Revert "makersthree.js: added support for mesh_use_embedded_materials=false"

This reverts commit 19715a268d0dd041c21031b3543536035d5d5557.
Revert "Revert "makersthree.js: added support for mesh_use_embedded_materials=false""

This reverts commit 2349c817034733618ac6385d1327ed7f98110cee.