| OCR Text |
Show 46 1 by fixing either formed curves (for This patches). square the u or parameter v yields Y a at function 0 or of the form To intersect of any Y ( 0, v) Y (1, v) the = Yu 0 (v) = Yu 1 (v) boundary edges with (perhaps rational cubic) this etc. the function must plane scan be solved for v in Yu The other edges, of set defined are zero. This by the two edges 0 (v) by the in each space which Yv(u,v) X can be and Z addition down their regions Yscan - substituted of to space the the by (and screen, of spans the edge normal being defined space it patch. = the the X in the and Z current position in is also necessary is, which space) which curve This XZ is not 0 = 0 thus That of into the Yu(u,v) point a on following connectivity. connected the parameter Xv(u,v) - type of edge defines parameter moves the silhouette along, equations Thus, in 0 component of Z Y(u,v) In = track to necessary generates points Xu(u,v) yield the -Yscan functions scan the as to as points scan plane keep track of pairs easy to plane. these of represent so parameter of edges are continuous for polygons |
