| 1 |
greg |
2.1 |
#ifndef lint
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| 2 |
greg |
2.62 |
static const char RCSid[] = "$Id: aniso.c,v 2.61 2015/09/02 18:59:01 greg Exp $";
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| 3 |
greg |
2.1 |
#endif
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| 4 |
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/*
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| 5 |
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* Shading functions for anisotropic materials.
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| 6 |
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*/
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| 7 |
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| 8 |
greg |
2.35 |
#include "copyright.h"
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| 9 |
greg |
2.34 |
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| 10 |
greg |
2.1 |
#include "ray.h"
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| 11 |
greg |
2.40 |
#include "ambient.h"
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| 12 |
greg |
2.1 |
#include "otypes.h"
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| 13 |
schorsch |
2.41 |
#include "rtotypes.h"
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| 14 |
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#include "source.h"
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greg |
2.1 |
#include "func.h"
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| 16 |
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#include "random.h"
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| 17 |
greg |
2.61 |
#include "pmapmat.h"
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| 18 |
greg |
2.1 |
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| 19 |
greg |
2.32 |
#ifndef MAXITER
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| 20 |
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#define MAXITER 10 /* maximum # specular ray attempts */
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| 21 |
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#endif
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| 22 |
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| 23 |
greg |
2.1 |
/*
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| 24 |
greg |
2.22 |
* This routine implements the anisotropic Gaussian
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| 25 |
greg |
2.54 |
* model described by Ward in Siggraph `92 article, updated with
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| 26 |
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* normalization and sampling adjustments due to Geisler-Moroder and Duer.
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| 27 |
greg |
2.1 |
* We orient the surface towards the incoming ray, so a single
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| 28 |
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* surface can be used to represent an infinitely thin object.
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| 29 |
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*
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| 30 |
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* Arguments for MAT_PLASTIC2 and MAT_METAL2 are:
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* 4+ ux uy uz funcfile [transform...]
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| 32 |
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* 0
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| 33 |
greg |
2.54 |
* 6 red grn blu specular-frac. u-rough v-rough
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greg |
2.1 |
*
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| 35 |
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* Real arguments for MAT_TRANS2 are:
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| 36 |
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* 8 red grn blu rspec u-rough v-rough trans tspec
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| 37 |
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*/
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| 38 |
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| 39 |
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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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greg |
2.10 |
#define SP_FLAT 04 /* reflecting surface is flat */
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#define SP_RBLT 010 /* reflection below sample threshold */
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#define SP_TBLT 020 /* transmission below threshold */
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greg |
2.1 |
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typedef struct {
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greg |
2.2 |
OBJREC *mp; /* material pointer */
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greg |
2.1 |
RAY *rp; /* ray pointer */
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short specfl; /* specularity flags, defined above */
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greg |
2.62 |
SCOLOR mcolor; /* color of this material */
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SCOLOR scolor; /* color of specular component */
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greg |
2.6 |
FVECT vrefl; /* vector in reflected direction */
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greg |
2.1 |
FVECT prdir; /* vector in transmitted direction */
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FVECT u, v; /* u and v vectors orienting anisotropy */
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greg |
2.18 |
double u_alpha; /* u roughness */
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double v_alpha; /* v roughness */
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greg |
2.1 |
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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FVECT pnorm; /* perturbed surface normal */
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double pdot; /* perturbed dot product */
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} ANISODAT; /* anisotropic material data */
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greg |
2.55 |
static void getacoords(ANISODAT *np);
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static void agaussamp(ANISODAT *np);
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greg |
2.34 |
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greg |
2.1 |
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greg |
2.34 |
static void
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schorsch |
2.41 |
diraniso( /* compute source contribution */
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greg |
2.62 |
SCOLOR scval, /* returned coefficient */
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greg |
2.54 |
void *nnp, /* material data */
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schorsch |
2.41 |
FVECT ldir, /* light source direction */
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double omega /* light source size */
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)
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greg |
2.1 |
{
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greg |
2.54 |
ANISODAT *np = nnp;
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greg |
2.1 |
double ldot;
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greg |
2.16 |
double dtmp, dtmp1, dtmp2;
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greg |
2.1 |
FVECT h;
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double au2, av2;
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greg |
2.62 |
SCOLOR sctmp;
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greg |
2.1 |
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greg |
2.62 |
scolorblack(scval);
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greg |
2.1 |
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ldot = DOT(np->pnorm, ldir);
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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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greg |
2.54 |
if ((ldot > FTINY) & (np->rdiff > FTINY)) {
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greg |
2.1 |
/*
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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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greg |
2.62 |
copyscolor(sctmp, np->mcolor);
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greg |
2.42 |
dtmp = ldot * omega * np->rdiff * (1.0/PI);
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greg |
2.62 |
scalescolor(sctmp, dtmp);
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saddscolor(scval, sctmp);
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greg |
2.1 |
}
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greg |
2.58 |
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if ((ldot < -FTINY) & (np->tdiff > FTINY)) {
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/*
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* Compute diffuse transmission.
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*/
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greg |
2.62 |
copyscolor(sctmp, np->mcolor);
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greg |
2.58 |
dtmp = -ldot * omega * np->tdiff * (1.0/PI);
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greg |
2.62 |
scalescolor(sctmp, dtmp);
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saddscolor(scval, sctmp);
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greg |
2.58 |
}
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greg |
2.61 |
if (ambRayInPmap(np->rp))
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| 113 |
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return; /* specular accounted for in photon map */
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greg |
2.57 |
if (ldot > FTINY && np->specfl&SP_REFL) {
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greg |
2.1 |
/*
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* Compute specular reflection coefficient using
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greg |
2.46 |
* anisotropic Gaussian distribution model.
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greg |
2.1 |
*/
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| 120 |
greg |
2.2 |
/* add source width if flat */
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if (np->specfl & SP_FLAT)
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greg |
2.42 |
au2 = av2 = omega * (0.25/PI);
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greg |
2.2 |
else
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| 124 |
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au2 = av2 = 0.0;
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greg |
2.18 |
au2 += np->u_alpha*np->u_alpha;
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av2 += np->v_alpha*np->v_alpha;
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greg |
2.1 |
/* half vector */
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greg |
2.54 |
VSUB(h, ldir, np->rp->rdir);
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greg |
2.1 |
/* ellipse */
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greg |
2.16 |
dtmp1 = DOT(np->u, h);
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| 131 |
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dtmp1 *= dtmp1 / au2;
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greg |
2.1 |
dtmp2 = DOT(np->v, h);
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dtmp2 *= dtmp2 / av2;
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greg |
2.46 |
/* new W-G-M-D model */
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greg |
2.23 |
dtmp = DOT(np->pnorm, h);
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greg |
2.46 |
dtmp *= dtmp;
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dtmp1 = (dtmp1 + dtmp2) / dtmp;
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| 138 |
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dtmp = exp(-dtmp1) * DOT(h,h) /
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| 139 |
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(PI * dtmp*dtmp * sqrt(au2*av2));
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greg |
2.1 |
/* worth using? */
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| 141 |
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if (dtmp > FTINY) {
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greg |
2.62 |
copyscolor(sctmp, np->scolor);
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greg |
2.46 |
dtmp *= ldot * omega;
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greg |
2.62 |
scalescolor(sctmp, dtmp);
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saddscolor(scval, sctmp);
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| 146 |
greg |
2.1 |
}
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| 147 |
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}
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greg |
2.58 |
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| 149 |
greg |
2.57 |
if (ldot < -FTINY && np->specfl&SP_TRAN) {
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| 150 |
greg |
2.1 |
/*
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* Compute specular transmission. Specular transmission
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* is always modified by material color.
