How to use BILLBOARDMODE_Z?

[Evgeni_Popov]

@JacobF

Is this the least expensive way to get this result, though?

It seems fine to me. You can use FromLookDirectionRHToRef instead of FromLookDirectionRH to avoid some GC.

@JacobF

Also, it still bahaves slightly different when looking down from its top, the blue one spins around a little crazy, while the yellow one is stable when looking down from the top.

I did not reproduce with your PG, but I think it’s the gimbal lock problem. The best way to avoid it is to not allow the camera looking straight down (set constraints on camera.beta).