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orient one partended layer towards another parented layer
i dug deep in the various forums to find something that helps. I did find this expression, but this only works for non parented layers:
delta = position – thisComp.layer(“Null 1”).position;
radians_to_degrees(Math.atan2(delta[1],delta[0])) + 90I tried to incorporate this expression (which gets world coordinates of parented layers)
L = thisComp.layer(“Null 1”);
L.toWorld(L.anchorPoint)but I was not get something working, because heck, i hardly have any expreience in writing expresions myself.
Can one of you expression masterminds solve this?
regards
Neil—
Neil Stubbings
Graphic Design | Motion Graphics
https://www.stubbings.ch
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5 Replies
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Try this:
L = thisComp.layer(“other parented layer”);
v1 = normalize(L.toWorld(L.anchorPoint) – toWorld(anchorPoint));
v2 = toWorldVec([1,0,0]);-radiansToDegrees(Math.acos(dot(v1,v2)));
You might have to add or subtract 90 degrees or add 180 degrees to get it to point in the right direction, depending on how you have things set up
Dan
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oh man thanks alot dan, your wizardness is amazing!
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Neil Stubbings
Graphic Design | Motion Graphics
https://www.stubbings.ch
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hmm, gives me an invalid numeric result (divide by zero) on line 5
any ideas?
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Neil Stubbings
Graphic Design | Motion Graphics
https://www.stubbings.ch
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The only way I can think of that happening is if you let both layers occupy the same position, where the notion of one layer pointing at the other really has no meaning. This should defend against the error, but you may get bizzare results if you let the layers line up like that.
L = thisComp.layer(“other parented layer”);
v1 = L.toWorld(L.anchorPoint) – toWorld(anchorPoint);
if (length(v1) < .0001){ value }else{ v2 = toWorldVec([1,0,0]); -radiansToDegrees(Math.acos(dot(normalize(v1),v2))); } Dan -
In case anybody runs across this in the future and you find that your layer doesn’t quite follow where it’s supposed to; it may have to do with numbers of rotation degrees running into and out of the negative numbers. (I think…that’s what mine appeared to be doing.)
Simply put a positive number on the actual rotation value of your layer (I did 90) then subtract it in the expression. Life is now golden.BTW, Dan, you saved me much heartache and brainache with this one.
– The Great Szalam
(The ‘Great’ stands for ‘Not So Great, in fact, Extremely Humble’)No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.
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