| 1 |
#ifndef lint
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| 2 |
static const char RCSid[] = "$Id: m_bsdf.c,v 2.25 2014/01/22 16:39:57 greg Exp $";
|
| 3 |
#endif
|
| 4 |
/*
|
| 5 |
* Shading for materials with BSDFs taken from XML data files
|
| 6 |
*/
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| 7 |
|
| 8 |
#include "copyright.h"
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| 9 |
|
| 10 |
#include "ray.h"
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| 11 |
#include "ambient.h"
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| 12 |
#include "source.h"
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| 13 |
#include "func.h"
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| 14 |
#include "bsdf.h"
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| 15 |
#include "random.h"
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| 16 |
|
| 17 |
/*
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| 18 |
* Arguments to this material include optional diffuse colors.
|
| 19 |
* String arguments include the BSDF and function files.
|
| 20 |
* A non-zero thickness causes the strange but useful behavior
|
| 21 |
* of translating transmitted rays this distance beneath the surface
|
| 22 |
* (opposite the surface normal) to bypass any intervening geometry.
|
| 23 |
* Translation only affects scattered, non-source-directed samples.
|
| 24 |
* A non-zero thickness has the further side-effect that an unscattered
|
| 25 |
* (view) ray will pass right through our material if it has any
|
| 26 |
* non-diffuse transmission, making the BSDF surface invisible. This
|
| 27 |
* shows the proxied geometry instead. Thickness has the further
|
| 28 |
* effect of turning off reflection on the hidden side so that rays
|
| 29 |
* heading in the opposite direction pass unimpeded through the BSDF
|
| 30 |
* surface. A paired surface may be placed on the opposide side of
|
| 31 |
* the detail geometry, less than this thickness away, if a two-way
|
| 32 |
* proxy is desired. Note that the sign of the thickness is important.
|
| 33 |
* A positive thickness hides geometry behind the BSDF surface and uses
|
| 34 |
* front reflectance and transmission properties. A negative thickness
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| 35 |
* hides geometry in front of the surface when rays hit from behind,
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| 36 |
* and applies only the transmission and backside reflectance properties.
|
| 37 |
* Reflection is ignored on the hidden side, as those rays pass through.
|
| 38 |
* The "up" vector for the BSDF is given by three variables, defined
|
| 39 |
* (along with the thickness) by the named function file, or '.' if none.
|
| 40 |
* Together with the surface normal, this defines the local coordinate
|
| 41 |
* system for the BSDF.
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| 42 |
* We do not reorient the surface, so if the BSDF has no back-side
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| 43 |
* reflectance and none is given in the real arguments, a BSDF surface
|
| 44 |
* with zero thickness will appear black when viewed from behind
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| 45 |
* unless backface visibility is off.
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| 46 |
* The diffuse arguments are added to components in the BSDF file,
|
| 47 |
* not multiplied. However, patterns affect this material as a multiplier
|
| 48 |
* on everything except non-diffuse reflection.
|
| 49 |
*
|
| 50 |
* Arguments for MAT_BSDF are:
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| 51 |
* 6+ thick BSDFfile ux uy uz funcfile transform
|
| 52 |
* 0
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| 53 |
* 0|3|6|9 rdf gdf bdf
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| 54 |
* rdb gdb bdb
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| 55 |
* rdt gdt bdt
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| 56 |
*/
|
| 57 |
|
| 58 |
/*
|
| 59 |
* Note that our reverse ray-tracing process means that the positions
|
| 60 |
* of incoming and outgoing vectors may be reversed in our calls
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| 61 |
* to the BSDF library. This is fine, since the bidirectional nature
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| 62 |
* of the BSDF (that's what the 'B' stands for) means it all works out.
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| 63 |
*/
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| 64 |
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| 65 |
typedef struct {
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| 66 |
OBJREC *mp; /* material pointer */
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| 67 |
RAY *pr; /* intersected ray */
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| 68 |
FVECT pnorm; /* perturbed surface normal */
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| 69 |
FVECT vray; /* local outgoing (return) vector */
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| 70 |
double sr_vpsa[2]; /* sqrt of BSDF projected solid angle extrema */
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RREAL toloc[3][3]; /* world to local BSDF coords */
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RREAL fromloc[3][3]; /* local BSDF coords to world */
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double thick; /* surface thickness */
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| 74 |
SDData *sd; /* loaded BSDF data */
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COLOR runsamp; /* BSDF hemispherical reflection */
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COLOR rdiff; /* added diffuse reflection */
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| 77 |
COLOR tunsamp; /* BSDF hemispherical transmission */
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| 78 |
COLOR tdiff; /* added diffuse transmission */
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| 79 |
} BSDFDAT; /* BSDF material data */
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| 80 |
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| 81 |
#define cvt_sdcolor(cv, svp) ccy2rgb(&(svp)->spec, (svp)->cieY, cv)
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| 82 |
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| 83 |
/* Jitter ray sample according to projected solid angle and specjitter */
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static void
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bsdf_jitter(FVECT vres, BSDFDAT *ndp, double sr_psa)
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| 86 |
{
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| 87 |
VCOPY(vres, ndp->vray);
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| 88 |
if (specjitter < 1.)
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sr_psa *= specjitter;
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| 90 |
if (sr_psa <= FTINY)
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| 91 |
return;
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| 92 |
vres[0] += sr_psa*(.5 - frandom());
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| 93 |
vres[1] += sr_psa*(.5 - frandom());
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normalize(vres);
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}
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| 97 |
/* Evaluate BSDF for direct component, returning true if OK to proceed */
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| 98 |
static int
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| 99 |
direct_bsdf_OK(COLOR cval, FVECT ldir, double omega, BSDFDAT *ndp)
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{
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int nsamp, ok = 0;
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| 102 |
FVECT vsrc, vsmp, vjit;
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double tomega;
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| 104 |
double sf, tsr, sd[2];
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COLOR csmp;
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SDValue sv;
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| 107 |
SDError ec;
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int i;
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/* transform source direction */
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if (SDmapDir(vsrc, ndp->toloc, ldir) != SDEnone)
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return(0);
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/* assign number of samples */
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ec = SDsizeBSDF(&tomega, ndp->vray, vsrc, SDqueryMin, ndp->sd);
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if (ec)
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goto baderror;
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/* check indirect over-counting */
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if (ndp->thick != 0 && ndp->pr->crtype & (SPECULAR|AMBIENT)
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&& vsrc[2] > 0 ^ ndp->vray[2] > 0) {
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double dx = vsrc[0] + ndp->vray[0];
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double dy = vsrc[1] + ndp->vray[1];
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if (dx*dx + dy*dy <= omega+tomega)
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return(0);
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}
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sf = specjitter * ndp->pr->rweight;
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if (tomega <= .0)
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nsamp = 1;
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else if (25.*tomega <= omega)
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nsamp = 100.*sf + .5;
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else
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nsamp = 4.*sf*omega/tomega + .5;
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nsamp += !nsamp;
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setcolor(cval, .0, .0, .0); /* sample our source area */
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sf = sqrt(omega);
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tsr = sqrt(tomega);
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for (i = nsamp; i--; ) {
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VCOPY(vsmp, vsrc); /* jitter query directions */
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if (nsamp > 1) {
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multisamp(sd, 2, (i + frandom())/(double)nsamp);
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vsmp[0] += (sd[0] - .5)*sf;
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vsmp[1] += (sd[1] - .5)*sf;
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if (normalize(vsmp) == 0) {
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--nsamp;
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continue;
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}
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}
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bsdf_jitter(vjit, ndp, tsr);
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/* compute BSDF */
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ec = SDevalBSDF(&sv, vjit, vsmp, ndp->sd);
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if (ec)
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goto baderror;
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if (sv.cieY <= FTINY) /* worth using? */
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continue;
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cvt_sdcolor(csmp, &sv);
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addcolor(cval, csmp); /* average it in */
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++ok;
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}
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sf = 1./(double)nsamp;
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scalecolor(cval, sf);
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return(ok);
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baderror:
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objerror(ndp->mp, USER, transSDError(ec));
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return(0); /* gratis return */
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}
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/* Compute source contribution for BSDF (reflected & transmitted) */
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static void
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dir_bsdf(
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COLOR cval, /* returned coefficient */
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void *nnp, /* material data */
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FVECT ldir, /* light source direction */
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double omega /* light source size */
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)
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{
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BSDFDAT *np = (BSDFDAT *)nnp;
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double ldot;
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double dtmp;
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COLOR ctmp;
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setcolor(cval, .0, .0, .0);
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ldot = DOT(np->pnorm, ldir);
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if ((-FTINY <= ldot) & (ldot <= FTINY))
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return;
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if (ldot > 0 && bright(np->rdiff) > FTINY) {
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/*
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* Compute added diffuse reflected component.
