| **Movement from a Parented layer to 3d stroke**
on Apr 9, 2018 at 7:44:53 pm |

Hi Guys,

I have a 3d layer which is parented to a 3d null which is animated along position and rotation. Basically, 3d Layer is a Mobile Comp. I also have a layer which has a 3d stroke effect on it. I have already added toWorld expression to the position of xy and z in the effect which traces back the world position of the mobile. When I add below expression to the rotation it works fine but gets crazy when I add a value to it at the end.

For rotation in x

L = thisComp.layer("Child Layer");

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;

}

x=radiansToDegrees(a);

For rotation in y

L = thisComp.layer("Child Layer");

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;

}

y=radiansToDegrees(b);

For rotation in z

L = thisComp.layer("Child Layer");

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;

}

z=radiansToDegrees(c);

So by adding these expressions, I get my 3d stroke parallel to the mobile so to work it as a speed line rotating around I need to add 90 to the end value of x rotation or in y..here it becomes crazy and that's where I need some expression help

Is there any other way to solve this problem...?

| **Re: Movement from a Parented layer to 3d stroke** on Apr 13, 2018 at 5:56:15 pm |

Any chance of getting an image of what you currently have and what you want to change in it? My abstract conceptual inclination is to suggest a child null or layer rotated to the position you want, but I don't really have a clear picture of what the exact issue is.

Kalleheikki Kannisto

Senior Graphic Designer