I have downloaded few 3D models from sketchfab website. Imported them to blender and exported using gltf exporter to .gltf file and used the same file in three js to display the 3D image on browser...(I didn't apply textures in blender as I want to apply the texture files directly in threejs). I could do everything successfully but unable to understand how to map the texture files in three js... i.e. the downloaded zip from sketchfab contains 3 texture files and I need to apply them to the 3D object... How to decide what maps to use i.e. diffusemap, specular map etc....to apply these textures. Also, I want to decide the texture map programmatically based on texture image... Is it possible? I need to decide it programmatically only because the end user who uses my application will just give the 3d model i.e. (.obj, .3ds etc...) file as input along with the texture files and expect to see the full 3D object on browser with perfectly applied textures. Can anyone please help me on this?