[Dan Ebberts]

I haven’t tried it, but it seems like you’d want to use Math.floor() instead of Math.round() to avoid an out-of-range index.

Dan

[Dan Ebberts]

I haven’t tried it, but it seems like you’d want to use Math.floor() instead of Math.round() to avoid an out-of-range index.

Dan

[Dan Ebberts]

For your “shadow catcher” layer, use a white solid, set its mode to Multiply, Accepts Shadows = On, Accepts Lights = Off.

Dan

[Dan Ebberts]

I would think something like this should work (but I haven’t tested it):

currentFrame = timeToFrames();
value – [currentFrame*1.4,0]

Dan

[Dan Ebberts]

I would think something like this should work (but I haven’t tested it):

currentFrame = timeToFrames();
value – [currentFrame*1.4,0]

Dan

[Dan Ebberts]

You’ve got things in the wrong order for your y definition. It should be more like this:

y=thisComp.layer(“Null 6”).transform.position.valueAtTime(t-1)[1]+34;

Is what you posted the entire expression? If so, you’ll need to define “t” to get it to work (or use “time”).

Dan

[Dan Ebberts]

You’ve got things in the wrong order for your y definition. It should be more like this:

y=thisComp.layer(“Null 6”).transform.position.valueAtTime(t-1)[1]+34;

Is what you posted the entire expression? If so, you’ll need to define “t” to get it to work (or use “time”).

Dan

[Dan Ebberts]

You run into that sometimes when you mess with the time component of an expression. What happens is, that at each frame the expression calculates its result as if the frequency had been at the current value since time zero. It doesn’t remember that it was at some other value on previous frames. So there’s this discontinuity. It takes more work to get it to act like you’d expect. For example, you could go frame-by-frame and calculate the accumulated angle at the current frame.

Dan

[Dan Ebberts]

You run into that sometimes when you mess with the time component of an expression. What happens is, that at each frame the expression calculates its result as if the frequency had been at the current value since time zero. It doesn’t remember that it was at some other value on previous frames. So there’s this discontinuity. It takes more work to get it to act like you’d expect. For example, you could go frame-by-frame and calculate the accumulated angle at the current frame.

Dan

[Dan Ebberts]

Yes, value is the key. As an example, this expression will cause a layer to orbit its keyframed position:

r = 50; //radius (in pixels)
f = 1; //orbits per second

angle = time*Math.PI*2*f;
value + [Math.sin(angle)*r, -Math.cos(angle)*r]

The important point is that whatever you add to value needs to be a 2-dimensional quantity. Normally it will be in the form

value + [a,b]

where ‘a’ will get added to the layer’s x position and ‘b’ will get added to the layer’s y position.

Hope that helps.

Dan