| 1 |
greg |
1.1 |
#ifndef lint
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| 2 |
greg |
2.38 |
static const char RCSid[] = "$Id$";
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| 3 |
greg |
1.1 |
#endif
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| 4 |
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/*
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| 5 |
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* normal.c - shading function for normal materials.
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| 6 |
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*
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| 7 |
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* 8/19/85
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| 8 |
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* 12/19/85 - added stuff for metals.
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| 9 |
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* 6/26/87 - improved specular model.
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| 10 |
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* 9/28/87 - added model for translucent materials.
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| 11 |
greg |
2.2 |
* Later changes described in delta comments.
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| 12 |
greg |
1.1 |
*/
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| 13 |
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| 14 |
greg |
2.39 |
#include "copyright.h"
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| 15 |
greg |
2.38 |
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| 16 |
greg |
1.1 |
#include "ray.h"
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| 17 |
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| 18 |
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#include "otypes.h"
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| 19 |
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| 20 |
greg |
2.2 |
#include "random.h"
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| 21 |
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| 22 |
greg |
2.34 |
#ifndef MAXITER
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| 23 |
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#define MAXITER 10 /* maximum # specular ray attempts */
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| 24 |
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#endif
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| 25 |
greg |
2.38 |
/* estimate of Fresnel function */
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| 26 |
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#define FRESNE(ci) (exp(-6.0*(ci)) - 0.00247875217)
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| 27 |
greg |
2.34 |
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| 28 |
greg |
2.38 |
static void gaussamp();
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| 29 |
greg |
2.24 |
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| 30 |
greg |
1.1 |
/*
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| 31 |
greg |
2.22 |
* This routine implements the isotropic Gaussian
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| 32 |
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* model described by Ward in Siggraph `92 article.
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| 33 |
greg |
1.1 |
* We orient the surface towards the incoming ray, so a single
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| 34 |
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* surface can be used to represent an infinitely thin object.
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| 35 |
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*
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| 36 |
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* Arguments for MAT_PLASTIC and MAT_METAL are:
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| 37 |
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* red grn blu specular-frac. facet-slope
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| 38 |
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*
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| 39 |
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* Arguments for MAT_TRANS are:
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| 40 |
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* red grn blu rspec rough trans tspec
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| 41 |
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*/
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| 42 |
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greg |
2.2 |
/* specularity flags */
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| 44 |
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#define SP_REFL 01 /* has reflected specular component */
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| 45 |
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#define SP_TRAN 02 /* has transmitted specular */
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greg |
2.11 |
#define SP_PURE 04 /* purely specular (zero roughness) */
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| 47 |
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#define SP_FLAT 010 /* flat reflecting surface */
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| 48 |
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#define SP_RBLT 020 /* reflection below sample threshold */
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| 49 |
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#define SP_TBLT 040 /* transmission below threshold */
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| 50 |
greg |
1.1 |
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| 51 |
greg |
1.3 |
typedef struct {
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| 52 |
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OBJREC *mp; /* material pointer */
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greg |
2.16 |
RAY *rp; /* ray pointer */
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greg |
2.2 |
short specfl; /* specularity flags, defined above */
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| 55 |
greg |
1.1 |
COLOR mcolor; /* color of this material */
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| 56 |
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COLOR scolor; /* color of specular component */
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| 57 |
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FVECT vrefl; /* vector in direction of reflected ray */
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| 58 |
greg |
1.14 |
FVECT prdir; /* vector in transmitted direction */
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| 59 |
greg |
2.2 |
double alpha2; /* roughness squared */
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| 60 |
greg |
1.1 |
double rdiff, rspec; /* reflected specular, diffuse */
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| 61 |
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double trans; /* transmissivity */
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| 62 |
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double tdiff, tspec; /* transmitted specular, diffuse */
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| 63 |
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FVECT pnorm; /* perturbed surface normal */
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| 64 |
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double pdot; /* perturbed dot product */
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greg |
1.3 |
} NORMDAT; /* normal material data */
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| 68 |
greg |
2.38 |
static void
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| 69 |
greg |
1.3 |
dirnorm(cval, np, ldir, omega) /* compute source contribution */
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| 70 |
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COLOR cval; /* returned coefficient */
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| 71 |
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register NORMDAT *np; /* material data */
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| 72 |
