stick an layer positon on another left up corner of a square layer in After Effects I was wondering about a expression that stick a layer position on left up corner of a square solid in after effects, so that when the scale of the solid changes, the stick position follow the corner all around. Can someone help with this? Tks
The position of any point on a layer in terms of its location in the composition frame is given by the layer space transform function toComp(). Since the top left of a layer is the origin in After Effects, from the point of view of the solid its top left is going to be [0, 0]. So we find the position of the point [0, 0] on the layer in terms of the comp thus:

thisComp.layer('&lt;name of the solid&gt;').toComp([0,0])


Apply that to the position property of the layer you want to stick to the solid.