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/* Copyright (c) 1992 Regents of the University of California */ |
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|
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#ifndef lint |
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< |
static char SCCSid[] = "$SunId$ LBL"; |
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> |
static const char RCSid[] = "$Id$"; |
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#endif |
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|
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/* |
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* Shading functions for anisotropic materials. |
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*/ |
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|
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/* ==================================================================== |
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* The Radiance Software License, Version 1.0 |
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* |
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* Copyright (c) 1990 - 2002 The Regents of the University of California, |
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* through Lawrence Berkeley National Laboratory. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* |
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* 3. The end-user documentation included with the redistribution, |
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* if any, must include the following acknowledgment: |
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* "This product includes Radiance software |
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* (http://radsite.lbl.gov/) |
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* developed by the Lawrence Berkeley National Laboratory |
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* (http://www.lbl.gov/)." |
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* Alternately, this acknowledgment may appear in the software itself, |
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* if and wherever such third-party acknowledgments normally appear. |
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* |
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* 4. The names "Radiance," "Lawrence Berkeley National Laboratory" |
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* and "The Regents of the University of California" must |
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* not be used to endorse or promote products derived from this |
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* software without prior written permission. For written |
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* permission, please contact [email protected]. |
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* |
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* 5. Products derived from this software may not be called "Radiance", |
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* nor may "Radiance" appear in their name, without prior written |
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* permission of Lawrence Berkeley National Laboratory. |
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* |
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* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
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* DISCLAIMED. IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR |
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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* SUCH DAMAGE. |
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* ==================================================================== |
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* |
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* This software consists of voluntary contributions made by many |
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* individuals on behalf of Lawrence Berkeley National Laboratory. For more |
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* information on Lawrence Berkeley National Laboratory, please see |
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* <http://www.lbl.gov/>. |
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*/ |
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|
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#include "ray.h" |
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|
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#include "otypes.h" |
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|
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#include "random.h" |
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|
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< |
extern double specthresh; /* specular sampling threshold */ |
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< |
extern double specjitter; /* specular sampling jitter */ |
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> |
#ifndef MAXITER |
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> |
#define MAXITER 10 /* maximum # specular ray attempts */ |
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> |
#endif |
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|
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/* |
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< |
* This anisotropic reflection model uses a variant on the |