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FVECT ldir; /* light source direction */
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| 73 |
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double omega; /* light source size */
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| 74 |
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{
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| 75 |
greg |
1.1 |
double ldot;
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| 76 |
greg |
2.38 |
double ldiff;
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| 77 |
greg |
2.16 |
double dtmp, d2;
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| 78 |
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FVECT vtmp;
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| 79 |
greg |
1.3 |
COLOR ctmp;
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| 81 |
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setcolor(cval, 0.0, 0.0, 0.0);
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| 82 |
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| 83 |
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ldot = DOT(np->pnorm, ldir);
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| 84 |
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| 85 |
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if (ldot < 0.0 ? np->trans <= FTINY : np->trans >= 1.0-FTINY)
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| 86 |
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return; /* wrong side */
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| 87 |
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| 88 |
greg |
2.38 |
/* Fresnel estimate */
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| 89 |
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ldiff = np->rdiff;
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| 90 |
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if (np->specfl & SP_PURE && (np->rspec > FTINY & ldiff > FTINY))
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| 91 |
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ldiff *= 1. - FRESNE(fabs(ldot));
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| 92 |
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| 93 |
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if (ldot > FTINY && ldiff > FTINY) {
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| 94 |
greg |
1.3 |
/*
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| 95 |
greg |
1.4 |
* Compute and add diffuse reflected component to returned
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| 96 |
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* color. The diffuse reflected component will always be
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| 97 |
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* modified by the color of the material.
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| 98 |
greg |
1.3 |
*/
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| 99 |
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copycolor(ctmp, np->mcolor);
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| 100 |
greg |
2.38 |
dtmp = ldot * omega * ldiff / PI;
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| 101 |
greg |
1.3 |
scalecolor(ctmp, dtmp);
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| 102 |
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addcolor(cval, ctmp);
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| 103 |
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}
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| 104 |
greg |
2.2 |
if (ldot > FTINY && (np->specfl&(SP_REFL|SP_PURE)) == SP_REFL) {
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| 105 |
greg |
1.3 |
/*
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| 106 |
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* Compute specular reflection coefficient using
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| 107 |
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* gaussian distribution model.
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| 108 |
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*/
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| 109 |
greg |
2.3 |
/* roughness */
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| 110 |
greg |
2.16 |
dtmp = np->alpha2;
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| 111 |
greg |
2.3 |
/* + source if flat */
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| 112 |
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if (np->specfl & SP_FLAT)
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| 113 |
greg |
2.16 |
dtmp += omega/(4.0*PI);
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| 114 |
greg |
2.23 |
/* half vector */
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| 115 |
greg |
2.18 |
vtmp[0] = ldir[0] - np->rp->rdir[0];
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| 116 |
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vtmp[1] = ldir[1] - np->rp->rdir[1];
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| 117 |
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vtmp[2] = ldir[2] - np->rp->rdir[2];
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| 118 |
greg |
2.16 |
d2 = DOT(vtmp, np->pnorm);
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| 119 |
greg |
2.23 |
d2 *= d2;
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| 120 |
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d2 = (DOT(vtmp,vtmp) - d2) / d2;
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| 121 |
greg |
1.3 |
/* gaussian */
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| 122 |
greg |
2.16 |
dtmp = exp(-d2/dtmp)/(4.*PI*dtmp);
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| 123 |
greg |
1.3 |
/* worth using? */
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| 124 |
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if (dtmp > FTINY) {
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| 125 |
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copycolor(ctmp, np->scolor);
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| 126 |
greg |
2.14 |
dtmp *= omega * sqrt(ldot/np->pdot);
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| 127 |
greg |
1.3 |
scalecolor(ctmp, dtmp);
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| 128 |
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addcolor(cval, ctmp);
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| 129 |
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}
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| 130 |
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}
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| 131 |
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if (ldot < -FTINY && np->tdiff > FTINY) {
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| 132 |
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/*
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| 133 |
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* Compute diffuse transmission.
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| 134 |
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*/
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| 135 |
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copycolor(ctmp, np->mcolor);
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| 136 |
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dtmp = -ldot * omega * np->tdiff / PI;
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| 137 |
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scalecolor(ctmp, dtmp);
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| 138 |
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addcolor(cval, ctmp);
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| 139 |
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}
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| 140 |
greg |
2.2 |
if (ldot < -FTINY && (np->specfl&(SP_TRAN|SP_PURE)) == SP_TRAN) {
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| 141 |
greg |
1.3 |
/*
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| 142 |
greg |
1.4 |
* Compute specular transmission. Specular transmission
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| 143 |
greg |
1.13 |
* is always modified by material color.
