A collection of 61 real-world is surfaces used in the measurements.
The samples were chosen to span a wide
range of geometric and photometric properties.
The categories include
specular surfaces (aluminum foil, artificial grass),
diffuse surfaces (plaster, concrete),
isotropic surfaces (cork, leather, styrofoam),
anisotropic surfaces (straw, corduroy, corn husk),
surfaces with large height variations (crumpled paper, terrycloth, pebbles),
surfaces with small height variations (sandpaper, quarry tile, brick),
pastel surfaces (paper, cotton),
colored surfaces (velvet, rug),
natural surfaces (moss, lettuce, fur)
and man-made surfaces (sponge, terrycloth, velvet).
Different samples of the same type of surfaces are
denoted by letters, e.g. Brick_a and Brick_b.
Samples 29, 30, 31 and 32 are close-up views of samples 2, 11, 12 and