This is what most beginners struggle with, thanks to glTF we have a much better format which works for most features. Still a lot tools don’t support it or like in my case, i would have to upgrade with about $1000 to the latest C4D where this feature got added.
I would like to know how good your workflow with your modelling tool and the choice of format works for you. A lot formats crop off features such as animations, morph buffers and material features. Currently only glTF exports all PBR maps.
The tool, the format, it’s version, the exporter and the loader can all shrink the amount of information handled, especially with feature rich formats like FBX or COLLADA there are many versions what can make them incompatible with the loader for THREE.
I personally experienced with FBX from Cinema 4D and Blender that there is only a minimal amount of information exported, materials especially don’t store back/frontface culling, transparency, opacity and many other features that have to be fixed in another step. FBX works best since it supports animations, i use a converter which applies all further details and stores it in a binary format, for any converter instructions i use the object and material names to store information. But another flaw of the exporter or C4D is, if the UV map is split up, it will turn the entire mesh into a non-indexed geometry, i have to fix in the convertion step as well.