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| 144 |
greg |
1.3 |
*/
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| 145 |
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/* roughness + source */
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| 146 |
greg |
2.19 |
dtmp = np->alpha2 + omega/PI;
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| 147 |
greg |
1.3 |
/* gaussian */
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| 148 |
greg |
2.21 |
dtmp = exp((2.*DOT(np->prdir,ldir)-2.)/dtmp)/(PI*dtmp);
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| 149 |
greg |
1.3 |
/* worth using? */
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| 150 |
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if (dtmp > FTINY) {
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| 151 |
greg |
1.13 |
copycolor(ctmp, np->mcolor);
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| 152 |
greg |
2.18 |
dtmp *= np->tspec * omega * sqrt(-ldot/np->pdot);
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| 153 |
greg |
1.13 |
scalecolor(ctmp, dtmp);
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| 154 |
greg |
1.3 |
addcolor(cval, ctmp);
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| 155 |
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}
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| 156 |
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}
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| 157 |
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}
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| 158 |
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| 159 |
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| 160 |
greg |
2.38 |
int
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| 161 |
greg |
2.2 |
m_normal(m, r) /* color a ray that hit something normal */
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| 162 |
greg |
1.3 |
register OBJREC *m;
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| 163 |
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register RAY *r;
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| 164 |
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{
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| 165 |
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NORMDAT nd;
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| 166 |
greg |
2.38 |
double fest;
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| 167 |
greg |
1.9 |
double transtest, transdist;
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| 168 |
greg |
2.29 |
double mirtest, mirdist;
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| 169 |
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int hastexture;
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| 170 |
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double d;
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| 171 |
greg |
1.1 |
COLOR ctmp;
|
| 172 |
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register int i;
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| 173 |
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/* easy shadow test */
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| 174 |
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if (r->crtype & SHADOW && m->otype != MAT_TRANS)
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| 175 |