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| 153 |
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*/
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| 154 |
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/* roughness + source */
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greg |
2.42 |
au2 = av2 = omega * (1.0/PI);
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greg |
2.18 |
au2 += np->u_alpha*np->u_alpha;
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| 157 |
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av2 += np->v_alpha*np->v_alpha;
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| 158 |
greg |
2.16 |
/* "half vector" */
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| 159 |
greg |
2.54 |
VSUB(h, ldir, np->prdir);
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greg |
2.19 |
dtmp = DOT(h,h);
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| 161 |
greg |
2.16 |
if (dtmp > FTINY*FTINY) {
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| 162 |
greg |
2.19 |
dtmp1 = DOT(h,np->pnorm);
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| 163 |
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dtmp = 1.0 - dtmp1*dtmp1/dtmp;
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| 164 |
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if (dtmp > FTINY*FTINY) {
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| 165 |
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dtmp1 = DOT(h,np->u);
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greg |
2.23 |
dtmp1 *= dtmp1 / au2;
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| 167 |
greg |
2.19 |
dtmp2 = DOT(h,np->v);
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| 168 |
greg |
2.23 |
dtmp2 *= dtmp2 / av2;
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greg |
2.19 |
dtmp = (dtmp1 + dtmp2) / dtmp;
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| 170 |
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}
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greg |
2.16 |
} else
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| 172 |
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dtmp = 0.0;
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greg |
2.46 |
/* Gaussian */
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| 174 |
greg |
2.44 |
dtmp = exp(-dtmp) * (1.0/PI) * sqrt(-ldot/(np->pdot*au2*av2));
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| 175 |
greg |
2.1 |
/* worth using? */
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| 176 |
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if (dtmp > FTINY) {
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| 177 |
greg |
2.62 |
copyscolor(sctmp, np->mcolor);
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| 178 |
greg |
2.16 |
dtmp *= np->tspec * omega;
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| 179 |
greg |
2.62 |
scalescolor(sctmp, dtmp);
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| 180 |
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saddscolor(scval, sctmp);
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greg |
2.1 |
}
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| 182 |
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}
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| 183 |
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}
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| 184 |
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| 185 |
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| 186 |
greg |
2.54 |
int
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| 187 |
schorsch |
2.41 |
m_aniso( /* shade ray that hit something anisotropic */
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| 188 |
greg |
2.54 |
OBJREC *m,
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| 189 |
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RAY *r
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| 190 |
schorsch |
2.41 |
)
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| 191 |
