GLB Tutorials

These tutorials can help you meet our asset requirements when exporting your 3D assets as GLB files.

General Considerations

• We support GLB files (GLB is the binary version of the glTF 2.0 file format).
• Your GLB must be under 3MB in total. The smaller the better.
• Strip out unused data whenever possible. Unused vertex colors, UV's, etc. all add to the file size.
• Use PNG or JPEG files for textures.
• Use JPEG files unless you need transparency. This will make your files much smaller.
• Textures must be power-of-2 in each dimension (512x1024 for example).
• Textures can be up to 4k, but try to keep them under 2k.
• Once you have a GLB file, you can just drag it into a new post, pick a background color and share it.
• The PBR shader can use these textures:

  • Base Color (rgba, with alpha optionally driving transparency)
  • Normal
  • Emissive
  • ORM (Packed into channels in a single texture: Red has the Occlusion texture, Green has the Roughness texture and Blue has the Metalness texture.)
• Additionally, the PBR shader will use vertex color, if present.

Converting FBX to glTF

You can download our FBX to glTF converter program from GitHub. Here's a direct link to the compiled versions for Mac, Windows, and Linux:

https://github.com/facebookincubator/FBX2glTF/releases

On a Windows PC

Open up a terminal window and from the folder with the FBX2glTF program run:

FBX2glTF-windows-x64.exe /path/to/fileFBX -b

This will make a binary glTF file (a GLB file) that includes your textures and save it into the same directory as the FBX2glTF program. These steps are pictured below.

Find the FBX file that you'd like to convert:

Open up a terminal window and run the conversion program with the -b option to make a GLB.

It will generate a GLB from your FBX file and put it in the same folder as the FBX2glTF program:

On a Mac

First, download FBX2glTF-darwin-x64, then open up a Terminal window and go to the directory with the program and move the program into a command directory:

mv FBX2glTF-darwin-x64 /user/local/bin/FBX2glTF

Next, set permissions on it so you can run it:

chmod 755 /user/local/bin/FBX2glTF

In the directory with the FBX file you'd like to convert, run this command:

FBX2glTF your-filenameFBX -b

This will create your new GLB file in the same directory.

Converting glTFs to GLBs

3D Posts require GLB files. You can convert a glTF to a GLB using our GLB Packer:

https://glb-packer.glitch.me

Just drag your glTF, its .bin and any textures it uses onto the website. The website will automatically generate and download a packed GLB file suitable for 3D Posts.

If your asset uses PNG files, be sure to check the "Convert PNG to JPEG" first. This will make your GLB significantly smaller and load faster for your viewers.

Shaders & Materials

We support two shading models: PBR and Unlit.

PBR

Unlit

This unlit example is using vertex color.

1. You can convert a glTF file to use “Unlit” by using this website.
2. Check the “Convert to KHR_materials_unlit” box.
3. Drag a folder with your glTF into the website. It will immediately download a packed GLB with the materials set to “Unlit”.

Blender and 3ds Max

Refer to these Khronos Group pipeline instructions and make sure that you choose GLB as your export format.

Maya

For a full PBR workflow in Maya, use the Stingray material.

Export an FBX file and then convert it to glTF. Your PBR settings will be preserved. The FBX2glTF converstion program will automatically swizzle your packed textures properly.

Modo

As of Modo 11.2v3, you can author and export GLB files directly using the glTF materials and export options. This is the most direct way to author GLB files, and you can author using full PBR along with vertex color.

Here's a YouTube video showing this process, and here's a sample Modo project file that has been configured with the necessary export settings.

To export from Modo directly, use the glTF material, set your viewport to Advanced, then assign textures and tune your materials.

Occlusion, Roughness and Metalness are packed into the ORM texture, so you have to swizzle them to see them properly.

Transparency is driven by the alpha channel of your Base Texture. In Modo 11.2v3, make a duplicate of your Base Texture, set its effect to transparent amount, and swizzle the alpha channel into it.

Use “Export As” to write out a GLB file that includes all of your textures (glTF leaves the textures loose).

Please note that 3D Posts display in gamma 2.2. Modo's “Vertex Map” and “Texture” display settings are in linear gamma, so vertex colors that look good in Modo will appear washed out in Facebook Posts.

Paint 3D

Microsoft's Paint 3D now allows you to export GLBs:

Substance Painter

You can directly export a GLB out of Substance Painter and then drag it into a new post. Keep your textures as small as you can, ideally under 2k, but no more than 4k.

To export from Substance Painter, go to Export Textures...

... and choose the glTF PBR Metal Roughness option. It will export the textures, a GLB and a glTF file into your export folder.

GLBs for 3D Posts must be under 3MB. The easiest way to do this is to use JPEG textures instead of PNGs. Unfortunately, Substance Painter doesn't support this, so use our GLB Packer to convert your glTF to a GLB that uses JPEGs instead of PNGs. The packer will automatically convert your textures to JPEGs and create a new GLB for you.

Sketchfab

You can upload most 3D formats to Sketchfab, tweak stuff, then export a glTF. Once you have a glTF, you can easily convert it to a GLB using using our GLB Packer.

Verge3D

Verge3D has posted their own tutorial for creating 3D Posts in Verge3D.