Many garments that have ‘topstitches‘ (such as denim jeans and shoes) will often end up having a massive amount of separate meshes and very very high polygon counts when you export them.

The solution is to change the topstitches from 3D models to textures. (That is, they simply become part of the texture images that you export from Marvelous Designer – rather than being actual 3D meshes with polygons.)

To do that, you need to change all “topstitch” items in your scene from OBJ format to TEXTURE.

To do that:

• In the panel that has your list of fabrics, click the dropdown and change to TOPSTITCH
  
  
• Click “delete unused“
• Go through each item in the list, and change the TYPE dropdown to TEXTURE (you do NOT want it on “obj”)

Now you can export as normal:
– Go FILE > EXPORT > FBX

Then the result, in your DCC of choice, will have the topstitches baked into the textures: