Add CenterOfGravity

[petrvanekrobe]

No description provided.

[moritzstaffel]

As fixtures can have rotating parts that also change the the COG, I think it would be beneficial when the this is defined in the geometry. So every geometry can have their own weight and their own COG, so that you actually can do a precise calculation with it.

[petrvanekrobe]

We have considered this, but given that there are further implications (further large inner parts, like heavy lenses, moving, shifting the COG for the geometry), we have decided to clarify that this applies to devices without moving parts.

[moritzstaffel]

Yes for sure, but when you have the weight in the geometry, you could also set this up, then you can move the lens with a weight.
Just adding a global center of gravity does not allow this.

In Production Assist we have added this feature, and compared the results the the way how you define it. For some fixtures we saw differences up to 30% in the inertia for dynamic calculation.

[petrvanekrobe]

Our original intention was to support this for Speakers, where the global center is sufficient, easy to understand and utilize. Adding it to each geometry would be adding higher precision data (pro) which is more complex (con). What do you @moritzstaffel need for the calculation, weight and CoG for each geometry? The CoG would be vec3 as an offset from the geometry origin point? Anything else?