Why Translation normalization have a huge impact on the rendering result?

[Miaosheng1]

Hi, I'm training the Mvsplat to reconstruct the street scene, and I find a question:

• when i normalize the extrinsics (eg. translation ) using the following code, i can get a good result ( orange curve)。 scale_factor /= np.max(np.abs(wordl2camera[:, :3, 3])) wordl2camera[:, :3, 3] *= scale_factor
• when i comment out the normalize code, the training PSNR has decreased significantly ( blue curve)。

The comparison curve of training process is as follows:

Can you provide some explanation for the phenomenon？

Normalize the translation Render Depth:

Unnormalize the translation Render Depth:

Corresponding Image: