What I'm trying to achieve is a water spray effect, so I use some sort of paint stroke.
After that I apply the filter "bump map" to the footage and assign the brush stroke as the source. Of course I turn off the brush stroke, because I want that liquid-y effect and not a white paint stroke.
The problem is, that the bump map doesn't correspond to the position of my paint stroke - meaning - it is as if always centered in the image, when instead, the paint stroke is for example in the top right position of the image. And the scale isn't correct as well.
I thought I was onto something, and maybe I am, when I realized that the paint stroke's canvas is not the entire canvas, but only whatever creates itself in its own little "space". - I don't know if you understand. My english is not the best I know. The bump map filter acts as if the brush stroke's "canvas" is the whole image.
This is the movie that I'm making:
the water spray effect were hours of wrestling with Motion, and I still don't know the solution to my problem.
Can anyone help please? It would be greatly appreciated, and it would surely help the movie to look a lot better than it does, because I'm not as satisfied with it as I would want to be.
I happen to be working on a video tutorial for Motion 3 and 4 that addresses this problem. The bump map filter only effects the area where the water paint stroke is. So the work around is to place the water effect in a group so it feels the whole screen. Be sure to check the fixed resolution check box in the Group tab (F4). Then apply the group to the bump map source well and it will do the trick. Best of luck.