greg |
2.1 |
{
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| 192 |
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ANISODAT nd;
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| 193 |
greg |
2.62 |
SCOLOR sctmp;
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| 194 |
greg |
2.54 |
int i;
|
| 195 |
greg |
2.1 |
/* easy shadow test */
|
| 196 |
greg |
2.10 |
if (r->crtype & SHADOW)
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| 197 |
greg |
2.27 |
return(1);
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| 198 |
greg |
2.1 |
|
| 199 |
|
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if (m->oargs.nfargs != (m->otype == MAT_TRANS2 ? 8 : 6))
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| 200 |
|
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objerror(m, USER, "bad number of real arguments");
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| 201 |
greg |
2.36 |
/* check for back side */
|
| 202 |
|
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if (r->rod < 0.0) {
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| 203 |
greg |
2.56 |
if (!backvis) {
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| 204 |
greg |
2.36 |
raytrans(r);
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| 205 |
|
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return(1);
|
| 206 |
|
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}
|
| 207 |
|
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raytexture(r, m->omod);
|
| 208 |
|
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flipsurface(r); /* reorient if backvis */
|
| 209 |
|
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} else
|
| 210 |
|
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raytexture(r, m->omod);
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| 211 |
|
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/* get material color */
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| 212 |
greg |
2.2 |
nd.mp = m;
|
| 213 |
greg |
2.1 |
nd.rp = r;
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| 214 |
greg |
2.62 |
setscolor(nd.mcolor, m->oargs.farg[0],
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| 215 |
greg |
2.1 |
m->oargs.farg[1],
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| 216 |
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m->oargs.farg[2]);
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| 217 |
|
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/* get roughness */
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| 218 |
|
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nd.specfl = 0;
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| 219 |
greg |
2.18 |
nd.u_alpha = m->oargs.farg[4];
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| 220 |
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nd.v_alpha = m->oargs.farg[5];
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| 221 |
greg |
2.54 |
if ((nd.u_alpha <= FTINY) | (nd.v_alpha <= FTINY))
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| 222 |
greg |
2.10 |
objerror(m, USER, "roughness too small");
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| 223 |
greg |
2.36 |
|
| 224 |
greg |
2.1 |
nd.pdot = raynormal(nd.pnorm, r); /* perturb normal */
|
| 225 |
|
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if (nd.pdot < .001)
|
| 226 |
|
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nd.pdot = .001; /* non-zero for diraniso() */
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| 227 |
greg |
2.62 |
smultscolor(nd.mcolor, r->pcol); /* modify material color */
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| 228 |
greg |
2.1 |
/* get specular component */
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| 229 |
|
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if ((nd.rspec = m->oargs.farg[3]) > FTINY) {
|
| 230 |
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nd.specfl |= SP_REFL;
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| 231 |
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/* compute specular color */
