Physically Meaningful Rendering using Tristimulus Colours

dc.contributor.authorMeng, Johannesen_US
dc.contributor.authorSimon, Florianen_US
dc.contributor.authorHanika, Johannesen_US
dc.contributor.authorDachsbacher, Carstenen_US
dc.contributor.editorJaakko Lehtinen and Derek Nowrouzezahraien_US
dc.date.accessioned2015-06-23T04:47:43Z
dc.date.available2015-06-23T04:47:43Z
dc.date.issued2015en_US
dc.description.abstractIn photorealistic image synthesis the radiative transfer equation is often not solved by simulating every wavelength of light, but instead by computing tristimulus transport, for instance using sRGB primaries as a basis. This choice is convenient, because input texture data is usually stored in RGB colour spaces. However, there are problems with this approach which are often overlooked or ignored. By comparing to spectral reference renderings, we show how rendering in tristimulus colour spaces introduces colour shifts in indirect light, violation of energy conservation, and unexpected behaviour in participating media. Furthermore, we introduce a fast method to compute spectra from almost any given XYZ input colour. It creates spectra that match the input colour precisely. Additionally, like in natural reflectance spectra, their energy is smoothly distributed over wide wavelength bands. This method is both useful to upsample RGB input data when spectral transport is used and as an intermediate step for corrected tristimulus-based transport. Finally, we show how energy conservation can be enforced in RGB by mapping colours to valid reflectances.en_US
dc.description.number4en_US
dc.description.sectionheadersMaterial Appearanceen_US
dc.description.seriesinformationComputer Graphics Forumen_US
dc.description.volume34en_US
dc.identifier.doi10.1111/cgf.12676en_US
dc.identifier.pages031-040en_US
dc.identifier.urihttps://doi.org/10.1111/cgf.12676en_US
dc.publisherThe Eurographics Association and John Wiley & Sons Ltd.en_US
dc.subjectComputer Graphics [I.3.7]en_US
dc.subjectThree Dimensional Graphics and Realismen_US
dc.subjectColoren_US
dc.subjectshadingen_US
dc.subjectshadowingen_US
dc.subjectand textureen_US
dc.titlePhysically Meaningful Rendering using Tristimulus Coloursen_US
Files