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*/
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copycolor(ctmp, np->rdiff);
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dtmp = ldot * omega * (1./PI);
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scalecolor(ctmp, dtmp);
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addcolor(cval, ctmp);
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}
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if (ldot < 0 && bright(np->tdiff) > FTINY) {
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/*
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* Compute added diffuse transmission.
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*/
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copycolor(ctmp, np->tdiff);
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dtmp = -ldot * omega * (1.0/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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* Compute scattering coefficient using BSDF.
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*/
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if (!direct_bsdf_OK(ctmp, ldir, omega, np))
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return;
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if (ldot > 0) { /* pattern only diffuse reflection */
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COLOR ctmp1, ctmp2;
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dtmp = (np->pr->rod > 0) ? np->sd->rLambFront.cieY
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: np->sd->rLambBack.cieY;
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/* diffuse fraction */
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dtmp /= PI * bright(ctmp);
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copycolor(ctmp2, np->pr->pcol);
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scalecolor(ctmp2, dtmp);
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setcolor(ctmp1, 1.-dtmp, 1.-dtmp, 1.-dtmp);
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addcolor(ctmp1, ctmp2);
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multcolor(ctmp, ctmp1); /* apply derated pattern */
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dtmp = ldot * omega;
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} else { /* full pattern on transmission */
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multcolor(ctmp, np->pr->pcol);
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dtmp = -ldot * omega;
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}
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scalecolor(ctmp, dtmp);
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addcolor(cval, ctmp);
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}
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/* Compute source contribution for BSDF (reflected only) */
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static void
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dir_brdf(
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COLOR cval, /* returned coefficient */
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void *nnp, /* material data */
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FVECT ldir, /* light source direction */
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double omega /* light source size */
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)
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{
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BSDFDAT *np = (BSDFDAT *)nnp;
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double ldot;
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double dtmp;
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COLOR ctmp, ctmp1, ctmp2;
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| 242 |
setcolor(cval, .0, .0, .0);
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ldot = DOT(np->pnorm, ldir);
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| 246 |
if (ldot <= FTINY)
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return;
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| 248 |
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| 249 |
if (bright(np->rdiff) > FTINY) {
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| 250 |
/*
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| 251 |
* Compute added diffuse reflected component.
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| 252 |
*/
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copycolor(ctmp, np->rdiff);
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| 254 |
dtmp = ldot * omega * (1./PI);
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| 255 |
scalecolor(ctmp, dtmp);
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| 256 |
addcolor(cval, ctmp);
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| 257 |
}
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| 258 |
/*
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| 259 |
* Compute reflection coefficient using BSDF.