|
| 232 |
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if (m->otype == MAT_METAL2)
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| 233 |
greg |
2.62 |
copyscolor(nd.scolor, nd.mcolor);
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| 234 |
greg |
2.1 |
else
|
| 235 |
greg |
2.62 |
setscolor(nd.scolor, 1.0, 1.0, 1.0);
|
| 236 |
|
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scalescolor(nd.scolor, nd.rspec);
|
| 237 |
greg |
2.4 |
/* check threshold */
|
| 238 |
greg |
2.25 |
if (specthresh >= nd.rspec-FTINY)
|
| 239 |
greg |
2.4 |
nd.specfl |= SP_RBLT;
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| 240 |
greg |
2.6 |
/* compute refl. direction */
|
| 241 |
greg |
2.47 |
VSUM(nd.vrefl, r->rdir, nd.pnorm, 2.0*nd.pdot);
|
| 242 |
greg |
2.6 |
if (DOT(nd.vrefl, r->ron) <= FTINY) /* penetration? */
|
| 243 |
greg |
2.47 |
VSUM(nd.vrefl, r->rdir, r->ron, 2.0*r->rod);
|
| 244 |
greg |
2.1 |
}
|
| 245 |
|
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/* compute transmission */
|
| 246 |
greg |
2.16 |
if (m->otype == MAT_TRANS2) {
|
| 247 |
greg |
2.1 |
nd.trans = m->oargs.farg[6]*(1.0 - nd.rspec);
|
| 248 |
|
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nd.tspec = nd.trans * m->oargs.farg[7];
|
| 249 |
|
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nd.tdiff = nd.trans - nd.tspec;
|
| 250 |
|
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if (nd.tspec > FTINY) {
|
| 251 |
|
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nd.specfl |= SP_TRAN;
|
| 252 |
greg |
2.4 |
/* check threshold */
|
| 253 |
greg |
2.25 |
if (specthresh >= nd.tspec-FTINY)
|
| 254 |
greg |
2.4 |
nd.specfl |= SP_TBLT;
|
| 255 |
greg |
2.10 |
if (DOT(r->pert,r->pert) <= FTINY*FTINY) {
|
| 256 |
greg |
2.1 |
VCOPY(nd.prdir, r->rdir);
|
| 257 |
|
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} else {
|
| 258 |
|
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for (i = 0; i < 3; i++) /* perturb */
|
| 259 |
greg |
2.17 |
nd.prdir[i] = r->rdir[i] - r->pert[i];
|
| 260 |
greg |
2.6 |
if (DOT(nd.prdir, r->ron) < -FTINY)
|
| 261 |
|
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normalize(nd.prdir); /* OK */
|
| 262 |
|
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else
|
| 263 |
|
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VCOPY(nd.prdir, r->rdir);
|
| 264 |
greg |
2.1 |
}
|
| 265 |
|
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}
|
| 266 |
|
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} else
|
| 267 |
|
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nd.tdiff = nd.tspec = nd.trans = 0.0;
|
| 268 |
|
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|
| 269 |
|
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/* diffuse reflection */
|
| 270 |
|
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nd.rdiff = 1.0 - nd.trans - nd.rspec;
|
| 271 |
|
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|
| 272 |
greg |
2.39 |
if (r->ro != NULL && isflat(r->ro->otype))
|
| 273 |
greg |
2.4 |
nd.specfl |= SP_FLAT;
|
| 274 |
|
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|
| 275 |
greg |
2.55 |
getacoords(&nd); /* set up coordinates */
|
| 276 |
greg |
2.1 |
|
| 277 |
greg |
2.60 |
if (nd.specfl & (SP_REFL|SP_TRAN))
|
| 278 |
greg |
2.55 |
agaussamp(&nd);
|
| 279 |
greg |
2.1 |
|
| 280 |
|
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if (nd.rdiff > FTINY) { /* ambient from this side */
|
| 281 |
greg |
2.62 |
copyscolor(sctmp, nd.mcolor); /* modified by material color */
|
| 282 |
|
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scalescolor(sctmp, nd.rdiff);
|
| 283 |
greg |
2.52 |
if (nd.specfl & SP_RBLT) /* add in specular as well? */
|
| 284 |
greg |
2.62 |
saddscolor(sctmp, nd.scolor);
|
| 285 |
|
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multambient(sctmp, r, nd.pnorm);
|
| 286 |
|
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saddscolor(r->rcol, sctmp); /* add to returned color */
|
| 287 |
greg |
2.1 |
}
|
| 288 |
greg |
2.58 |
|
| 289 |
greg |
2.1 |
