Could You Provide Detailed Insights on the Uniform TSDF Utilized in the UniformTSDFVolume Class?

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [X] For Python issues, I have tested with the [latest development wheel](https://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](https://www.open3d.org/docs/release/) and the [latest documentation](https://www.open3d.org/docs/latest/) (for `main` branch).

### My Question

Hi, thanks for your excellent and convenient work!

Recently, I have encountered some confusion while using the UniformTSDFVolume, and there seems to be limited information available online.

Specifically, I am puzzled about the meaning of the values in the uniform TSDF. I understand that a value of 0.5 represents the surface. However, does a value greater than 0.5 indicate the outside or inside of an object? If a value greater than 0.5 represents the outside, why do the values of outside voxels beyond the truncated distance become 0 instead of 1? As we know, in vanilla TSDF, 1 indicates the truncated value on the outside, and -1 indicates it on the inside.

I look forward to your reply, as it will help me a lot