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| 260 |
*/
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| 261 |
if (!direct_bsdf_OK(ctmp, ldir, omega, np))
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| 262 |
return;
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| 263 |
/* pattern only diffuse reflection */
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| 264 |
dtmp = (np->pr->rod > 0) ? np->sd->rLambFront.cieY
|
| 265 |
: np->sd->rLambBack.cieY;
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| 266 |
dtmp /= PI * bright(ctmp); /* diffuse fraction */
|
| 267 |
copycolor(ctmp2, np->pr->pcol);
|
| 268 |
scalecolor(ctmp2, dtmp);
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| 269 |
setcolor(ctmp1, 1.-dtmp, 1.-dtmp, 1.-dtmp);
|
| 270 |
addcolor(ctmp1, ctmp2);
|
| 271 |
multcolor(ctmp, ctmp1); /* apply derated pattern */
|
| 272 |
dtmp = ldot * omega;
|
| 273 |
scalecolor(ctmp, dtmp);
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| 274 |
addcolor(cval, ctmp);
|
| 275 |
}
|
| 276 |
|
| 277 |
/* Compute source contribution for BSDF (transmitted only) */
|
| 278 |
static void
|
| 279 |
dir_btdf(
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| 280 |
COLOR cval, /* returned coefficient */
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| 281 |
void *nnp, /* material data */
|
| 282 |
FVECT ldir, /* light source direction */
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| 283 |
double omega /* light source size */
|
| 284 |
)
|
| 285 |
{
|
| 286 |
BSDFDAT *np = (BSDFDAT *)nnp;
|
| 287 |
double ldot;
|
| 288 |
double dtmp;
|
| 289 |
COLOR ctmp;
|
| 290 |
|
| 291 |
setcolor(cval, .0, .0, .0);
|
| 292 |
|
| 293 |
ldot = DOT(np->pnorm, ldir);
|
| 294 |
|
| 295 |
if (ldot >= -FTINY)
|
| 296 |
return;
|
| 297 |
|
| 298 |
if (bright(np->tdiff) > FTINY) {
|
| 299 |
/*
|
| 300 |
* Compute added diffuse transmission.
|
| 301 |
*/
|
| 302 |
copycolor(ctmp, np->tdiff);
|
| 303 |
dtmp = -ldot * omega * (1.0/PI);
|
| 304 |
scalecolor(ctmp, dtmp);
|
| 305 |
addcolor(cval, ctmp);
|
| 306 |
}
|
| 307 |
/*
|
| 308 |
* Compute scattering coefficient using BSDF.
|
| 309 |
*/
|
| 310 |
if (!direct_bsdf_OK(ctmp, ldir, omega, np))
|
| 311 |
return;
|
| 312 |
/* full pattern on transmission */
|
| 313 |
multcolor(ctmp, np->pr->pcol);
|
| 314 |
dtmp = -ldot * omega;
|
| 315 |
scalecolor(ctmp, dtmp);
|
| 316 |
addcolor(cval, ctmp);
|
| 317 |
}
|
| 318 |
|
| 319 |
/* Sample separate BSDF component */
|
| 320 |
static int
|
| 321 |
sample_sdcomp(BSDFDAT *ndp, SDComponent *dcp, int usepat)
|
| 322 |
{
|
| 323 |
int nstarget = 1;
|
| 324 |
int nsent;
|
| 325 |
SDError ec;
|
| 326 |
SDValue bsv;
|
| 327 |
double xrand;
|
| 328 |
FVECT vsmp;
|
| 329 |
RAY sr;
|
| 330 |
/* multiple samples? */
|
| 331 |
if (specjitter > 1.5) {
|
| 332 |
nstarget = specjitter*ndp->pr->rweight + .5;
|
| 333 |
nstarget += !nstarget;
|
| 334 |
}
|
| 335 |
/* run through our samples */
|
| 336 |
for (nsent = 0; nsent < nstarget; nsent++) {
|
| 337 |
if (nstarget == 1) { /* stratify random variable */
|
| 338 |
xrand = urand(ilhash(dimlist,ndims)+samplendx);
|
| 339 |
if (specjitter < 1.)