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< |
* exponential Gaussian used in normal.c. |
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* This routine implements the anisotropic Gaussian |
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* model described by Ward in Siggraph `92 article. |
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* We orient the surface towards the incoming ray, so a single |
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* surface can be used to represent an infinitely thin object. |
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* |
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* 8 red grn blu rspec u-rough v-rough trans tspec |
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*/ |
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|
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#define BSPEC(m) (6.0) /* specularity parameter b */ |
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|
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/* specularity flags */ |
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#define SP_REFL 01 /* has reflected specular component */ |
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#define SP_TRAN 02 /* has transmitted specular */ |
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FVECT vrefl; /* vector in reflected direction */ |
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FVECT prdir; /* vector in transmitted direction */ |
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FVECT u, v; /* u and v vectors orienting anisotropy */ |
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< |
double u_alpha2; /* u roughness squared */ |
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< |
double v_alpha2; /* v roughness squared */ |
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> |
double u_alpha; /* u roughness */ |
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> |
double v_alpha; /* v roughness */ |
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double rdiff, rspec; /* reflected specular, diffuse */ |
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double trans; /* transmissivity */ |
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double tdiff, tspec; /* transmitted specular, diffuse */ |
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double pdot; /* perturbed dot product */ |
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} ANISODAT; /* anisotropic material data */ |
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|
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+ |
static void getacoords(); |
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static void agaussamp(); |
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|
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+ |
|
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static void |
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diraniso(cval, np, ldir, omega) /* compute source contribution */ |
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COLOR cval; /* returned coefficient */ |
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register ANISODAT *np; /* material data */ |
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au2 = av2 = omega/(4.0*PI); |
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else |
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au2 = av2 = 0.0; |
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< |
au2 += np->u_alpha2; |
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< |
av2 += np->v_alpha2; |
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> |
au2 += np->u_alpha*np->u_alpha; |
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> |
av2 += np->v_alpha*np->v_alpha; |
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/* half vector */ |
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h[0] = ldir[0] - np->rp->rdir[0]; |
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h[1] = ldir[1] - np->rp->rdir[1]; |
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h[2] = ldir[2] - np->rp->rdir[2]; |
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– |
normalize(h); |
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/* ellipse */ |
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dtmp1 = DOT(np->u, h); |
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dtmp1 *= dtmp1 / au2; |
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dtmp2 = DOT(np->v, h); |
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dtmp2 *= dtmp2 / av2; |
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/* gaussian */ |
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< |
dtmp = (dtmp1 + dtmp2) / (1.0 + DOT(np->pnorm, h)); |
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< |
dtmp = exp(-2.0*dtmp) * 1.0/(4.0*PI) |
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> |
dtmp = DOT(np->pnorm, h); |
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> |
dtmp = (dtmp1 + dtmp2) / (dtmp*dtmp); |
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> |
dtmp = exp(-dtmp) * (0.25/PI) |
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* sqrt(ldot/(np->pdot*au2*av2)); |
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/* worth using? */ |
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if (dtmp > FTINY) { |
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*/ |
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/* roughness + source */ |
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au2 = av2 = omega / PI; |
