How to get the rotation data of a 3D auto-orientation layer

[Yoondo]

You need to turn off the auto orientation in order to gain control over the rotation
property of the layer.

[Dan Ebberts]

It’s not trivial. If “Layer 1” is your auto-oriented layer, this expression should give the orientation values (apply it to another layer’s orientation property):

L = thisComp.layer("Layer 1"); 
s = L.scale/100; 
u = L.toWorldVec([s[0],0,0]);  
v = L.toWorldVec([0,s[1],0]);  
w = L.toWorldVec([0,0,s[2]]); 
sinb = clamp(w[0],-1,1);  
 b = Math.asin(sinb/thisComp.pixelAspect);  
cosb = Math.cos(b);  
if (Math.abs(cosb) > .0005){  
  c = -Math.atan2(v[0],u[0]);  
  a = -Math.atan2(w[1],w[2]);  
}else{  
  a = Math.atan2(u[1],v[1]);  
  c = 0;  
}  
[radiansToDegrees(a),radiansToDegrees(b),radiansToDegrees(c)]

Dan

[Gthief]

thanks Dan, i’m not good in writing expression, can you tell me how it work?

[Dan Ebberts]

It’s all 3D vector math and rotation matrix transforms. Easier to use than to explain. 🙂

Dan

[Gthief]

🙂 ok, thanks again.