Moho Forum

HI I am having a problem working out masking and was wondering if anyone can shed a light on it. I will try my best to explain my problem.
I am trying to animate a cross as though it was drawn on a blackboard. But it is floating in mid air and i want it to appear as though it is drawn in mid air.
The problem i have is the background isnt one solid colour but a png of some curtains. I therefore cant just draw two boxes and animate the box to reveal the cross.

I was hoping to use masking but cant figure out what the configuration should be to have the box invisible but when i animate it it reveals the cross i have drawn
underneath. I hope i explained my conundrum properly.

Any help would really be appreciated.

This "works", but is it what you want?

Group: masking: reveal all
> vector: one arm of your cross: mask this layer
> vector: the moving mask for the above arm - this overlaps the arm of the cross: subtract from mask
> vector: the other arm of your cross: mask this layer
> vector: the moving mask for the above arm - this overlaps the whole of the second arm of the cross: subtract from mask
Outside this group: your background

frame (e.g.) 20: select all the points in mask 1 and move the shape in the direction of the stroke to be clear of the arm of the cross
frame (e.g.) 25: select all the points in mask 2 and reset all points
frame (e.g.) 45: (as 1) move mask 2 to be clear of the other arm


there are other ways to do this .. depends on how you've drawn your cross - e.g. does it have to be on one vector layer? is it just two strokes (i.e. not a filled vector)? Do you use a shadow to make it look as though it's floating? Is there a hand moving to draw it?