ࡱ> /1.` Rbjbj 2/VVVV b Dzzzzzzzz.000000$ hs BT-zzzzzTzz222zzz.2z.222zn ı?V"2.02  220 bzz2zzzzzTT( zzzzzzz Real-Time Rendering of Plant Leaves Realistic rendering of leaves is an open problem and has a long history in computer graphics, which can be widely used in CG movies and graphics games. This paper tries to solve this difficult problem. Plant leaves are translucent with complicated surface tissues, and the light interactions of leaves are complex and subtle. All these make it extremely difficult to render leaves realistically especially in case of real-time. Leaf rendering requires a sophisticated appearance model and accurate lighting computation, thus traditional real-time leaf rendering techniques always handled leaves with textured polygons, which are not realistic. Our paper presents a new framework for the real-time rendering of plant leaves with global illumination effects. It introduces a new parametric model that describes leaves in terms of spatially-variant BRDFs and BTDFs. These BRDFs and BTDFs, incorporating analysis of subsurface scattering inside leaf tissues and rough surface scattering on leaf surfaces, can be measured from real leaves. More importantly, this description is compact and can be loaded into graphics hardware for fast run-time shading calculations, which are essential for achieving high frame rates. For lighting computation, our system extends the Precomputed Radiance Transfer (PRT) approach to all-frequency lighting for leaves, which combines illumination effects due to low frequency environment light and high-frequency sunlight. This technique can also be used in rendering of other translucent object and has widely applications. [ev iirSP[2ngb/g ؚ^w[av iirSP[2ngwQ g`ENvSS,_N/fVb_f[vN*N` *gQv [SN^l0W^(uNCG5uq_T8nb-N0,ge1\/f[ُvN*Ncb0 iirvSP[/fJSfirSO Nhb~~~g^8^ YBg fNYtv/fSP[v YBgTOeavIQgqHe^0@b gُNV }OSP[vw[a2ng^8^V $\vQ/f(W[eYtv:WT0SP[v2ng YBgvSGr!jWT|nxvIQgq{0(W O~v[eb/g-N ~8^(u{USv~tegfNSGrhbTIQgq!jb N 1YSw[a0,gecQvev2ng|~SN(ueg㉳QhQ@\IQgqsX Nvw[aSP[v[e2ng0ezHQN~NN*NevSpeS!jW0ُ*N!jWS+TvzzSSvSTS\T\QpeSN gHeYtSP[hbT!khbv YBgIQgqSS ͑v/fُNIQgqSSSNNw[SP[-NbDdSf͑v/f ُy'}Qvhe_TIQgqЏ{SN(us gvVb_lxNRegۏL N [s[hQ[ev2ng[NhQ@\IQgqvYt ,geibU\N O~v {vIQgq O (PRT)$hjϻϯϯϭϦ hzhUhzhzCJKHo(&hzhz5CJKHOJQJ^Jo(hzhzCJKH$hzhzCJKHOJQJ^JaJ#hzhz5CJKHOJQJ^J$hj$1$WD`a$gdz$1$H$WDd`a$gdz $1$a$gdzb/g OcNhQ&^vIQgqHeg01\/feOcNؚsvIQgqHegOY3IQv4q_ SOYuNNOsIQgqHegOYsXIQ0ُyb/g_NSN(ueg2ngvQNvJSfirSO wQ g^lv^(u0 0182P. A!"#$% V@V Normal $1$a$$CJKHPJ_HaJmH nHsH tHDA@D Default Paragraph FontRi@R  Table Normal4 l4a (k@(No List/$45A.10000000000y00$45A.10000000000 00.   rw|5@ATUnp-15@A-111|+cJuMlOJcJuMlOJ-,k1voGu6i 9()Pj,+45- =X&CHrPtV`f6ij" n5t:tCG`xTx6[+k@mJ~Dl\h-dz C?fo`@..5 ..(/P@PPUnknownGz Times New Roman5Symbol3& z ArialQ& {aMicrosoft Sans Serif;[SOSimSun qhz&z&88$-!),.:;?]}    & 6"0000 0 0 00000 =@\]^([{  0 0 00000;[r++2AHX(?z2lfwanglfwangOh+'0X    ,8@HPlfwang Normal.dotlfwang2Microsoft Office Word@@>@>8՜.+,0 hp  Microsoft Corporation+  Title  !"#$%'()*+,-0Root Entry Fa?2Data 1TableWordDocument2SummaryInformation(DocumentSummaryInformation8&CompObjq  FMicrosoft Office Word Document MSWordDocWord.Document.89q