I was looking through some old tutorial projects and came across this expression
[thisLayer.width/2, thisLayer.height/2]
which was applied to the Wipe Center property of the Radial Wipe Effect.
Basically it places the wipe center in exact center point of a layer. I thought that it had some special power like if the layer were scaled in un-equal amounts, it would prevent something funny from happening, but it works just as if the wipe center were place by hand in the center of the layer.
Then I changed it to
[thisComp.layer("flower").width/2, thisComp.layer("flower).height/2]
thinking it would cause the placement of the Wipe Center to jump to a different position, the center point of the Flower layer which was positioned off center of the composition. But it stayed right in the middle of "this layer".
So I wondering is there anything special about this expression other than figuring out the math and keeping, in this case, the property Wipe Center in the center of the layer.
I just trying to understand expressions better.
Thanks
on a mac CS 5.5