Inspired by reddit user /u/DrewFitz: Tilt brush reverse engineering. The comment from /u/1pid was also very helpful.
A .tilt file is an uncompressed .zip file with an additional header. The zip contains the following files: A thumbnail PNG, the brush stroke data in a custom binary format (data.sketch), and a JSON metadata file.
The tool can generate a new .tilt file from a json template. Only stroke color, brush size and point position is supported currently. For some reason, the generated tilt file does not behave as expected if two adjacent points in a stroke are too far from each other. For this reason, the generator will add extra points so that the maximum distance between two points is 0.5.
Wireframes can be created from .stl files.
xyz coordinates in tilt brush with reference to standard forward position (x: left to right ~[-10, 10], y: down to up ~[0, 20], z: back to forward ~[-10, 10])