expression for reducing values?

[grahamdunn]

I have a sky parented to a track of a foreground object. The sky is in 3D space, and moves way too much due to the foreground track being up front. I need to keep the motion of the sky the same but just reduce the amount it moves overall so the paralax looks right. I know there has to be an expression (something like linear(value0,100, 0, new lower value)) to remap one set of values to another, in this case to lower the position values to something less extreme. Any ideas? Thanks!

 

[triplej96]

I believe your problem lies in your track point. For tracking a sky try and track a object as close to the horizon as possible not a foreground object. Doubtful the sky needs to be in 3d space depending on the shot. Also it a may need a 3d matchmove solution not a 2d track depends on the shot.

Hope some of that helped.

 

[grahamdunn]

You're right in general, but in this case all I have is a sign in the foreground, there is only totally plain sky filling the rest of the frame. I'm replacing it, and have tracked and rotoed the sign in Mocha. I applied the position data to a large still plate of a cloudy sky, set in 3D to keep some hint of parallax. Typically you'd track mountains in the distance or something, but in this special case I have no detail whatsoever but the immediate foreground. It's a quick shot so it'll probably be okay, but I'd like to reduce the strength of the motion while keeping the gist of it intact if anyone knows a way...