Asset compression

Verge3D supports loading of scene files compressed in the .xz file format, which incorporates the LZMA2 compression algorithm. Typical compression rates that can be achieved: 20x for the .gltf files and 6x for the .bin files.

Creating compressed files

To enable creating .xz files automatically upon export, you can simply turn on the corresponding option in the export settings.

3ds Max:


Loading .xz files

The compressed .xz files (for example, my_awesome_app.gltf.xz and my_awesome_app.bin.xz) should appear near the original ones. What is left is to enable loading them in your app. To do this, go to Puzzles and switch to the init tab:

Drag out the configure application puzzle from the Initialization category, if it is not already present in the workspace, and turn on the compressed assets checkbox on it:

Finally, click the Save button. That's it!

Checking your files

To ensure that your app now actually loads compressed assets, run your app (either from App Manager or from a website where it is deployed). Open the browser console and switch to the Network tab.

Reload your app so that the console starts displaying files from the beginning. Find the scene files in the list - if everything is ok, they should end with .xz.

The browser console can usually be opened with the F12 key (Chrome, Firefox on Windows, Linux). On Mac use the View > Developer > JavaScript Console menu (Option-Cmd-J) in Chrome, or the Develop > Show Error Console menu (Option-Cmd-C) in Safari.

Loading .xz files by Custom apps or the URL-based viewer

For Custom applications simply change var url = 'my_awesome_app.gltf'; to: var url = 'my_awesome_app.gltf.xz'; in the JavaScript code.

For Player-based applications that have a scene .gltf file specified in the URL like: http://localhost:8668/player/player.html?load=../applications/my_awesome_app/my_awesome_app.gltf you can simply replace it with the path to the compressed .gltf.xz file: http://localhost:8668/player/player.html?load=../applications/my_awesome_app/my_awesome_app.gltf.xz

The same applies to .glb and .glb.xz files if they are used instead of .gltf/.bin.

Benefits of using compression

The advantages of using scene compression in Verge3D are:

Size comparison for a sample file: raw vs GZIP-compressed vs LZMA2-compressed

Using LZMA compression is especially recommended in the following cases:

Compressing files manually or via command-line

Alternatively, you can create .xz files using archive utilities as 7-Zip, XZ Utils or others.

Verge3D implementation of an .xz decompressor puts some restrictions on compressed files due to optimization purposes, so not every .xz file can be loaded. .tar.xz files are also not supported. Considering this, it's recommended to use settings described below.


1) A popular file archiver 7-Zip can be used for creating .xz files.

To compress a file you can right click it, and then choose "7-Zip" -> "Add to arcive..." - this opens the corresponding dialog window:

The archivation settings should look like this:

The rest of options can be left by default.

Also you can use a command line version of 7-Zip instead: 7z.exe a -m0=LZMA2:d23 scene.gltf.xz scene.gltf 7z.exe a -m0=LZMA2:d23 scene.bin.xz scene.bin

2) Alternatively, you can use a special command line tool called XZ Utils. Its Windows binaries are available here in the Pre-built binaries section.

The usage is simple: xz.exe -k -f -6 scene.gltf xz.exe -k -f -6 scene.bin


1) A 7-Zip command line port can be available out of the box or from official repositories as a package named p7zip.

The usage is similar to the one in Windows: 7z a -m0=LZMA2:d23 scene.gltf.xz scene.gltf 7z a -m0=LZMA2:d23 scene.bin.xz scene.bin

2) XZ Utils is also available out of the box or from official repositories in most Linux distros.

The usage is similar to the one in Windows: xz -k -f -6 scene.gltf xz -k -f -6 scene.bin


1) A 7-Zip command line port can be installed via Homebrew as a package named p7zip: $ brew update $ brew install p7zip The usage is the same as in Linux.

2) XZ Utils binaries are available for macOS 10.5+ here in the Pre-built binaries section. The usage is the same as in Linux.