greg |
2.27 |
return(1);
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| 176 |
greg |
2.2 |
|
| 177 |
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if (m->oargs.nfargs != (m->otype == MAT_TRANS ? 7 : 5))
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| 178 |
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objerror(m, USER, "bad number of arguments");
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| 179 |
greg |
2.29 |
/* check for back side */
|
| 180 |
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if (r->rod < 0.0) {
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| 181 |
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if (!backvis && m->otype != MAT_TRANS) {
|
| 182 |
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raytrans(r);
|
| 183 |
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return(1);
|
| 184 |
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}
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| 185 |
greg |
2.40 |
raytexture(r, m->omod);
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| 186 |
greg |
2.29 |
flipsurface(r); /* reorient if backvis */
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| 187 |
greg |
2.40 |
} else
|
| 188 |
|
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raytexture(r, m->omod);
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| 189 |
greg |
1.3 |
nd.mp = m;
|
| 190 |
greg |
2.16 |
nd.rp = r;
|
| 191 |
greg |
1.1 |
/* get material color */
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| 192 |
greg |
1.3 |
setcolor(nd.mcolor, m->oargs.farg[0],
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| 193 |
greg |
1.1 |
m->oargs.farg[1],
|
| 194 |
|
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m->oargs.farg[2]);
|
| 195 |
|
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/* get roughness */
|
| 196 |
greg |
2.2 |
nd.specfl = 0;
|
| 197 |
greg |
1.3 |
nd.alpha2 = m->oargs.farg[4];
|
| 198 |
greg |
2.2 |
if ((nd.alpha2 *= nd.alpha2) <= FTINY)
|
| 199 |
|
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nd.specfl |= SP_PURE;
|
| 200 |
greg |
2.29 |
if (r->ro != NULL && isflat(r->ro->otype))
|
| 201 |
|
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nd.specfl |= SP_FLAT;
|
| 202 |
greg |
2.40 |
|
| 203 |
greg |
2.29 |
if (hastexture = DOT(r->pert,r->pert) > FTINY*FTINY)
|
| 204 |
|
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nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */
|
| 205 |
|
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else {
|
| 206 |
|
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VCOPY(nd.pnorm, r->ron);
|
| 207 |
|
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nd.pdot = r->rod;
|
| 208 |
|
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}
|
| 209 |
greg |
1.13 |
if (nd.pdot < .001)
|
| 210 |
|
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nd.pdot = .001; /* non-zero for dirnorm() */
|
| 211 |
greg |
1.3 |
multcolor(nd.mcolor, r->pcol); /* modify material color */
|
| 212 |
greg |
2.29 |
mirtest = transtest = 0;
|
| 213 |
|
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mirdist = transdist = r->rot;
|
| 214 |
greg |
2.30 |
nd.rspec = m->oargs.farg[3];
|
| 215 |
greg |
2.38 |
/* compute Fresnel approx. */
|
| 216 |
|
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if (nd.specfl & SP_PURE && nd.rspec > FTINY) {
|
