{"responseHeader":{"status":0,"QTime":4,"params":{"q":"{!q.op=AND}id:\"101812\"","hl":"true","hl.simple.post":"","hl.fragsize":"5000","fq":"!embargo_tdt:[NOW TO *]","hl.fl":"ocr_t","hl.method":"unified","wt":"json","hl.simple.pre":""}},"response":{"numFound":1,"start":0,"docs":[{"file_name_t":"Malley-A_Shading_Method.pdf","thumb_s":"/23/b2/23b2d030270b671aa4e70af929a21cedf481fe23.jpg","oldid_t":"compsci 9925","setname_s":"ir_computersa","restricted_i":0,"format_t":"application/pdf","modified_tdt":"2016-05-25T00:00:00Z","file_s":"/bb/3c/bb3c68ae820df9eb29d788b62a707f0204cfea39.pdf","title_t":"Page 28","ocr_t":"16 form factor calculations comprised about 90 % of the time to calculate an image when starting from the description of a scene. This is somewhat misleading, because a scene can be rendered from multiple views, lightings, and color schemes (reflectivities) based on a single form factor calculation. (The form factors remain valid as long as the geometry does not change.) To calculate the form factors, between 7,500 and 30,000 squares on the cube surface were used. The form factor values are used in the matrix solution to produce the radiosity values. The scene can then be scan converted. At each visible point, the radiosity is interpolated or extrapolated from the nearest solution points providing a smoothed result for use in intensity calculations. 2.9.2 Solution for Incident Radiosity Nishita and Nakamae described a radiosity solution for incident (as opposed to emergent) radiosity [26]. This solution results in a similar matrix formulation to solve for the unknown radiosities, but differs from that of Cohen and Greenberg [9] in some basic ways. The radiosities are calculated at polygon vertices instead of at a point inside each polygon. Radiosity values at interior points are always the result of bilinear interpolation, and extrapolation is never necessary. Nishita and Nakamae's approach is also different because it uses point-to-point visibility checks rather than projecting an area onto a sample space for hidden surface processing. Table 2.5 introduces additional terms to avoid ambiguity. Figure 2.6 is a schematic representation of this approach. The corresponding ·matrix equation is (2.12) where (2.13)","id":101812,"created_tdt":"2016-05-25T00:00:00Z","parent_i":101866,"_version_":1679953745192943616}]},"highlighting":{"101812":{"ocr_t":[]}}}