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particular ring
In Andrew Kramers last tutorial He gave us an expression (Preset 3d orbit) that makes particular form a ring. Pretty cool I say.no need for motion path. What would one have to do to make the ring stand up like an O with out use of a camera position and position it anywhere in the frame not just the center. any thoughts? FYI working on a project where after two or three revolution my O turns into an arrow and shoot up a graph. Any thing will be helpful. I know I probably have to make a motion path. Wanted to know if there was anyway to tweak the expression. if not sure what I am talking about check out his last totorial on videocopilot.com
David
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2 Replies
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I’m not sure what the whole set up was, but the basic expression for a circle is:
angle = degreesToRadians(45);x = Math.cos(Math.PI * 2 * angle);
y = Math.sin(Math.PI * 2 * angle);[x,y]
Andrew probably adapted the 2D circle into other dimensions. For example, changing the last line to:
[x,y,0]Would give you a constant Z value of 0, so the circle would lie on the XY plane.
[x,0,y]Would give you a constant Y value of 0, so the circle would lie on the XZ plane.
However, I think an easier solution would be to parent the emitter (if its a light or a null object) to a Null object and rotate that around whatever axis you want. If you’re using a null object then this would require the expression applied to the Particular emitter expression to be improved. For the X & Y coordinates:
l = thisComp.layer("Emitter");
x = l.toWorld(l.anchorPoint)[0];
y = l.toWorld(l.anchorPoint)[1];
[x,y]
And for the Z coordinate:
l = thisComp.layer("Emitter");
l.toWorld(l.anchorPoint)[2];
Darby Edelen
Designer
Left Coast Digital
Santa Cruz, CA -
Cool. Thanks so much! expression are great, just need to get my head around them
big help
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