Native document format

[slimbuck]

Fixes: #236
Related tickets: #324

This PR implements support for a native SuperSplat document.

The Scene menu has been updated to reflect document vs import/export:

Document contents

The document is a simple uncompressed zip archive containing the following files:

• document.json
• splat_0.ply
• splat_1.ply
• ...
• splat_n.ply

document.json

Contains all editor state apart from the individual splats. This includes:

• version, number starting at 0 and increasing with schema changes
• view settings
• camera settings
• camera poses
• per-splat settings.

splat_n.ply

Each PLY present in the document is similar to its exported counterpart with the following differences:

• color tinting is not applied, but rather color tint settings are stored in document.json
• the splat's world transform is not applied, but rather stored in document.json

Example

Here is a sample document.

example.super.zip

The file has been renamed to a .zip extension to allow attachment here.

Notes

• we write the document using a custom zip writer implementation in order to stream the file out and lower memory requirements
• loading the document is done with JSZip, but this likely results in memory overhead and will need to be addressed in future
• even though SuperSplat UI currently supports a single set of camera poses, the document supports multiple (since we are likely to add support for multiple in the near future).
• it would be prudent to document the schema in document.json. This will be discussed and done in a followup PR.
• we currently output the document with .super extension because I like it, but this might change based on the success or not of bribery @willeastcott

[willeastcott]

The document is a simple uncompressed zip archive

Any reason not to ZIP it? Otherwise, these things are gonna eat up quite a lot of disk space, right?

[willeastcott]

Can the menu be:

New
Open
---
Save
Save As
---
Import
Export
---
Save Screenshot

I'm not 100% sure where to put Save Screenshot actually. But grouping Import and Export would be cool (the above is more similar to Blender).

[slimbuck]

Any reason not to ZIP it? Otherwise, these things are gonna eat up quite a lot of disk space, right?

Yes. JSZip and the other libraries I looked at require a blob/array of all data before writing out the zip file. This would double the memory requirement during save. We're streaming the data out instead.

[willeastcott]

I would recommend renaming the 'Scene' menu to 'File'.

[slimbuck]

I would recommend renaming the 'Scene' menu to 'File'.

It's a big change, will do in a followup PR.