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layer always facing the ground

Posted: August 19th, 2010, 11:07 am
by manumanu73
Hi, i need a little help on i guess a simple expression,
how can i make a 3d layer always being parallel to the ground iven if that layer is parented to another 3d layer wich is rotating in x and z .
thanks for your kind help.
M

Re: layer always facing the ground

Posted: August 19th, 2010, 11:25 am
by Dan Ebberts
I'm sure there's a way to do it with 3D rotation matrices, but it's probably messy. Do you really need it to be parented to the other layer? How about if you had a position expression that always keeps the layer at the same relative position. Even easier, possibly, would be to parent a null to the rotating layer, then just have your flat layer track the null's position without being affected by the rotation of the parent?

Dan

Re: layer always facing the ground

Posted: August 19th, 2010, 1:33 pm
by manumanu73
Thanks for your reply i have tryed your solution, linking the parented nul object with to the position of my layer but when theire is a movement my layer dont even move with the my setup??!!..
an other solution would be for my to keep parallel to layer creating a nul object out of my chain but i dont know how i could write that expression. if any body knows how to
M

Re: layer always facing the ground

Posted: August 19th, 2010, 4:59 pm
by Dan Ebberts
>when theire is a movement my layer dont even move with the my setup

The expression linking the non-rotating layer to the null's position should look like this:

Code: Select all

L = thisComp.layer("Null 1");
L.toWorld(L.anchorPoint)

Dan