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Item Estimating Mobile Memory Requirements and Rendering Time for Remote Execution of the Graphics Pipeline(The Eurographics Association, 2005) Banerjee, Kutty; Wu, Fan; Agu, Emmanuel; John Dingliana and Fabio GanovelliMobile devices have limited processing power, memory and battery power. Remote execution, wherein part or entire graphics pipeline is offloaded to a powerful surrogate server, is an attractive solution for low end mobile devices such as PDAs and cell phones that lack floating point units or GPUs. We have found that remote execution of floating-point-intensive pipeline stages such as transform and geometry operations can produce speedups of up to 10 times for a low-end mobile device. We introduce generalized pipeline-splitting, a paradigm whereby 15 sub-stages of the graphics pipeline are instrumented with networking code such that they can run either on a mobile client or a surrogate server. To validate our concepts, we create Remote Mesa (RMesa). As a foundation for deciding which stages of the pipeline would benefit from remote execution, this paper presents analytical models for the overall rendering time, memory requirements and roundtrip network delay incurred by RMesa.Item Spherical Harmonic Lighting of Wavelength-Dependent Phenomena(The Eurographics Association, 2005) Lindsay, Clifford; Agu, Emmanuel; John Dingliana and Fabio GanovelliRendering of objects that exhibit iridescence has previously been limited to simple lighting conditions generated from a few point or directional lights. We extend this idea by modeling light interference as a Bidirectional Re- flectance Distribution Function (BRDF) and precomputing the physically based surface response to hemisphere lighting in terms of a low order spherical harmonic basis. Parameterizing by view direction, we can store the light interference effect in a 2D texture map, where each entry contains a vector of spherical harmonic basis function coefficients. Our technique achieves a full spectral representation of interference color by maintaining the spherical harmonic basis in terms of Spectral Power Distribution (SPD) instead of a color-based format such as RGB. In addition, we demonstrate that our approach is amenable to current graphics hardware and can render at real-time frame rates.Item Pareto-Based Perceptual Metric for Imperceptible Simplification on Mobile Displays(The Eurographics Association, 2007) Wu, Fan; Agu, Emmanuel; Lindsay, Clifford; Paolo Cignoni and Jiri SochorGraphics on mobile devices has become popular because untethered computing is convenient and increases pro- ductivity. Mobile displays come in different resolutions that affect the scene Level-of-Detail (LoD) that users can perceive: smaller displays show less detail, making lower resolution meshes and textures acceptable. Mobile de- vices frequently have limited battery energy, low memory and disk space. To minimize wasting system resources, we try to render mobile graphics scenes at the lowest LoD at which users do not perceive distortion due to sim- plification. We call this LoD the Point of Imperceptibility (PoI). The PoI LoD depends on several factors including screen size, scene geometry and lighting levels. We propose a perceptual metric that identifies the PoI LoD of a target mobile display and accounts for object geometry, lighting and shading. Our perceptual metric generates a screen-dependent pareto distribution with a knee point that corresponds to the PoI. We employ wavelets for simplification, which gives direct access to the mesh undulation frequency that we then use to parametrize the perceptual CSF curve.