if (nd.tdiff > FTINY) { /* ambient from other side */
|
| 290 |
greg |
2.31 |
FVECT bnorm;
|
| 291 |
|
|
|
| 292 |
greg |
2.1 |
flipsurface(r);
|
| 293 |
greg |
2.31 |
bnorm[0] = -nd.pnorm[0];
|
| 294 |
|
|
bnorm[1] = -nd.pnorm[1];
|
| 295 |
|
|
bnorm[2] = -nd.pnorm[2];
|
| 296 |
greg |
2.62 |
copyscolor(sctmp, nd.mcolor); /* modified by color */
|
| 297 |
|
|
if (nd.specfl & SP_TBLT) {
|
| 298 |
|
|
scalescolor(sctmp, nd.trans);
|
| 299 |
|
|
} else {
|
| 300 |
|
|
scalescolor(sctmp, nd.tdiff);
|
| 301 |
|
|
}
|
| 302 |
|
|
multambient(sctmp, r, bnorm);
|
| 303 |
|
|
saddscolor(r->rcol, sctmp);
|
| 304 |
greg |
2.1 |
flipsurface(r);
|
| 305 |
|
|
}
|
| 306 |
|
|
/* add direct component */
|
| 307 |
|
|
direct(r, diraniso, &nd);
|
| 308 |
greg |
2.27 |
|
| 309 |
|
|
return(1);
|
| 310 |
greg |
2.1 |
}
|
| 311 |
|
|
|
| 312 |
greg |
2.34 |
static void
|
| 313 |
schorsch |
2.41 |
getacoords( /* set up coordinate system */
|
| 314 |
greg |
2.54 |
ANISODAT *np
|
| 315 |
schorsch |
2.41 |
)
|
| 316 |
greg |
2.1 |
{
|
| 317 |
greg |
2.54 |
MFUNC *mf;
|
| 318 |
|
|
int i;
|
| 319 |
greg |
2.1 |
|
| 320 |
|
|
mf = getfunc(np->mp, 3, 0x7, 1);
|
| 321 |
greg |
2.55 |
setfunc(np->mp, np->rp);
|
| 322 |
greg |
2.1 |
errno = 0;
|
| 323 |
|
|
for (i = 0; i < 3; i++)
|
| 324 |
|
|
np->u[i] = evalue(mf->ep[i]);
|
| 325 |
greg |
2.57 |
if ((errno == EDOM) | (errno == ERANGE))
|
| 326 |
|
|
np->u[0] = np->u[1] = np->u[2] = 0.0;
|
| 327 |
greg |
2.53 |
if (mf->fxp != &unitxf)
|
| 328 |
|
|
multv3(np->u, np->u, mf->fxp->xfm);
|
| 329 |
greg |
2.1 |
fcross(np->v, np->pnorm, np->u);
|
| 330 |
|
|
if (normalize(np->v) == 0.0) {
|
| 331 |
greg |
2.57 |
if (fabs(np->u_alpha - np->v_alpha) > 0.001)
|
| 332 |
|
|
objerror(np->mp, WARNING, "illegal orientation vector");
|
| 333 |
greg |
2.59 |
getperpendicular(np->u, np->pnorm, 1); /* punting */
|
| 334 |
greg |
2.57 |
fcross(np->v, np->pnorm, np->u);
|
| 335 |
|
|
np->u_alpha = np->v_alpha = sqrt( 0.5 *
|
| 336 |
|
|
(np->u_alpha*np->u_alpha + np->v_alpha*np->v_alpha) );
|
| 337 |
|
|
} else
|
| 338 |
|
|
fcross(np->u, np->v, np->pnorm);
|
| 339 |
greg |
2.1 |
}
|
| 340 |
|
|
|
| 341 |
|
|
|
| 342 |
greg |
2.34 |
static void
|
| 343 |
greg |
2.46 |
agaussamp( /* sample anisotropic Gaussian specular */
|
| 344 |
greg |
2.54 |
ANISODAT *np
|
| 345 |
schorsch |
2.41 |
)
|
| 346 |
greg |
2.1 |
{
|
| 347 |
|
|
RAY sr;
|
| 348 |
|
|
FVECT h;
|
| 349 |
|
|
double rv[2];
|
| 350 |
|
|
double d, sinp, cosp;
|
| 351 |
greg |
2.62 |
SCOLOR scol;
|
| 352 |
greg |
2.50 |
int maxiter, ntrials, nstarget, nstaken;
|
| 353 |
greg |
2.54 |
int i;
|
| 354 |
greg |
2.1 |
/* compute reflection */
|
| 355 |
greg |
2.4 |
if ((np->specfl & (SP_REFL|SP_RBLT)) == SP_REFL &&
|
| 356 |
greg |
2.55 |
rayorigin(&sr, SPECULAR, np->rp, np->scolor) == 0) {
|
| 357 |
greg |
2.50 |
nstarget = 1;
|
| 358 |
greg |
2.47 |
if (specjitter > 1.5) { /* multiple samples? */
|
| 359 |
greg |
2.55 |
nstarget = specjitter*np->rp->rweight + .5;
|
| 360 |
greg |
2.50 |
if (sr.rweight <= minweight*nstarget)
|
| 361 |
|
|
nstarget = sr.rweight/minweight;
|
| 362 |
|
|
if (nstarget > 1) {
|
| 363 |
|
|
d = 1./nstarget;
|
| 364 |
|
|
scalecolor(sr.rcoef, d);
|
| 365 |
greg |
2.48 |
sr.rweight *= d;
|
| 366 |
greg |
2.47 |
} else
|
| 367 |
greg |
2.50 |
nstarget = 1;
|
| 368 |
greg |
2.47 |
}
|
| 369 |
greg |
2.62 |
scolorblack(scol);
|
| 370 |
greg |
2.51 |
dimlist[ndims++] = (int)(size_t)np->mp;
|
| 371 |
greg |
2.50 |
maxiter = MAXITER*nstarget;
|
| 372 |
|
|
for (nstaken = ntrials = 0; nstaken < nstarget &&
|
| 373 |
|
|
ntrials < maxiter; ntrials++) {
|
| 374 |
|
|
if (ntrials)
|
| 375 |
greg |
2.32 |
d = frandom();
|
| 376 |
|
|
else
|
| 377 |
|
|
d = urand(ilhash(dimlist,ndims)+samplendx);
|
| 378 |
|
|
multisamp(rv, 2, d);
|
| 379 |
|
|
d = 2.0*PI * rv[0];
|
| 380 |
gwlarson |
2.33 |
cosp = tcos(d) * np->u_alpha;
|
| 381 |
|
|
sinp = tsin(d) * np->v_alpha;
|
| 382 |
greg |
2.47 |
d = 1./sqrt(cosp*cosp + sinp*sinp);
|
| 383 |
|
|
cosp *= d;
|
| 384 |
|
|
sinp *= d;
|
| 385 |
|
|
if ((0. <= specjitter) & (specjitter < 1.))
