Camera initializing problem in loading_model.py

[houkensjtu]

Hi,

The camera initialization in examples/loading_model.py doesn't seem right:

camera = t3.Camera(taa=True)

https://github.com/taichi-dev/taichi_three/blob/4e46f9d840c4055b5eae91375b74a7632fc46544/examples/loading_model.py#L10

I've tried to remove the taa option and it worked just fine.