| 217 |
|
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fest = FRESNE(r->rod);
|
| 218 |
|
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nd.rspec += fest*(1. - nd.rspec);
|
| 219 |
|
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} else
|
| 220 |
|
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fest = 0.;
|
| 221 |
greg |
1.3 |
/* compute transmission */
|
| 222 |
greg |
1.1 |
if (m->otype == MAT_TRANS) {
|
| 223 |
greg |
1.3 |
nd.trans = m->oargs.farg[5]*(1.0 - nd.rspec);
|
| 224 |
|
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nd.tspec = nd.trans * m->oargs.farg[6];
|
| 225 |
|
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nd.tdiff = nd.trans - nd.tspec;
|
| 226 |
greg |
2.2 |
if (nd.tspec > FTINY) {
|
| 227 |
|
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nd.specfl |= SP_TRAN;
|
| 228 |
greg |
2.5 |
/* check threshold */
|
| 229 |
greg |
2.25 |
if (!(nd.specfl & SP_PURE) &&
|
| 230 |
|
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specthresh >= nd.tspec-FTINY)
|
| 231 |
greg |
2.5 |
nd.specfl |= SP_TBLT;
|
| 232 |
greg |
2.29 |
if (!hastexture || r->crtype & SHADOW) {
|
| 233 |
greg |
2.2 |
VCOPY(nd.prdir, r->rdir);
|
| 234 |
|
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transtest = 2;
|
| 235 |
|
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} else {
|
| 236 |
|
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for (i = 0; i < 3; i++) /* perturb */
|
| 237 |
greg |
2.19 |
nd.prdir[i] = r->rdir[i] - r->pert[i];
|
| 238 |
greg |
2.7 |
if (DOT(nd.prdir, r->ron) < -FTINY)
|
| 239 |
|
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normalize(nd.prdir); /* OK */
|
| 240 |
|
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else
|
| 241 |
|
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VCOPY(nd.prdir, r->rdir);
|
| 242 |
greg |
2.2 |
}
|
| 243 |
greg |
1.14 |
}
|
| 244 |
greg |
1.1 |
} else
|
| 245 |
greg |
1.3 |
nd.tdiff = nd.tspec = nd.trans = 0.0;
|
| 246 |
greg |
1.1 |
/* transmitted ray */
|
| 247 |
gregl |
2.36 |
if ((nd.specfl&(SP_TRAN|SP_PURE|SP_TBLT)) == (SP_TRAN|SP_PURE)) {
|
| 248 |
greg |
1.3 |
RAY lr;
|
| 249 |
|
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if (rayorigin(&lr, r, TRANS, nd.tspec) == 0) {
|
| 250 |
greg |
1.14 |
VCOPY(lr.rdir, nd.prdir);
|
| 251 |
greg |
1.1 |
rayvalue(&lr);
|
| 252 |
greg |
1.3 |
scalecolor(lr.rcol, nd.tspec);
|
| 253 |
greg |
1.8 |
multcolor(lr.rcol, nd.mcolor); /* modified by color */
|
| 254 |
greg |
1.1 |
addcolor(r->rcol, lr.rcol);
|
| 255 |
greg |
1.9 |
transtest *= bright(lr.rcol);
|
| 256 |
|
|
transdist = r->rot + lr.rt;
|
| 257 |
greg |
1.1 |
}
|
| 258 |
greg |
2.11 |
} else
|
| 259 |
|
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transtest = 0;
|
| 260 |
greg |
2.2 |
|
| 261 |
greg |
2.29 |
if (r->crtype & SHADOW) { /* the rest is shadow */
|
| 262 |
|
|
r->rt = transdist;
|
| 263 |
greg |
2.27 |
return(1);
|
| 264 |
greg |
2.30 |
}
|
| 265 |
|
|
/* get specular reflection */
|
| 266 |
|
|
if (nd.rspec > FTINY) {
|
| 267 |
|
|
nd.specfl |= SP_REFL;
|
| 268 |
|
|
/* compute specular color */
|
| 269 |
greg |
2.38 |
if (m->otype != MAT_METAL) {
|
| 270 |
|
|
setcolor(nd.scolor, nd.rspec, nd.rspec, nd.rspec);
|
| 271 |
|
|
} else if (fest > FTINY) {
|
| 272 |
|
|
d = nd.rspec*(1. - fest);
|
| 273 |
|
|
for (i = 0; i < 3; i++)
|
| 274 |
|
|
nd.scolor[i] = fest + nd.mcolor[i]*d;
|
| 275 |