|
| 386 |
|
|
rv[1] = 1.0 - specjitter*rv[1];
|
| 387 |
greg |
2.32 |
if (rv[1] <= FTINY)
|
| 388 |
|
|
d = 1.0;
|
| 389 |
|
|
else
|
| 390 |
|
|
d = sqrt(-log(rv[1]) /
|
| 391 |
|
|
(cosp*cosp/(np->u_alpha*np->u_alpha) +
|
| 392 |
|
|
sinp*sinp/(np->v_alpha*np->v_alpha)));
|
| 393 |
|
|
for (i = 0; i < 3; i++)
|
| 394 |
|
|
h[i] = np->pnorm[i] +
|
| 395 |
|
|
d*(cosp*np->u[i] + sinp*np->v[i]);
|
| 396 |
greg |
2.55 |
d = -2.0 * DOT(h, np->rp->rdir) / (1.0 + d*d);
|
| 397 |
|
|
VSUM(sr.rdir, np->rp->rdir, h, d);
|
| 398 |
greg |
2.50 |
/* sample rejection test */
|
| 399 |
greg |
2.55 |
if ((d = DOT(sr.rdir, np->rp->ron)) <= FTINY)
|
| 400 |
greg |
2.47 |
continue;
|
| 401 |
|
|
checknorm(sr.rdir);
|
| 402 |
greg |
2.50 |
if (nstarget > 1) { /* W-G-M-D adjustment */
|
| 403 |
|
|
if (nstaken) rayclear(&sr);
|
| 404 |
|
|
rayvalue(&sr);
|
| 405 |
greg |
2.55 |
d = 2./(1. + np->rp->rod/d);
|
| 406 |
greg |
2.62 |
scalescolor(sr.rcol, d);
|
| 407 |
|
|
saddscolor(scol, sr.rcol);
|
| 408 |
greg |
2.50 |
} else {
|
| 409 |
|
|
rayvalue(&sr);
|
| 410 |
greg |
2.62 |
smultscolor(sr.rcol, sr.rcoef);
|
| 411 |
|
|
saddscolor(np->rp->rcol, sr.rcol);
|
| 412 |
greg |
2.32 |
}
|
| 413 |
greg |
2.50 |
++nstaken;
|
| 414 |
|
|
}
|
| 415 |
|
|
if (nstarget > 1) { /* final W-G-M-D weighting */
|
| 416 |
greg |
2.62 |
smultscolor(scol, sr.rcoef);
|
| 417 |
greg |
2.50 |
d = (double)nstarget/ntrials;
|
| 418 |
greg |
2.62 |
scalescolor(scol, d);
|
| 419 |
|
|
saddscolor(np->rp->rcol, scol);
|
| 420 |
greg |
2.32 |
}
|
| 421 |
greg |
2.1 |
ndims--;
|
| 422 |
|
|
}
|
| 423 |
|
|
/* compute transmission */
|
| 424 |
greg |
2.62 |
copyscolor(sr.rcoef, np->mcolor); /* modify by material color */
|
| 425 |
|
|
scalescolor(sr.rcoef, np->tspec);
|
| 426 |
greg |
2.7 |
if ((np->specfl & (SP_TRAN|SP_TBLT)) == SP_TRAN &&
|
| 427 |
greg |
2.55 |
rayorigin(&sr, SPECULAR, np->rp, sr.rcoef) == 0) {
|
| 428 |
greg |
2.50 |
nstarget = 1;
|
| 429 |
greg |
2.47 |
if (specjitter > 1.5) { /* multiple samples? */
|
| 430 |
greg |
2.55 |
