LookAtConstraint rotation affected by worldUpObject's position and not rotation?

[daniel_lochner]

Hi there,

I’ve assigned a transform to the worldUpObject field of a LookAtConstraint component as shown below:

Why is it that changing the position the worldUpObject in relation to the object on which this constraint is attached, affects its rotation? Should it not just depend on the rotation of the worldUpObject? Rotating the worldUpObject actually doesn’t seem to affect the rotation at all, so am I misunderstanding something?

Thanks,
Daniel

[SVAFnemesis]

“World Up Object” really means “Y Up Object”. They put in the wrong name here.
Y Up Object defines where constrained object’s y axis is pointing towards after constrained object’s Z axis has locked to the “source”. And because of that, Y Up Object’s rotation has no effect, only position in relation to the constrained object matters.

[daniel_lochner]

Thanks for your response @SVAFnemesis !

@SVAFnemesis

“World Up Object” really means “Y Up Object”. They put in the wrong name here.

From my understanding, the worldUpObject used for the LookAtConstraint is similar to the worldUp used in the LookAt method of the Transform component.

@SVAFnemesis

Y Up Object defines where constrained object’s y axis is pointing towards after constrained object’s Z axis has locked to the “source”.

Yes, I agree that is how it should work. The documentation for LookAt describes it like this: “Then it rotates the transform to point its up direction vector in the direction hinted at by the worldUp vector. If you leave out the worldUp parameter, the function will use the world y axis.”

@SVAFnemesis

And because of that, Y Up Object’s rotation has no effect, only position in relation to the constrained object matters.

Not quite sure why this would imply the worldUpObject rotation not to have an effect on the source’s rotation though? The LookAt works as expected, where the the position doesn’t affect it at all.

[daniel_lochner]

Bump