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/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
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#ifndef lint |
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static char SCCSid[] = "$SunId$ SGI"; |
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static const char RCSid[] = "$Id$"; |
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#endif |
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/* |
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* normal.c - shading function for normal materials. |
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* |
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* Later changes described in delta comments. |
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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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#include "otypes.h" |
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#include "random.h" |
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extern double specthresh; /* specular sampling threshold */ |
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extern double specjitter; /* specular sampling jitter */ |
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extern int backvis; /* back faces visible? */ |
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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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/* estimate of Fresnel function */ |
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#define FRESNE(ci) (exp(-6.0*(ci)) - 0.00247875217) |
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< |
static gaussamp(); |
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static void gaussamp(); |
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/* |
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* This routine implements the isotropic Gaussian |
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} NORMDAT; /* normal material data */ |
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static void |
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dirnorm(cval, np, ldir, omega) /* compute source contribution */ |
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COLOR cval; /* returned coefficient */ |
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register NORMDAT *np; /* material data */ |
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double omega; /* light source size */ |
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{ |
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double ldot; |
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double ldiff; |
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double dtmp, d2; |
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FVECT vtmp; |
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COLOR ctmp; |
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if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY) |
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return; /* wrong side */ |
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|
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if (ldot > FTINY && np->rdiff > FTINY) { |
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/* Fresnel estimate */ |
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ldiff = np->rdiff; |
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if (np->specfl & SP_PURE && (np->rspec > FTINY & ldiff > FTINY)) |
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ldiff *= 1. - FRESNE(fabs(ldot)); |
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if (ldot > FTINY && ldiff > FTINY) { |
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/* |
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* Compute and add diffuse reflected component to returned |
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* color. The diffuse reflected component will always be |
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* modified by the color of the material. |
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*/ |
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copycolor(ctmp, np->mcolor); |
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dtmp = ldot * omega * np->rdiff / PI; |
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dtmp = ldot * omega * ldiff / PI; |
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scalecolor(ctmp, dtmp); |
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addcolor(cval, ctmp); |
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} |
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} |
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int |
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m_normal(m, r) /* color a ray that hit something normal */ |
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register OBJREC *m; |
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register RAY *r; |
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{ |
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NORMDAT nd; |
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double fest; |
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double transtest, transdist; |
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double mirtest, mirdist; |
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int hastexture; |
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mirtest = transtest = 0; |
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mirdist = transdist = r->rot; |
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nd.rspec = m->oargs.farg[3]; |
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/* compute Fresnel approx. */ |
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if (nd.specfl & SP_PURE && nd.rspec > FTINY) { |
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fest = FRESNE(r->rod); |
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nd.rspec += fest*(1. - nd.rspec); |
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} else |
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fest = 0.; |
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/* compute transmission */ |
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if (m->otype == MAT_TRANS) { |
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nd.trans = m->oargs.farg[5]*(1.0 - nd.rspec); |
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if (nd.rspec > FTINY) { |
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nd.specfl |= SP_REFL; |
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/* compute specular color */ |
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if (m->otype == MAT_METAL) |
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if (m->otype != MAT_METAL) { |
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setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec); |
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} else if (fest > FTINY) { |
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d = nd.rspec*(1. - fest); |
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for (i = 0; i < 3; i++) |
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nd.scolor[i] = fest + nd.mcolor[i]*d; |
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} else { |
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copycolor(nd.scolor, nd.mcolor); |
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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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scalecolor(nd.scolor, nd.rspec); |
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} |
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/* check threshold */ |
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if (!(nd.specfl & SP_PURE) && specthresh >= nd.rspec-FTINY) |
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nd.specfl |= SP_RBLT; |
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} |
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|
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< |
static |
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static void |
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gaussamp(r, np) /* sample gaussian specular */ |
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RAY *r; |
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register NORMDAT *np; |
