Prise3D/p3d_pbrt-v4-scenes: PBRT v4 scenes for SIN3D

Matt Pharr 02708382b8 Update scenes to use "iso" rather than "scale" for Film		4 lat temu
..
geometry	449d32c872 Add sssdragon scene	4 lat temu
textures	449d32c872 Add sssdragon scene	4 lat temu
dragon_10.pbrt	02708382b8 Update scenes to use "iso" rather than "scale" for Film	4 lat temu
dragon_250.pbrt	02708382b8 Update scenes to use "iso" rather than "scale" for Film	4 lat temu
dragon_50.pbrt	02708382b8 Update scenes to use "iso" rather than "scale" for Film	4 lat temu