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Maya Locator Animation Data to AE Corner Pin
Hey, I have to do a screen replacement for a homework assignment. I modeled a cell phone in Maya and want to place a motion graphics video onto the screen. But I need help parenting my video onto the phone screen. This is what I did:
I parent constrained a locator to each of the four corners of the phone screen. Then I baked the animation and camera using the rcExport2AE script that exports camera and object position data to after effects. It saves as both .jsx and .ma files.
Then I ran the .jsx file and opened the composition. The comp has the four locators, which after effects recognizes as nulls, and the maya camera. The movement looks great.
Now here is where I get lost.
I thought I could apply the corner pin effect onto my video, then alt+click the stop watch and pick-whip each corner pin to the position of my nulls. Note: the nulls are 3d layers. I made the video a 3d layer, too.
Anyway, the pins don’t stick in the right position. Sometimes you can’t see the video. It disappears once the pick-whip is done.
Am I missing something or was my process completely wrong? I would really appreciate any help. I scoured the internet all day and haven’t found the advice I’m looking for. Thanks in advance!
I’m using Maya 2016 (but I’m familiar with 2015, too) and After Effects CC 2015.
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2 Replies
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[Diana Jordan] “Am I missing something or was my process completely wrong? I would really appreciate any help. I scoured the internet all day and haven’t found the advice I’m looking for. Thanks in advance!”
Generally if you have 3D locators and a 3D camera that matches your scene I’d recommend parenting the 3D screen footage layer to one of the 3D locators to get it in the right spot. If you choose to parent to the upper left screen corner locator then you could set the anchor point on the 3D screen footage layer to the upper left before parenting. If you hold shift while parenting the 3D layer’s anchor point will snap to the 3D locator’s anchor point. From there it’d just be a matter of rotating the footage into place if necessary (sometimes a 90° flip on an axis or two, or a 180° flip).
[Diana Jordan] “Anyway, the pins don’t stick in the right position. Sometimes you can’t see the video. It disappears once the pick-whip is done.
“If you’re set on using the corner pin effect then you need to translate the 3D coordinates into 2D composition coordinates using an expression. In this case your footage layer should not be 3D; the camera projection + corner pin would double up on the perspective distortion and cause all kinds of whackiness.
The expression to convert 3D coordinates to 2D takes this form:
layer = thisComp.layer("Locator_01");
layer.toComp(layer.anchorPoint);Where “Locator_01” is the name of the 3D layer. This returns the 2D projection of the 3D point in composition coordinates. You would apply this expression to the corner pin property that you want to line up to Locator_01.
Darby Edelen
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Thank you for replying!
I tried parenting a solid to the phone by holding down shift and pick-whipping a null. Then making that solid a 3D layer. I scaled and rotated the solid to fit the screen, but it won’t stick. The phone is animated; it’s rotating from the left to the center. I think I neglected to mention that it’s the screen I’m trying to matchmove.
I also tried the expression, but I think I got that wrong. I pasted the expression in the corner pin’s “upper left” property and typed in the name of the null in place of “locator.01”. The solid disappears from view as a 2D layer, but appears when it’s a 3D layer. Also, the points don’t stick in place.
I’m not sure what to do. I thought I could track with maya by baking locators for cases like this.
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