cube.obj

# cube.obj
# Import into Blender with Y-forward, Z-up
#
# Vertices:                        Faces:
#      f-------g                          +-------+ 
#     /.      /|                         /.  5   /|  3 back
#    / .     / |                        / .     / |
#   e-------h  |                   2   +-------+ 1|
#   |  b . .|. c      z          right |  . . .|. +
#   | .     | /       | /y             | . 4   | /
#   |.      |/        |/               |.      |/
#   a-------d         +---- x          +-------+
#                                           6
#                                        bottom

g cube

# Vertices
v 0.0 0.0 0.0  # 1 a
v 0.0 1.0 0.0  # 2 b
v 1.0 1.0 0.0  # 3 c
v 1.0 0.0 0.0  # 4 d
v 0.0 0.0 1.0  # 5 e
v 0.0 1.0 1.0  # 6 f
v 1.0 1.0 1.0  # 7 g
v 1.0 0.0 1.0  # 8 h

# Normal vectors
# One for each face. Shared by all vertices in that face.
vn  1.0  0.0  0.0  # 1 cghd
vn -1.0  0.0  0.0  # 2 aefb
vn  0.0  1.0  0.0  # 3 gcbf
vn  0.0 -1.0  0.0  # 4 dhea
vn  0.0  0.0  1.0  # 5 hgfe
vn  0.0  0.0 -1.0  # 6 cdab

# Faces v/vt/vn
#   3-------2
#   | -     |
#   |   #   |  Each face = 2 triangles (ccw)
#   |     - |            = 1-2-3 + 1-3-4
#   4-------1

# Face 1: cghd = cgh + chd
f 3//1 7//1 8//1
f 3//1 8//1 4//1

# Face 2: aefb = aef + afb
f 1//2 5//2 6//2
f 1//2 6//2 2//2

# Face 3: gcbf = gcb + gbf
f 7//3 3//3 2//3
f 7//3 2//3 6//3

# Face 4: dhea = dhe + dea
f 4//4 8//4 5//4
f 4//4 5//4 1//4

# Face 5: hgfe = hgf + hfe
f 8//5 7//5 6//5
f 8//5 6//5 5//5

# Face 6: cdab = cda + cab
f 3//6 4//6 1//6
f 3//6 1//6 2//6