A generated or scanned character can look ready to use in a 3D preview, but getting it into VRChat takes a few more steps. You may need to convert the file, reduce its size, add a skeleton and check its scale in Unity. Here's a practical route from a GLB file to an upload-ready avatar.
Many generators and scanning apps export GLB files. Unity can import glTF files with an appropriate package, but if you plan to use Mixamo for automatic rigging, you will need a format Mixamo accepts, such as FBX or OBJ.
One option is FurniMesh's GLB to FBX converter. FBX export requires a free account and accepts files up to 25 MB. Larger files need to be reduced first. In Blender, you can resize oversized textures and re-export the GLB, then check the result for visible loss of detail. You can also export FBX directly from Blender if that fits your workflow.
After conversion, inspect the mesh, UVs and materials. Format conversion can change material settings, and textures may need to be reconnected in Unity. Check that you have permission to upload the source model to any third-party service.
Generated models and scans can be much denser than a VRChat avatar needs to be. In Blender, enable the statistics overlay to see the triangle count. A Decimate modifier can reduce the count quickly, but inspect the result carefully: small details such as glasses, fingers and facial features can lose their shape. Apply the modifier only when you are happy with the tradeoff.
Triangle count is just one part of VRChat's avatar performance ranking. Materials, texture memory, bones and other features matter too. Check the SDK's performance panel for your target platform rather than assuming a particular triangle count guarantees an overall rank. Standalone headset limits and visibility settings also differ from PC.
For an unrigged humanoid, Mixamo's auto-rigger is one option. Upload a supported file, place the markers as instructed and download the rigged result as an FBX with skin. A clear T-pose or A-pose and a clean, human-shaped mesh give the rigger a better starting point, but unusual proportions and accessories can require manual work.
Open the result in Blender and test a few poses. Look for vertices that stretch unexpectedly, especially around clothing, hair and accessories. Correct the weights where necessary before exporting the FBX again.
Create a VRChat avatar project with Creator Companion and import the FBX into its Assets folder. Select the FBX and check its Model import settings. If the character is too small or too large, check the source units and adjust the import scale as needed; a scale factor of 100 is sometimes appropriate, but it is not universal. Compare the avatar against a default Unity cube, which is one metre on each side, and confirm the height you want.
On the Rig tab, set Animation Type to Humanoid and Avatar Definition to Create From This Model, then apply the settings. Open Configure and check the bone mapping. Assign any missing required bones and correct the pose if Unity reports a problem. Review the materials and reconnect textures where needed.
Add a VRC Avatar Descriptor to the avatar root and position the view point between the eyes. Choose a lip-sync mode supported by the model: jaw-bone mode needs a suitable jaw bone, while viseme-based modes need the corresponding blend shapes. A model with neither may need additional work before it can use those modes.
Open the VRChat SDK Builder, review the errors, warnings and performance breakdown, and fix anything required for your target platform. Test the avatar in the SDK before publishing. Check its height, viewpoint, materials and movement, and pay attention to stretched clothing or accessories.
Scans often include the surrounding floor, furniture or other unwanted geometry. Remove that in Blender before reducing the mesh and rigging it. A clean silhouette makes automatic rigging easier, but a scan may still need retopology, texture cleanup and manual weight painting. Its scale can differ from another model's, so measure and verify it independently.
The exact settings depend on the source file. Check each stage before moving on: a clean mesh, sensible texture sizes, a working rig and the right scale are more useful than copying one set of numbers for every avatar.
Header photo: Visitors engage with virtual reality equipment at a technology expo by Shixart1985, CC BY 2.0, via Wikimedia Commons. Cropped.
