.bin-file and effect of the xz-compression

Hi,

Reducing files size is especially noticeable on slow connections. On a fast network, or when viewing from localhost it can look almost the same. Besides compressing .gltf/.bin files, one should also take care of images especially if a project loads many high-res textures. Here are some recommended practices:

• Prefer JPEGs over PNGs if you don’t need transparency
• Consider lossy/lossless compression when possible
• Use normal editing instead normal maps, vertex colors instead diffuse textures

3dmdlb wrote:

What is in the .bin-file and what effect has the xz-compression on it?

glTF, Verge3D’s main file format, consists of textual (.gltf) and binary (.bin) parts. The textual part describes the scene graph and references model data in the binary file. The binary part contains geometry (positions, normals, UVs, etc) and animation data. Here is Khronos’ chart illustrating that:

The LZMA (.xz) compression just reduces the size of the .bin file (similar to zip or rar archives). It is more efficient compared to standard gzip compression available in browsers and unpacking it is fast.