A set of example materials in OSPRay
IMPORTANT You will need to manually edit knobs.ospg and replace the paths for the objs with the correct paths for your system.
run as:
./ospExampleViewer knobs.ospsg -vp 3.671165 1.327651 -1.469197 -vu 0.000000 1.000000 0.000000 -vi 2.475927 -0.222146 1.035521 -sun:intensity=3 --no-plane
currently resolving a few issues with materials. Material instancing not yet supported, so every material has its own obj model.