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< |
au2 += .25 * np->u_alpha2; |
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< |
av2 += .25 * np->v_alpha2; |
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> |
au2 += np->u_alpha*np->u_alpha; |
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> |
av2 += np->v_alpha*np->v_alpha; |
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/* "half vector" */ |
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h[0] = ldir[0] - np->prdir[0]; |
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h[1] = ldir[1] - np->prdir[1]; |
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h[2] = ldir[2] - np->prdir[2]; |
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< |
dtmp = DOT(h,np->pnorm); |
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< |
dtmp = DOT(h,h) - dtmp*dtmp; |
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> |
dtmp = DOT(h,h); |
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if (dtmp > FTINY*FTINY) { |
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< |
dtmp1 = DOT(h,np->u); |
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< |
dtmp1 = dtmp1*dtmp1 / (au2*dtmp); |
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< |
dtmp2 = DOT(h,np->v); |
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< |
dtmp2 = dtmp2*dtmp2 / (av2*dtmp); |
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< |
dtmp = 2. - 2.*DOT(ldir,np->prdir); |
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< |
dtmp *= dtmp1 + dtmp2; |
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> |
dtmp1 = DOT(h,np->pnorm); |
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> |
dtmp = 1.0 - dtmp1*dtmp1/dtmp; |
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> |
if (dtmp > FTINY*FTINY) { |
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> |
dtmp1 = DOT(h,np->u); |
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> |
dtmp1 *= dtmp1 / au2; |
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> |
dtmp2 = DOT(h,np->v); |
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> |
dtmp2 *= dtmp2 / av2; |
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> |
dtmp = (dtmp1 + dtmp2) / dtmp; |
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> |
} |
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} else |
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dtmp = 0.0; |
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/* gaussian */ |
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< |
dtmp = exp(-dtmp) * 1.0/(4.0*PI) |
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> |
dtmp = exp(-dtmp) * (1.0/PI) |
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* sqrt(-ldot/(np->pdot*au2*av2)); |
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/* worth using? */ |
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if (dtmp > FTINY) { |
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} |
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|
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|
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+ |
int |
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m_aniso(m, r) /* shade ray that hit something anisotropic */ |
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register OBJREC *m; |
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register RAY *r; |
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{ |
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ANISODAT nd; |
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double dtmp; |
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COLOR ctmp; |
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register int i; |
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/* easy shadow test */ |
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if (r->crtype & SHADOW) |
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< |
return; |
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> |
return(1); |
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|
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if (m->oargs.nfargs != (m->otype == MAT_TRANS2 ? 8 : 6)) |
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objerror(m, USER, "bad number of real arguments"); |
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m->oargs.farg[2]); |
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/* get roughness */ |
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nd.specfl = 0; |
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< |
nd.u_alpha2 = m->oargs.farg[4]; |
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< |
nd.u_alpha2 *= nd.u_alpha2; |
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< |
nd.v_alpha2 = m->oargs.farg[5]; |
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< |
nd.v_alpha2 *= nd.v_alpha2; |
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< |
if (nd.u_alpha2 < FTINY*FTINY || nd.v_alpha2 <= FTINY*FTINY) |
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> |
nd.u_alpha = m->oargs.farg[4]; |
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> |
nd.v_alpha = m->oargs.farg[5]; |
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> |
if (nd.u_alpha < FTINY || nd.v_alpha <= FTINY) |
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objerror(m, USER, "roughness too small"); |
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< |
/* reorient if necessary */ |
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< |
