GLB and GLTF don't currently support bump maps for texture but they do support Normal maps. Here's the recipe I used to get it into my GLB for After Effects.
UV Setup:
Select object and go to UV Layout workspace
TAB to Edit Mode, select all points (enable "see behind" checkbox)
UV > Smart UV Project
Optional: Turn on UV Sync button and UV Stretch indicator for better control
Keep Image Viewer window open to monitor progress
Prepare the Bake Target:
Switch to Shader Layout
Add new Image Texture node to your material
Create new blank image (PNG, 1024x1024)
Save the image
Bake Settings:
Set Renderer to Cycles (Max samples ~16)
Bake panel: Type > Normal, Space > Tangent
Select both object and Image Texture node
Hit Bake button
Connect the Normal Map:
Replace procedural bump chain with baked normal map
Connect: Image Texture > UV Texture node (Tangent space) > Normal input of BSDF
Skip Linear color space conversion (caused me issues, anyway)
References:https://www.youtube.com/watch?v=7hha_KejNJ0
Blender Guru's Anvil tutorial
