AngelCG42山东university软件学院图形学教材.ppt

Angel: Interactive Computer Graphics 4E ? Addison-Wesley 2005 Parallel Rendering Ed Angel Professor of Computer Science, Electrical and Computer Engineering, and Media Arts Director, Arts Technology Center University of New Mexico Introduction In many situations, a standard rendering pipeline might not be sufficient Need higher resolution display More primitives than one pipeline can handle Want to use commodity components to build a system that can render in parallel Use standard network to connect Power Walls Where do we display large data sets? CRTs have low resolution (1 Mpixel) LCD panels improving but still expensive Need resolution comparable to data set to see detail CT/MRI/MEG Ocean data Solution? Multiple projectors Commodity High-end See IEECE CG A (July) Tiled Display CS Power Wall 6 dual processor Intellestations G Force 3 Graphics cards 6 commodity projectors (1024 x 768) Gigabit ethernet Back projected screen Shared facility with scalable system group Investigate OS and network issues CS Power Wall CS Power Wall Power Wall Inexpensive solution but there are some problems Color matching Vignetting Alignment Overlap areas Synching Dark field Graphics Architectures Pipeline Architecture SGI Geometry Engine Geometry passes through pipeline Hardware for clipping transformations texture mapping Building Blocks Graphics processors consist of geometric blocks and rasterizers Geometric units: transformations, clipping, lighting Rasterization: scan conversion, shading Parallelize by using mutiple blocks Where to do depth check? Sorting Paradigm We can categorize different ways of interconnecting blocks using a sorting paradigm: each projector is responsible for one area of the screen. Hence, we must sort the primitives and assign them to the proper projector Algorithms can be categorized by where this sorting occurs Three Rendering Methods Sort First Each rasterization unit assigned to an area of the screen Each geometric unit coupled to its own rasterize