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Item Planned Sampling of Spatially Varying BRDFs(Blackwell Publishers, Inc and the Eurographics Association, 2003) Lensch, Hendrik P.A.; Lang, Jochen; Sa, Asla M.; Seidel, Hans-PeterMeasuring reflection properties of a 3D object involves capturing images for numerous viewing and lightingdirections. We present a method to select advantageous measurement directions based on analyzing the estimationof the bi-directional reflectance distribution function (BRDF). The selected directions minimize the uncertaintyin the estimated parameters of the BRDF. As a result, few measurements suffice to produce models that describethe reflectance behavior well. Moreover, the uncertainty measure can be computed fast on modern graphics cardsby exploiting their capability to render into a floating-point frame buffer. This forms the basis of an acquisitionplanner capable of guiding experts and non-experts alike through the BRDF acquisition process. We demonstratethat spatially varying reflection properties can be captured more efficiently for real-world applications using ouracquisition planner.Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-DimensionalGraphics and Realism Virtual Reality I.4.1 [Computer Vision]: Digitization and Image Capture, ReflectanceItem Shadow Volumes on Programmable Graphics Hardware(Blackwell Publishers, Inc and the Eurographics Association, 2003) Brabec, Stefan; Seidel, Hans-PeterOne of the best choices for fast, high quality shadows is the shadow volume algorithm. However, for real timeapplications the extraction of silhouette edges can significantly burden the CPU, especially with highly tessellatedinput geometry or when complex geometry shaders are applied.In this paper we show how this last, expensive part of the shadow volume method can be implemented on programmablegraphics hardware. This way, the originally hybrid shadow volumes algorithm can now be reformulatedas a purely hardware-accelerated approach.The benefits of this implementation is not only the increase in speed. Firstly, all computations now run on thesame hardware resulting in consistent precision within all steps of the algorithm. Secondly, programmable vertextransformations are no longer problematic when applied to shadow casting objects.Categories and Subject Descriptors (according to ACM CCS): I.3.1 [Computer Graphics]: Hardware Architecture;I.3.3 [Computer Graphics]: Picture/Image Generation; I.3.7 [Computer Graphics]: Three-Dimensional Graphicsand Realism