The difference of Stable-Zero123 and Zero-123-XL

Hi

Thanks for your excellent work.

I am wondering the slight difference in your stable_zero123_guidance.py and zero123_guidence.py.
Could you please explain why the delta radius is different from zero123?
``` python
T = torch.stack(
[
torch.deg2rad(
(90 - elevation) - (90 - self.cfg.cond_elevation_deg)
), # Zero123 polar is 90-elevation
torch.sin(torch.deg2rad(azimuth - self.cfg.cond_azimuth_deg)),
torch.cos(torch.deg2rad(azimuth - self.cfg.cond_azimuth_deg)),
torch.deg2rad(
90 - torch.full_like(elevation, self.cfg.cond_elevation_deg)
),
],
dim=-1,
)[:, None, :].to(self.device)```