# Two triangles...
 
mtllib TwoTrianglesWithNegativeIndices.mtl
 
# FIRST TRIANGLE / GROUP:   (will be red and shiny)
g triangle1
usemtl material_for_first_triangle
v 0 0 4
v 8 0 4
v 8 2 0
f -3 -2 -1
 
# SECOND TRIANGLE / GROUP:   (will be white and transparent) 
g triangle2
usemtl material_for_second_triangle
v 0 0 4
v 4 0 4
v 4 2 4
f -3 -2 -1
