November 2017
Materialappearancemodelling
I Picka materialandcharacterizeits intrinsicvisualproperties(usephotos).
I Explore the parametersof PxrSurface(or PxrLayerSurface)and ndparameter
settingsthatreproducethe discoveredvisualpropertiesof the material.
I Providea physicalexplanationof the linkbetweenshaderparametersandvisual
properties(physicalpropertiesare recommendedoverartisticproperties).
I Constructan appearancemodel thatde nesreasonablevariationof the
parameterswithout violatingthe visualpropertiesof the material.
More lightsources
I Arealightsampling (AreaLight.cpp).
I Texturedprojector light(reversedpinholecamera).
I Spotlights(anglecut-o ).
I Directilluminationin general.
I Photonemission(samplingdirectionandposition).
I Softshadows (samplingan area light).
Renderingmirages
I Simulationof lightrays in heterogeneousmedia.
I Userefractiveplanesto haveair layers withvaryingindicesof refraction.
I Totalinternalre ectionleads to mirages.
I Try to set up scenesthatresultin di erenttypes of mirage(inferior, superior,
stooping,towering).
I Usea verticaltexturedplaneas background(for example)to show the e ect.
Extra:
I Applyjittersampling to ray exitdirection(increasingwithnumber of layers
passed),to achieverealism.
OptiX:GPUacceleratedray tracing
I Re-implementthe renderinge ectsof the coursein closesthit \shaders".
I Switchto progressiverenderingand perhaps adda samplingtechnique.
I Code samplesandquickstart guide are available.
I Thereis an OptiXversionof the renderframework.
I A projectinitiator worksheet is available.
Radiosity usingOpenGLrasterization
I Scenediscretization(meshing).
I Progressiveshootingalgorithm ndingthe maximumenergypatchin everystep.
I Nodal averagingfor linear interpolationacrosspatches (Gouraudshading).
I Hemicube renderingsfor computingvisibility (form. factors).
I A projectinitiator worksheet is available.
Completethe photonmappingalgorithm
I Directvisualisationof the photonmapis proneto low frequencynoise.
I Replacethe photonmaplook-upat the rstintersectionpoint by sampling
incidentillumination( nalgathering).
I Whenusingthe photonmapin thisway, certainlightpathswillbe missing.
I Adddirectlighting andcausticsseparately(seenotes).
I To havea proper testscene, usetheCornellbox witha glassballanda mirror ball.
E cientglossyre ectionswithRenderMan
I Buildingon the worksheetthatimplementsa customRenderManshader.
I Thesamplingschemeof the customshaderis ine cientfor glossymaterials.
I Improvethe customshaderwithimportancesamplingof the BRDFthatit uses
for generatingandevaluatingrays.
I A texton importancesamplingof MERLBRDFsis available.
I Code for generatingdistributionfunctionsfromtabulated datais available.
Ambientocclusionandenvironmentmaps
[ambientocclusion]
I Shoot shadow rays by samplinga cosine-weightedhemisphere.
I Usea uniform. whitebackgroundto get ambientocclusion.
[environmentmapping]
I Acquireenvironmentmapby photographinga chromesphere(for example).
I Loada High DynamicRange(HDR)backgroundtexture(HDRTexture.cpp).
[combination]
I Usean environmentmapto get ambientlightfromthe environment
(SphereTexture.cpp).
Progressivepathtracingof globalillumination
I Useprogressiveupdatesof camerapixels(framework patch:progressive.zip).
I Tracea ray for indirectilluminationandadddirectillumination(MCGlossy.cpp).
I Samplea cosine-weightedhemisphereto get the ray directionfor indirectlight.
I Switcho lightsourceswhentracingindirectlightfromnon-specular surfaces.
I Test the pathtracerin a di use scene,in a di usescenewithspecular objects,
andperhapsalsofor glossy/Phongobjects.
Extra:
I Importancesamplethe specular highlightof the Phongmodel.