Rotating a Lighting Device on 3 Axis.

[isyme]

Hi there,

 

I have a custom lighting device representing a projector that I wish to rotate on all 3 axis. 90 on X, 90 on Y, and around -15 on the Z. 

 

When I go for the final Z rotation in the OIP - it add's the angle on to the X rotation - not the Z. Attached are some pictures showing the steps. 

 

 

Has anyone come across this before and been able to solve it?

 

[JBenghiat]

The rotation values are really a single transformation rather than sequential transformations in the order you apply them. The two sets of transformations are effectively the same, so Vectorworks recalculates to the simpler of the two. 

[isyme]

That is what I feared, effectively the same ... but not quite the same. Thanks Josh!

[JBenghiat]

Keep in mind that pan and tilt are on top of this rotation. The x, y, z rotation values just set the reference orientation. Also, while the order that you enter rotation values doesn't matter, the lighting device will always apply in the order of z, x, y, so when a lighting device is yoked out at 90 degrees, the z and y rotations have the exact same effect.

 

Think in terms of first setting the plan orientation of the fixture, and then either pivoting the clamp on the pipe to yoke it up/out (x axis) or pivoting the pipe (y axis).

 

Do get the rotation you're after, either apply a 15 degree tilt after rotating ( 90, 90, 0 ), or first set your z rotation so that the yoke is parallel to the way you want the lighting device to point, and then set a 90 degree y rotation.

 

Of course if this is a projector, it doesn't necessarily have a clamp and a yoke, so there may be a larger discussion of how to specify the orientation.