|
|
} else {
|
| 276 |
greg |
2.30 |
copycolor(nd.scolor, nd.mcolor);
|
| 277 |
greg |
2.38 |
scalecolor(nd.scolor, nd.rspec);
|
| 278 |
|
|
}
|
| 279 |
greg |
2.30 |
/* check threshold */
|
| 280 |
|
|
if (!(nd.specfl & SP_PURE) && specthresh >= nd.rspec-FTINY)
|
| 281 |
|
|
nd.specfl |= SP_RBLT;
|
| 282 |
|
|
/* compute reflected ray */
|
| 283 |
|
|
for (i = 0; i < 3; i++)
|
| 284 |
|
|
nd.vrefl[i] = r->rdir[i] + 2.*nd.pdot*nd.pnorm[i];
|
| 285 |
|
|
/* penetration? */
|
| 286 |
|
|
if (hastexture && DOT(nd.vrefl, r->ron) <= FTINY)
|
| 287 |
|
|
for (i = 0; i < 3; i++) /* safety measure */
|
| 288 |
|
|
nd.vrefl[i] = r->rdir[i] + 2.*r->rod*r->ron[i];
|
| 289 |
gregl |
2.36 |
}
|
| 290 |
|
|
/* reflected ray */
|
| 291 |
|
|
if ((nd.specfl&(SP_REFL|SP_PURE|SP_RBLT)) == (SP_REFL|SP_PURE)) {
|
| 292 |
|
|
RAY lr;
|
| 293 |
|
|
if (rayorigin(&lr, r, REFLECTED, nd.rspec) == 0) {
|
| 294 |
|
|
VCOPY(lr.rdir, nd.vrefl);
|
| 295 |
|
|
rayvalue(&lr);
|
| 296 |
|
|
multcolor(lr.rcol, nd.scolor);
|
| 297 |
|
|
addcolor(r->rcol, lr.rcol);
|
| 298 |
|
|
if (!hastexture && nd.specfl & SP_FLAT) {
|
| 299 |
|
|
mirtest = 2.*bright(lr.rcol);
|
| 300 |
|
|
mirdist = r->rot + lr.rt;
|
| 301 |
greg |
2.30 |
}
|
| 302 |
|
|
}
|
| 303 |
greg |
2.29 |
}
|
| 304 |
greg |
1.1 |
/* diffuse reflection */
|
| 305 |
greg |
1.3 |
nd.rdiff = 1.0 - nd.trans - nd.rspec;
|
| 306 |
greg |
1.1 |
|
| 307 |
greg |
2.2 |
if (nd.specfl & SP_PURE && nd.rdiff <= FTINY && nd.tdiff <= FTINY)
|
| 308 |
greg |
2.27 |
return(1); /* 100% pure specular */
|
| 309 |
greg |
2.3 |
|
| 310 |
gregl |
2.36 |
if (!(nd.specfl & SP_PURE))
|
| 311 |
|
|
gaussamp(r, &nd); /* checks *BLT flags */
|
| 312 |
greg |
2.2 |
|
| 313 |
greg |
1.3 |
if (nd.rdiff > FTINY) { /* ambient from this side */
|
| 314 |
greg |
2.31 |
ambient(ctmp, r, hastexture?nd.pnorm:r->ron);
|
| 315 |
greg |
2.5 |
if (nd.specfl & SP_RBLT)
|
| 316 |
|
|
scalecolor(ctmp, 1.0-nd.trans);
|
| 317 |
|
|
else
|
| 318 |
|
|
scalecolor(ctmp, nd.rdiff);
|
| 319 |
greg |
1.3 |
multcolor(ctmp, nd.mcolor); /* modified by material color */
|
| 320 |
greg |
1.2 |
addcolor(r->rcol, ctmp); /* add to returned color */
|
| 321 |
|
|
}
|
| 322 |
greg |
1.3 |
if (nd.tdiff > FTINY) { /* ambient from other side */
|
| 323 |
greg |
1.1 |
flipsurface(r);
|
| 324 |
greg |
2.32 |
if (hastexture) {
|
| 325 |
|
|
FVECT bnorm;
|
| 326 |
|
|
bnorm[0] = -nd.pnorm[0];
|
| 327 |
|
|
bnorm[1] = -nd.pnorm[1];
|
| 328 |
|
|
bnorm[2] = -nd.pnorm[2];
|
| 329 |
|
|
ambient(ctmp, r, bnorm);
|
| 330 |
|
|
} else
|
| 331 |
|
|
ambient(ctmp, r, r->ron);
|
| 332 |
greg |
2.5 |
if (nd.specfl & SP_TBLT)
|
| 333 |
|
|
scalecolor(ctmp, nd.trans);
|
| 334 |
|
|
else
|
| 335 |
|
|
scalecolor(ctmp, nd.tdiff);
|
| 336 |
greg |
1.13 |
multcolor(ctmp, nd.mcolor); /* modified by color */
|
| 337 |
greg |
1.1 |
addcolor(r->rcol, ctmp);
|
| 338 |
|
|
flipsurface(r);
|
| 339 |
|
|
}
|
| 340 |
greg |
1.3 |
/* add direct component */
|
| 341 |
|
|
direct(r, dirnorm, &nd);
|
| 342 |
greg |
1.9 |
/* check distance */
|
| 343 |
greg |
2.29 |
d = bright(r->rcol);
|
| 344 |
|
|
if (transtest > d)
|
| 345 |
greg |
1.9 |
r->rt = transdist;
|
| 346 |
greg |
2.29 |
else if (mirtest > d)
|
| 347 |
|
|
r->rt = mirdist;
|
| 348 |
greg |
2.27 |
|
| 349 |
|
|
return(1);
|
| 350 |
greg |
2.2 |
}
|
| 351 |
|
|
|
| 352 |
|
|
|
| 353 |
greg |
2.38 |
static void
|
| 354 |
greg |
2.2 |