if (r->rod < 0.0) |
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< |
flipsurface(r); |
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> |
/* check for back side */ |
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> |
if (r->rod < 0.0) { |
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> |
if (!backvis && m->otype != MAT_TRANS2) { |
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> |
raytrans(r); |
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> |
return(1); |
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> |
} |
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> |
flipsurface(r); /* reorient if backvis */ |
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> |
} |
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/* get modifiers */ |
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raytexture(r, m->omod); |
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nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */ |
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else |
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setcolor(nd.scolor, 1.0, 1.0, 1.0); |
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scalecolor(nd.scolor, nd.rspec); |
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– |
/* improved model */ |
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– |
dtmp = exp(-BSPEC(m)*nd.pdot); |
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– |
for (i = 0; i < 3; i++) |
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– |
colval(nd.scolor,i) += (1.0-colval(nd.scolor,i))*dtmp; |
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– |
nd.rspec += (1.0-nd.rspec)*dtmp; |
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/* check threshold */ |
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< |
if (specthresh > FTINY && |
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< |
(specthresh >= 1.-FTINY || |
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< |
specthresh + .05 - .1*frandom() > nd.rspec)) |
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> |
if (specthresh >= nd.rspec-FTINY) |
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nd.specfl |= SP_RBLT; |
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/* compute refl. direction */ |
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for (i = 0; i < 3; i++) |
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if (nd.tspec > FTINY) { |
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nd.specfl |= SP_TRAN; |
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/* check threshold */ |
| 303 |
< |
if (specthresh > FTINY && |
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< |
(specthresh >= 1.-FTINY || |
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< |
specthresh + .05 - .1*frandom() > nd.tspec)) |
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> |
if (specthresh >= nd.tspec-FTINY) |
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nd.specfl |= SP_TBLT; |
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if (DOT(r->pert,r->pert) <= FTINY*FTINY) { |
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VCOPY(nd.prdir, r->rdir); |
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} else { |
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for (i = 0; i < 3; i++) /* perturb */ |
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< |
nd.prdir[i] = r->rdir[i] - |
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< |
0.5*r->pert[i]; |
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> |
nd.prdir[i] = r->rdir[i] - r->pert[i]; |
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if (DOT(nd.prdir, r->ron) < -FTINY) |
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normalize(nd.prdir); /* OK */ |
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else |
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/* diffuse reflection */ |
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nd.rdiff = 1.0 - nd.trans - nd.rspec; |
| 321 |
|
|
| 322 |
< |
if (r->ro != NULL && (r->ro->otype == OBJ_FACE || |
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< |
r->ro->otype == OBJ_RING)) |
| 322 |
> |
if (r->ro != NULL && isflat(r->ro->otype)) |
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|
nd.specfl |= SP_FLAT; |
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|
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getacoords(r, &nd); /* set up coordinates */ |
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agaussamp(r, &nd); |
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|
|
| 330 |
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if (nd.rdiff > FTINY) { /* ambient from this side */ |
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< |
ambient(ctmp, r); |
| 331 |
> |
ambient(ctmp, r, nd.pnorm); |
| 332 |
|
if (nd.specfl & SP_RBLT) |
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scalecolor(ctmp, 1.0-nd.trans); |
| 334 |
|
else |
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addcolor(r->rcol, ctmp); /* add to returned color */ |
| 338 |
|
} |
| 339 |
|
if (nd.tdiff > FTINY) { /* ambient from other side */ |
| 340 |
+ |
FVECT bnorm; |
| 341 |
+ |
|
| 342 |
|
flipsurface(r); |
| 343 |
< |
ambient(ctmp, r); |
| 343 |
> |
bnorm[0] = -nd.pnorm[0]; |
| 344 |
> |
bnorm[1] = -nd.pnorm[1]; |
| 345 |
> |
bnorm[2] = -nd.pnorm[2]; |
| 346 |
> |
ambient(ctmp, r, bnorm); |
| 347 |
|
if (nd.specfl & SP_TBLT) |
| 348 |
|
scalecolor(ctmp, nd.trans); |
| 349 |
|
else |
| 354 |
|
} |
| 355 |
|
