Editing Cornell box (section)

== Reference Model ==
[[File:Cornell Box with 3 balls of different materials.jpg|thumb|300px|Cornell box with three spheres illustrating different interactions of light and surfaces.<ref group="𝓲">Picture taken at 'The Science Behind Pixar Exhibition at the Telus World of Science in Edmonton'</ref>]]
A physical model of the Cornell box is constructed and photographed using calibrated equipment. [[Cornell box#Photographic Images|Photographic image references]] shared via Cornell University website<ref name="CornellBoxData">[https://www.graphics.cornell.edu/online/box/data.html Cornell Box Data]</ref> were captured using a liquid-cooled Photometrics PXL1300L [[CCD camera]] with a precision of 12 bits. Seven narrow-band [[Photographic filter|filters]] are employed to obtain a coarse sampling across the [[visible spectrum]]. To enhance accuracy, [[Dark current (physics)|dark current]] is subtracted from the images, and [[flat-field correction]] is applied to compensate for [[Vignetting|cosine fall-off and lens fall-off]]. The precise settings of the scene are [[Measurement|measured]], including the [[emission spectrum]] of the [[Light#Light sources|light source]], [[Reflectance#Reflectance|reflectance spectra]] of all [[surface]]s, and the exact position and dimensions of objects, walls, light sources, and the camera.

A matching virtual [[Glossary of computer graphics#3d scene|3D scene]] is created, and a [[digital image]] is generated during the rendering process for comparison with the [[Photo-referencing|reference photograph]]. The comparison helps evaluate the accuracy of rendering algorithms, particularly in handling [[global illumination]], [[Radiosity (computer graphics)|radiosity]], and [[light transport]]. The Cornell box is designed to demonstrate ''[[diffuse reflection|diffuse interreflection]]''. Light reflecting off the red and green walls subtly tints the adjacent white walls, demonstrating complex global illumination effects.