# Simple unit cube — consistent CCW winding (viewed from outside)
v -0.5 -0.5 -0.5
v  0.5 -0.5 -0.5
v  0.5  0.5 -0.5
v -0.5  0.5 -0.5
v -0.5 -0.5  0.5
v  0.5 -0.5  0.5
v  0.5  0.5  0.5
v -0.5  0.5  0.5

# Back face (normal -Z, CCW from outside = looking from -Z)
f 1 4 3
f 1 3 2

# Front face (normal +Z, CCW from outside = looking from +Z)
f 5 6 7
f 5 7 8

# Left face (normal -X, CCW from outside = looking from -X)
f 1 5 8
f 1 8 4

# Right face (normal +X, CCW from outside = looking from +X)
f 2 3 7
f 2 7 6

# Bottom face (normal -Y, CCW from outside = looking from -Y)
f 1 2 6
f 1 6 5

# Top face (normal +Y, CCW from outside = looking from +Y)
f 4 8 7
f 4 7 3