Automation Blocks 3d Stabilized Pre-Comp

[PFuerst]

Hey,

I was jsut watching this tutorial which uses a pretty clever technique to create a stabilized pre-comp from a 3d track. https://www.provideocoalition.com/after-effects-syntheyes-for-advanced-screen-replacements/

I was wondering if this can be automated using Automation Blocks. It probably can be done but this might be (way) above of what I might be able to "code" with it.

Maybe someone (Mathias ;-)) can help here.

Best regards

[Mathias Moehl · Accepted solution]

Cool idea, Pascal! I created the following two tools for you:

1) Create 2D Position Nulls for All Selected 3D Layers.xml

2) Create Power Pin Stabilized Precomp from 4 Corner Nulls.xml

they are both in the Community Library now, too.

Usage:

Select the four 3d null layers you obtain from your tracker for the 4 corners of the precomp, then run the first tool. It will create for each of the 3d nulls a corresponding 2d null with the same position (using the toComp expression).

Then select the four 2D nulls you just created and also select the footage layer and run the second tool. It will replace the footage layer by a stabilized precomp using CC Power Pin effects. The corners of the stabilized precomp will be linked to the 2D null layers.

Things to be aware of:

- When running the second script, make sure to select the null layers in the same order as the corners are listed in the CC Power Pin effect, i.e. Top Left, Top Right, Bottom Left, Bottom Right

- make sure all layers and comps have unique names. If all nulls have the same name, the expressions are not able to find the right layer

PS: Next week I have a session at the Video Creators Virtual Summit about Automation Blocks for Ae. This will be a good opportunity to learn more about the tool and it is free to attend (but requires registration).

[PFuerst]

Hey Mathias,

that is amazing. You are incredible fast with AB. 8)

Will test it tomorrow. Is it also possible to adjust those 2d Nulls or the power pin if the stabilized area needs any further tweaking?

PS: Next week I have a session at the Video Creators Virtual Summit about Automation Blocks for Ae. This will be a good opportunity to learn more about the tool and it is free to attend (but requires registration).
By @Mathias Moehl

Cool. I will check it out 👍

[Mathias Moehl]

Yes, the key point of Automation Blocks is that developing the tools can be so quickly 🙂

Good point with the offsets! I just updated the "Create 2D Position Nulls for All Selected 3D Layers.xml" such that it

- sets the position value of the 2D null to [0,0] and

- uses this position value as offset to the position of the 3D value.

That means, you can keyframe the 2d null now to add corrections on top of the track (similar to what you can do with MochaImport+; https://www.youtube.com/watch?v=dnTej-HDWrk)

[PFuerst]

Wow cool. Mocha Import+ is such an amazing tool and I use it all the time when working with Mocha and AFX.

I just wish it would also take care of setting up a Mesh Tracking workflow 😉

I just tested yesterdays version and it seems to work great.

In the shot the camera was passing by(flying over) the nulls which caused it to "freak out". I guess this has to do with the corner pin effect and maybe the nulls crossing over each other(it was not a perfect shot for this in general but it was one I had at hand). Is there something that can be done in such a case? Or is this a limitation of the corner pin effect?

[Mathias Moehl]

Not sure what exactly the issue is. Are the 3D nulls moving with the footage correctly? In general, when the corner pin corners move in strange ways (say swap position, for example) then the results can in deed look strange.

[PFuerst]

I think it happens when one or more of the corner points reach the limit of the workspace(way outside the viewer) of afx which might happen with extreme focal length or extreme long shots.

I guess in most cases all those corners are already outside the frame before any strange clithes happen or it would be better to use a different approach in the first place.

As a side note: I also noticed that it is best to pre-render any footage(in an undistort/re-distort workflow) with undistortion fx applied to them as with those fx on the footage they wouldn't line up with the plate properly.