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Draco Compression support is here

Jens Fursund
Jens Fursund
, updated Sep 7, 2023
You can now convert GLB and GLTF files that use Google's Draco compression format

If you've received a GLB or GLTF file for an AR or VR project, there's a chance its geometry and other contents are compressed. And if that's the case, you may not be able to open the file in some apps or converters.

Today, we're launching fully automatic Draco decompression when you convert a GLB or GLTF to e.g. OBJ or FBX.

What is Draco compression?

Draco is a compression method invented and open-sourced by Google's Chrome Media Team. It compresses a 3D model's meshes, point clouds, and other features. This is useful for apps and web applications because it speeds up download time without reducing the visual quality of the model. It also takes up less disk space, typically making them half the size, and up to 95% in many cases.

How do I convert a Draco-compressed model to other formats?

The easy way: In Convert3D, you don't have to do anything when you convert your models. We take care of the checking, validation, and decompression before converting your model to other formats, like GLB to OBJ.

The manual way: If you prefer to do things manually and in code, take a look at e.g. the glTF Transform library for Node. You'll also need the draco3dgltf NPM package.

The automated way: Convert3Ds API (currently in closed beta) also supports Draco decompression out of the box.

How do I convert a model to glTF with Draco?

First, convert your model to glTF using e.g. Assimp or an online converter like Convert3D (see all formats), then use the glTF Transform library.

Convert3D may support Draco for compression in the future when you choose GLB or glTF as your destination format. If you're interested in trying this out, email us at hello@convert3d.org.

A few things to keep in mind

Your final file size depends on the model. If there's a lot of geometry - say, more than 1MB - Draco for glTF is really effective and can turn a 1Gb file into a 50MB file in many cases! If you have a lot of animations or large textures, Draco can't help, and you should consider looking into other compression methods for those parts.

Draco compression is not lossless. While you may not see any visual changes after compressing your model, make sure to keep the original around.

Draco is for uploading and downloading only. It decompresses before the model is sent to the GPU, so the number of vertices when rendering the model stays the same. If your model is sluggish in use, you should consider simplifying your geometry, too.

Read more

Draco 3D data compression website

Draco and glTF

glTF website

Khronos glTF transform Draco extension

Convert 3D