarp artifacts and unfortunately the camera analysis does not work at all on the timewarp. It works great on the untimewarped plate, is it possible to adapt the tracking data to the timewarp? Unfortunately I have not yet found a way to do this.

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An eval expression on a copy of the tracked camera might work:

eval(tracked camera, timewarp frame)

But Iā€™m just marking a guess till someone else pops in with a real answer.

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3

Somebody explained this to me a long time ago and it did work, but alas my brain has since decided I do not need to remember it. Luckily I wrote myself an email at the time explaining.
Alas, reading it back I cannot remember much about it/doing it, so if you have any questions I am probably not your manā€¦ Hope it helps.

Once you have your camera and geo working, decide on the timewarp for the shot and build a TW node. Name it TW

In the action schematic, name your main camera, CAM1. Duplicate this and name it CAMTW.

Feed the TW node into the back of your action that has the camera.

Now go to the animation window. Scroll down until you find CAM_TW

Select this, and then hit the right bracket key ]

This should bring up the expression bar.

Type in eval(CAM1,TW.Timing)

CAM1 = Original camera
TW = TW node feeding into back of action
Timing = The timing parameter in the animation menu of the TW node.

This should now place an ā€˜eā€™ next to the CAM_TW in the animation menu.

All thatā€™s left to do now is go back to the schematic and choose then new camera to view through, ie. CAM_TW

*If you want to project something, you would normally copy the camera, and on the ref frame, hit keep and only that keyframe would remain. When you do an expression to link to the timewarp node, it removes all individual keyframes and has a curve set in stone. *

So, copy the new camera(CAM_TW), go to the animation menu, select copied camera and uncollapse everything in it , and then on the right hit ā€˜bakeā€™. This will give you individual points, so you can now ā€˜keepā€™ the ref frame you want.

Also, make sure your timearp node is on motion, or feed in an ML timewarped clip into the background, and have the timewarp node outside of action to link your expression to.

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4

This is the way. Youā€™ll need to rebuild the tw as a timing tw rather than speed, then use the timing keyframes to drive the eval. Should work great.

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Not sure what version you have , but (I havenā€™t tried this with camera tracking) you might try using MLTW first then track that. Iā€™ve had ok results doing this with traditional tracking.

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You should be able to do this as it can be done with normal tracking data I donā€™t of the bat see why it wouldnā€™t apply to a camera in action.

I have it written down somewhere but Iā€™m out and about today.

The great @john-geehreng haha, would be the one to ask as heā€™s where I got the expression from back in the day.

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7

Iā€™ve always used the expression that Andy and Grant shared.

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8

Iā€™ve had great results using MLTW to slow it right down, before applying your respeed curve.

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Also the Flame Planar Tracker does not understand timewarped footage most of the times. Also when there are black bars as letterbox, it thinks that is part of the footage.