nstarget = specjitter*np->rp->rweight + .5;
|
| 431 |
greg |
2.50 |
if (sr.rweight <= minweight*nstarget)
|
| 432 |
|
|
nstarget = sr.rweight/minweight;
|
| 433 |
|
|
if (nstarget > 1) {
|
| 434 |
|
|
d = 1./nstarget;
|
| 435 |
greg |
2.48 |
scalecolor(sr.rcoef, d);
|
| 436 |
|
|
sr.rweight *= d;
|
| 437 |
greg |
2.47 |
} else
|
| 438 |
greg |
2.50 |
nstarget = 1;
|
| 439 |
greg |
2.47 |
}
|
| 440 |
greg |
2.51 |
dimlist[ndims++] = (int)(size_t)np->mp;
|
| 441 |
greg |
2.50 |
maxiter = MAXITER*nstarget;
|
| 442 |
|
|
for (nstaken = ntrials = 0; nstaken < nstarget &&
|
| 443 |
|
|
ntrials < maxiter; ntrials++) {
|
| 444 |
|
|
if (ntrials)
|
| 445 |
greg |
2.32 |
d = frandom();
|
| 446 |
|
|
else
|
| 447 |
|
|
d = urand(ilhash(dimlist,ndims)+1823+samplendx);
|
| 448 |
|
|
multisamp(rv, 2, d);
|
| 449 |
|
|
d = 2.0*PI * rv[0];
|
| 450 |
gwlarson |
2.33 |
cosp = tcos(d) * np->u_alpha;
|
| 451 |
|
|
sinp = tsin(d) * np->v_alpha;
|
| 452 |
greg |
2.47 |
d = 1./sqrt(cosp*cosp + sinp*sinp);
|
| 453 |
|
|
cosp *= d;
|
| 454 |
|
|
sinp *= d;
|
| 455 |
|
|
if ((0. <= specjitter) & (specjitter < 1.))
|
| 456 |
|
|
rv[1] = 1.0 - specjitter*rv[1];
|
| 457 |
greg |
2.32 |
if (rv[1] <= FTINY)
|
| 458 |
|
|
d = 1.0;
|
| 459 |
|
|
else
|
| 460 |
|
|
d = sqrt(-log(rv[1]) /
|
| 461 |
|
|
(cosp*cosp/(np->u_alpha*np->u_alpha) +
|
| 462 |
gwlarson |
2.33 |
sinp*sinp/(np->v_alpha*np->v_alpha)));
|
| 463 |
greg |
2.32 |
for (i = 0; i < 3; i++)
|
| 464 |
|
|
sr.rdir[i] = np->prdir[i] +
|
| 465 |
|
|
d*(cosp*np->u[i] + sinp*np->v[i]);
|
| 466 |
greg |
2.55 |
if (DOT(sr.rdir, np->rp->ron) >= -FTINY)
|
| 467 |
greg |
2.47 |
continue;
|
| 468 |
|
|
normalize(sr.rdir); /* OK, normalize */
|
| 469 |
greg |
2.50 |
if (nstaken) /* multi-sampling */
|
| 470 |
greg |
2.47 |
rayclear(&sr);
|
| 471 |
|
|
rayvalue(&sr);
|
| 472 |
greg |
2.62 |
smultscolor(sr.rcol, sr.rcoef);
|
| 473 |
|
|
saddscolor(np->rp->rcol, sr.rcol);
|
| 474 |
greg |
2.50 |
++nstaken;
|
| 475 |
greg |
2.32 |
}
|
| 476 |
greg |
2.7 |
ndims--;
|
| 477 |
|
|
}
|
| 478 |
greg |
2.1 |
}
|
