Transform.localRotation performance

I am in a situation where I have a complex machine with a number of moving axes that are governed by some external animation process. The machine is built up from rigid bodies. I need to move these axes to a certain position every frame: rotating axes for instance may be set to '45', meaning 45 degrees from its zero position.

I'm currently doing this by altering the local rotation (using localRotation instead of localEulerAngles gives me the same trouble). In the following, position is the desired rotation of the axis at the current time.

Code (csharp):

1. axis.transform.localEulerAngles = zeroposition + position * Vector3.forward;

Doing this 40 times in my scene causes the frame rate to drop from 96 to 6 fps. This surprised me. Eventually, I need to be controlling hundreds of axes.

If I would do this in OpenGL, I would simply set the transformation matrices, and then go through the model hierarchically, applying the matrices to the OpenGL transform matrices. That should not cost much time at all. Does anyone know what happens in Unity when I change the localRotation? Is there an alternative?

Any help would be greatly appreciated.

 

https://docs.unity3d.com/ScriptReference/Matrix4x4.html

That should be what you are looking for.

If you would be so kind as to show me how you would (at least in pseudo with maths) go about replicating localRotation changes.