Re: A Simple Motion Problem?

I get accurate results. Pal square pixel comp, square pixel solid, starting position at 1 second is 100, 288. Set keytframe, then moved to 4 seconds and set position keyframe at 1000, 288.

layer moves 900 pixels in x in 3 seconds or 300 pixels per second.

Checking position at 2 seconds it's exactly 200, 288.

Change the comp to non square pixels and the results are the same.

If you've got any easing applied or your keyframes don't look like ◊ in the timeline then you won't get exact numbers.

If you motion isn't just in x or just in y then you won't get exact numbers either. If your movement must be exactly 300 pixels per second try adding this expression to the position.

x = position[1] + (time * 300);
y = position[0];
[x, y]

this moves 300 pixels per second from left to right. Want to move from right to left then change the + to a minus. Want to move up or down, change the y to x and the x to y, then change the zero to one and the one to zero.

hope this helps....