when I was in blender the model looked okay but then when importing it did these
how do I fix that?
Show what the models look like in Blender.
It looks like it could be an issue with a flipped normal or something is wrong with your mesh topology.
This may help you for flipped normals.
If not try solidifying the mesh (using the solidify mod (Don’t use too large of a thickness and make sure the value as to which side it extends is 0 (for even thickness))) and seeing what the outcome is of that.
Flipped normals (press alt+n on the faces and turn on face orientation)
I’ve tried importing just a block from blender into studio and it did this. What I did was just go into properties in studio for the mesh part, and checked “Double Sided”, then it showed it right. If you need info on the “double sided” property, get information Here (roblox devforum)
The normals are inverted, you have to recalculate them.
Ctrl + N for Blender 2.79
Shift + N for Blender 2.9
If these don’t work go into your keymap (edit > preferences > keymap > search “recalculate” > and look for the mesh grouping)
Forgot to say you have to select every face, vert or edge in edit mode (easy way of doing that is just by going into edit mode and pressing A) and then do the shortcut, if you want to check that it is working enable Backface Culling.
Just realised that someone else had also said the same thing, disregard.