gaussamp(r, np) /* sample gaussian specular */
|
| 355 |
|
|
RAY *r;
|
| 356 |
|
|
register NORMDAT *np;
|
| 357 |
|
|
{
|
| 358 |
|
|
RAY sr;
|
| 359 |
|
|
FVECT u, v, h;
|
| 360 |
|
|
double rv[2];
|
| 361 |
|
|
double d, sinp, cosp;
|
| 362 |
greg |
2.34 |
int niter;
|
| 363 |
greg |
2.2 |
register int i;
|
| 364 |
greg |
2.13 |
/* quick test */
|
| 365 |
|
|
if ((np->specfl & (SP_REFL|SP_RBLT)) != SP_REFL &&
|
| 366 |
|
|
(np->specfl & (SP_TRAN|SP_TBLT)) != SP_TRAN)
|
| 367 |
|
|
return;
|
| 368 |
greg |
2.2 |
/* set up sample coordinates */
|
| 369 |
|
|
v[0] = v[1] = v[2] = 0.0;
|
| 370 |
|
|
for (i = 0; i < 3; i++)
|
| 371 |
|
|
if (np->pnorm[i] < 0.6 && np->pnorm[i] > -0.6)
|
| 372 |
|
|
break;
|
| 373 |
|
|
v[i] = 1.0;
|
| 374 |
|
|
fcross(u, v, np->pnorm);
|
| 375 |
|
|
normalize(u);
|
| 376 |
|
|
fcross(v, np->pnorm, u);
|
| 377 |
|
|
/* compute reflection */
|
| 378 |
greg |
2.5 |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL &&
|
| 379 |
greg |
2.2 |
rayorigin(&sr, r, SPECULAR, np->rspec) == 0) {
|
| 380 |
|
|
dimlist[ndims++] = (int)np->mp;
|
| 381 |
greg |
2.34 |
for (niter = 0; niter < MAXITER; niter++) {
|
| 382 |
|
|
if (niter)
|
| 383 |
|
|
d = frandom();
|
| 384 |
|
|
else
|
| 385 |
|
|
d = urand(ilhash(dimlist,ndims)+samplendx);
|
| 386 |
|
|
multisamp(rv, 2, d);
|
| 387 |
|
|
d = 2.0*PI * rv[0];
|
| 388 |
gwlarson |
2.37 |
cosp = tcos(d);
|
| 389 |
|
|
sinp = tsin(d);
|
| 390 |
greg |
2.34 |
rv[1] = 1.0 - specjitter*rv[1];
|
| 391 |
|
|
if (rv[1] <= FTINY)
|
| 392 |
|
|
d = 1.0;
|
| 393 |
|
|
else
|
| 394 |
|
|
d = sqrt( np->alpha2 * -log(rv[1]) );
|
| 395 |
|
|
for (i = 0; i < 3; i++)
|
| 396 |
|
|
h[i] = np->pnorm[i] + d*(cosp*u[i] + sinp*v[i]);
|
| 397 |
|
|
d = -2.0 * DOT(h, r->rdir) / (1.0 + d*d);
|
| 398 |
|
|
for (i = 0; i < 3; i++)
|
| 399 |
|
|
sr.rdir[i] = r->rdir[i] + d*h[i];
|
| 400 |
|
|
if (DOT(sr.rdir, r->ron) > FTINY) {
|
| 401 |
|
|
rayvalue(&sr);
|
| 402 |
|
|
multcolor(sr.rcol, np->scolor);
|
| 403 |
|
|
addcolor(r->rcol, sr.rcol);
|
| 404 |
|
|
break;
|
| 405 |
|
|
}
|
| 406 |
|
|
}
|
| 407 |
greg |
2.2 |
ndims--;
|
| 408 |
|
|
}
|
| 409 |
|
|
/* compute transmission */
|
| 410 |
greg |
2.8 |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN &&
|
| 411 |
|
|
rayorigin(&sr, r, SPECULAR, np->tspec) == 0) {
|
| 412 |
|
|
dimlist[ndims++] = (int)np->mp;
|
| 413 |
greg |
2.34 |
for (niter = 0; niter < MAXITER; niter++) {
|
| 414 |
|
|
if (niter)
|
| 415 |
|
|
d = frandom();
|
| 416 |
|
|
else
|
| 417 |
|
|
d = urand(ilhash(dimlist,ndims)+1823+samplendx);
|
| 418 |
|
|
multisamp(rv, 2, d);
|
| 419 |
|
|
d = 2.0*PI * rv[0];
|
| 420 |
gwlarson |
2.37 |
cosp = tcos(d);
|
| 421 |
|
|
sinp = tsin(d);
|
| 422 |
greg |
2.34 |
rv[1] = 1.0 - specjitter*rv[1];
|
| 423 |
|
|
if (rv[1] <= FTINY)
|
| 424 |
|
|
d = 1.0;
|
| 425 |
|
|
else
|
| 426 |
gwlarson |
2.37 |
d = sqrt( np->alpha2 * -log(rv[1]) );
|
| 427 |
greg |
2.34 |
for (i = 0; i < 3; i++)
|
| 428 |
|
|
sr.rdir[i] = np->prdir[i] + d*(cosp*u[i] + sinp*v[i]);
|
| 429 |
|
|
if (DOT(sr.rdir, r->ron) < -FTINY) {
|
| 430 |
|
|
normalize(sr.rdir); /* OK, normalize */
|
| 431 |
|
|
rayvalue(&sr);
|
| 432 |
|
|
scalecolor(sr.rcol, np->tspec);
|
| 433 |
|
|
multcolor(sr.rcol, np->mcolor); /* modified */
|
| 434 |
|
|
addcolor(r->rcol, sr.rcol);
|
| 435 |
|
|
break;
|
| 436 |
|
|
}
|
| 437 |
|
|
}
|
| 438 |
greg |
2.8 |
ndims--;
|
| 439 |
|
|
}
|
| 440 |
greg |
1.1 |
}
|
