I tried running the code a few times and I noticed it doesn't allways end up at the same angle. I don't understand how captureworld and renderworld tween work, so I have trouble understanding what your code does exactly, but I think it doesn't complete the 1000 ms timeperiod exactly enough.
There is deltatiming, but I think you know that. You could rotate something 180 deg/sec like this:
RotateEntity mesh, 0, Millisecs() * 180 / 1000, 0
There is deltatiming, but I think you know that. You could rotate something 180 deg/sec like this:
RotateEntity mesh, 0, Millisecs() * 180 / 1000, 0