/* add direct component */ |
| 356 |
|
direct(r, diraniso, &nd); |
| 357 |
+ |
|
| 358 |
+ |
return(1); |
| 359 |
|
} |
| 360 |
|
|
| 361 |
|
|
| 362 |
< |
static |
| 362 |
> |
static void |
| 363 |
|
getacoords(r, np) /* set up coordinate system */ |
| 364 |
|
RAY *r; |
| 365 |
|
register ANISODAT *np; |
| 389 |
|
} |
| 390 |
|
|
| 391 |
|
|
| 392 |
< |
static |
| 392 |
> |
static void |
| 393 |
|
agaussamp(r, np) /* sample anisotropic gaussian specular */ |
| 394 |
|
RAY *r; |
| 395 |
|
register ANISODAT *np; |
| 398 |
|
FVECT h; |
| 399 |
|
double rv[2]; |
| 400 |
|
double d, sinp, cosp; |
| 401 |
+ |
int niter; |
| 402 |
|
register int i; |
| 403 |
|
/* compute reflection */ |
| 404 |
|
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL && |
| 405 |
|
rayorigin(&sr, r, SPECULAR, np->rspec) == 0) { |
| 406 |
|
dimlist[ndims++] = (int)np->mp; |
| 407 |
< |
d = urand(ilhash(dimlist,ndims)+samplendx); |
| 408 |
< |
multisamp(rv, 2, d); |
| 409 |
< |
d = 2.0*PI * rv[0]; |
| 410 |
< |
cosp = cos(d); |
| 411 |
< |
sinp = sin(d); |
| 412 |
< |
d = sqrt(np->u_alpha2*cosp*cosp + np->v_alpha2*sinp*sinp); |
| 413 |
< |
cosp /= d; |
| 414 |
< |
sinp /= d; |
| 415 |
< |
rv[1] = 1.0 - specjitter*rv[1]; |
| 416 |
< |
if (rv[1] <= FTINY) |
| 417 |
< |
d = 1.0; |
| 418 |
< |
else |
| 419 |
< |
d = sqrt(-log(rv[1]) / |
| 420 |
< |
(cosp*cosp/np->u_alpha2 + |
| 421 |
< |
sinp*sinp/np->v_alpha2)); |
| 422 |
< |
for (i = 0; i < 3; i++) |
| 423 |
< |
h[i] = np->pnorm[i] + |
| 424 |
< |
d*(cosp*np->u[i] + sinp*np->v[i]); |
| 425 |
< |
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
| 426 |
< |
for (i = 0; i < 3; i++) |
| 427 |
< |
sr.rdir[i] = r->rdir[i] + d*h[i]; |
| 428 |
< |
if (DOT(sr.rdir, r->ron) <= FTINY) /* penetration? */ |
| 429 |
< |
VCOPY(sr.rdir, np->vrefl); /* jitter no good */ |
| 430 |
< |
rayvalue(&sr); |
| 431 |
< |
multcolor(sr.rcol, np->scolor); |
| 432 |
< |
addcolor(r->rcol, sr.rcol); |
| 407 |
> |
for (niter = 0; niter < MAXITER; niter++) { |
| 408 |
> |
if (niter) |
| 409 |
> |
d = frandom(); |
| 410 |
> |
else |
| 411 |
> |
d = urand(ilhash(dimlist,ndims)+samplendx); |
| 412 |
> |
multisamp(rv, 2, d); |
| 413 |
> |
d = 2.0*PI * rv[0]; |
| 414 |
> |
cosp = tcos(d) * np->u_alpha; |
| 415 |
> |
sinp = tsin(d) * np->v_alpha; |
| 416 |
> |
d = sqrt(cosp*cosp + sinp*sinp); |
| 417 |
> |
cosp /= d; |
| 418 |
> |
sinp /= d; |
| 419 |
> |
rv[1] = 1.0 - specjitter*rv[1]; |
| 420 |
> |
if (rv[1] <= FTINY) |
| 421 |
> |
d = 1.0; |
| 422 |
> |
else |
| 423 |
> |
d = sqrt(-log(rv[1]) / |
| 424 |
> |
(cosp*cosp/(np->u_alpha*np->u_alpha) + |
| 425 |
> |
sinp*sinp/(np->v_alpha*np->v_alpha))); |
| 426 |
> |
for (i = 0; i < 3; i++) |
| 427 |
> |
h[i] = np->pnorm[i] + |
| 428 |
> |
d*(cosp*np->u[i] + sinp*np->v[i]); |
| 429 |
> |
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d); |
| 430 |
> |
for (i = 0; i < 3; i++) |
| 431 |
> |
sr.rdir[i] = r->rdir[i] + d*h[i]; |
| 432 |
> |
if (DOT(sr.rdir, r->ron) > FTINY) { |
| 433 |
> |
rayvalue(&sr); |
| 434 |
> |
multcolor(sr.rcol, np->scolor); |
| 435 |
> |
addcolor(r->rcol, sr.rcol); |
| 436 |
> |
break; |
| 437 |
> |
} |
| 438 |
> |
} |
| 439 |
|
ndims--; |
| 440 |
|
} |
| 441 |
|
/* compute transmission */ |
| 442 |
|
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN && |
| 443 |
|
rayorigin(&sr, r, SPECULAR, np->tspec) == 0) { |
| 444 |
|
dimlist[ndims++] = (int)np->mp; |
| 445 |
< |
d = urand(ilhash(dimlist,ndims)+1823+samplendx); |
| 446 |
< |
multisamp(rv, 2, d); |
| 447 |
< |
d = 2.0*PI * rv[0]; |
| 448 |
< |
cosp = cos(d); |
| 449 |
< |
sinp = sin(d); |
| 450 |
< |
rv[1] = 1.0 - specjitter*rv[1]; |
| 451 |
< |
if (rv[1] <= FTINY) |
| 452 |
< |
d = 1.0; |
| 453 |
< |
else |
| 454 |
< |
d = sqrt(-log(rv[1]) / |
| 455 |
< |
(cosp*cosp*4./np->u_alpha2 + |
| 456 |
< |
sinp*sinp*4./np->v_alpha2)); |
| 457 |
< |
for (i = 0; i < 3; i++) |
| 458 |
< |
sr.rdir[i] = np->prdir[i] + |
| 459 |
< |
d*(cosp*np->u[i] + sinp*np->v[i]); |
| 460 |
< |
if (DOT(sr.rdir, r->ron) < -FTINY) |
| 461 |
< |
normalize(sr.rdir); /* OK, normalize */ |
| 462 |
< |
else |
| 463 |
< |
VCOPY(sr.rdir, np->prdir); /* else no jitter */ |
| 464 |
< |
rayvalue(&sr); |
| 465 |
< |
scalecolor(sr.rcol, np->tspec); |
| 466 |
< |
multcolor(sr.rcol, np->mcolor); /* modify by color */ |
| 467 |
< |
addcolor(r->rcol, sr.rcol); |
| 445 |
> |
for (niter = 0; niter < MAXITER; niter++) { |
| 446 |
> |
if (niter) |
| 447 |
> |
d = frandom(); |
| 448 |
> |
else |
| 449 |
> |
d = urand(ilhash(dimlist,ndims)+1823+samplendx); |
| 450 |
> |
multisamp(rv, 2, d); |
| 451 |
> |
d = 2.0*PI * rv[0]; |
| 452 |
> |
cosp = tcos(d) * np->u_alpha; |
| 453 |
> |
sinp = tsin(d) * np->v_alpha; |
| 454 |
> |
d = sqrt(cosp*cosp + sinp*sinp); |
| 455 |
> |
cosp /= d; |
| 456 |
> |
sinp /= d; |
| 457 |
> |
rv[1] = 1.0 - specjitter*rv[1]; |
| 458 |
> |
if (rv[1] <= FTINY) |
| 459 |
> |
d = 1.0; |
| 460 |
> |
else |
| 461 |
> |
d = sqrt(-log(rv[1]) / |
| 462 |
> |
(cosp*cosp/(np->u_alpha*np->u_alpha) + |
| 463 |
> |
sinp*sinp/(np->v_alpha*np->v_alpha))); |
| 464 |
> |
for (i = 0; i < 3; i++) |
| 465 |
> |
sr.rdir[i] = np->prdir[i] + |
| 466 |
> |
d*(cosp*np->u[i] + sinp*np->v[i]); |
| 467 |
> |
if (DOT(sr.rdir, r->ron) < -FTINY) { |
| 468 |
> |
normalize(sr.rdir); /* OK, normalize */ |
| 469 |
> |
rayvalue(&sr); |
| 470 |
> |
scalecolor(sr.rcol, np->tspec); |
| 471 |
> |
multcolor(sr.rcol, np->mcolor); /* modify */ |
| 472 |
> |
addcolor(r->rcol, sr.rcol); |
| 473 |
> |
break; |
| 474 |
> |
} |
| 475 |
> |
} |
| 476 |
|
ndims--; |
| 477 |
|
} |
| 478 |
|
} |