|
| 340 |
xrand = .5 + specjitter*(xrand-.5);
|
| 341 |
} else {
|
| 342 |
xrand = (nsent + frandom())/(double)nstarget;
|
| 343 |
}
|
| 344 |
SDerrorDetail[0] = '\0'; /* sample direction & coef. */
|
| 345 |
bsdf_jitter(vsmp, ndp, ndp->sr_vpsa[0]);
|
| 346 |
ec = SDsampComponent(&bsv, vsmp, xrand, dcp);
|
| 347 |
if (ec)
|
| 348 |
objerror(ndp->mp, USER, transSDError(ec));
|
| 349 |
if (bsv.cieY <= FTINY) /* zero component? */
|
| 350 |
break;
|
| 351 |
/* map vector to world */
|
| 352 |
if (SDmapDir(sr.rdir, ndp->fromloc, vsmp) != SDEnone)
|
| 353 |
break;
|
| 354 |
/* spawn a specular ray */
|
| 355 |
if (nstarget > 1)
|
| 356 |
bsv.cieY /= (double)nstarget;
|
| 357 |
cvt_sdcolor(sr.rcoef, &bsv); /* use sample color */
|
| 358 |
if (usepat) /* apply pattern? */
|
| 359 |
multcolor(sr.rcoef, ndp->pr->pcol);
|
| 360 |
if (rayorigin(&sr, SPECULAR, ndp->pr, sr.rcoef) < 0) {
|
| 361 |
if (maxdepth > 0)
|
| 362 |
break;
|
| 363 |
continue; /* Russian roulette victim */
|
| 364 |
}
|
| 365 |
/* need to offset origin? */
|
| 366 |
if (ndp->thick != 0 && ndp->pr->rod > 0 ^ vsmp[2] > 0)
|
| 367 |
VSUM(sr.rorg, sr.rorg, ndp->pr->ron, -ndp->thick);
|
| 368 |
rayvalue(&sr); /* send & evaluate sample */
|
| 369 |
multcolor(sr.rcol, sr.rcoef);
|
| 370 |
addcolor(ndp->pr->rcol, sr.rcol);
|
| 371 |
}
|
| 372 |
return(nsent);
|
| 373 |
}
|
| 374 |
|
| 375 |
/* Sample non-diffuse components of BSDF */
|
| 376 |
static int
|
| 377 |
sample_sdf(BSDFDAT *ndp, int sflags)
|
| 378 |
{
|
| 379 |
int n, ntotal = 0;
|
| 380 |
SDSpectralDF *dfp;
|
| 381 |
COLORV *unsc;
|
| 382 |
|
| 383 |
if (sflags == SDsampSpT) {
|
| 384 |
unsc = ndp->tunsamp;
|
| 385 |
if (ndp->pr->rod > 0)
|
| 386 |
dfp = (ndp->sd->tf != NULL) ? ndp->sd->tf : ndp->sd->tb;
|
| 387 |
else
|
| 388 |
dfp = (ndp->sd->tb != NULL) ? ndp->sd->tb : ndp->sd->tf;
|
| 389 |
cvt_sdcolor(unsc, &ndp->sd->tLamb);
|
| 390 |
} else /* sflags == SDsampSpR */ {
|
| 391 |
unsc = ndp->runsamp;
|
| 392 |
if (ndp->pr->rod > 0) {
|
| 393 |
dfp = ndp->sd->rf;
|
| 394 |
cvt_sdcolor(unsc, &ndp->sd->rLambFront);
|
| 395 |
} else {
|
| 396 |
dfp = ndp->sd->rb;
|
| 397 |
cvt_sdcolor(unsc, &ndp->sd->rLambBack);
|
| 398 |
}
|
| 399 |
}
|
| 400 |
multcolor(unsc, ndp->pr->pcol);
|
| 401 |
if (dfp == NULL) /* no specular component? */
|
| 402 |
return(0);
|
| 403 |
/* below sampling threshold? */
|
| 404 |
if (dfp->maxHemi <= specthresh+FTINY) {
|
| 405 |
if (dfp->maxHemi > FTINY) { /* XXX no color from BSDF */
|
| 406 |
FVECT vjit;
|
| 407 |
double d;
|
| 408 |
COLOR ctmp;
|
| 409 |
bsdf_jitter(vjit, ndp, ndp->sr_vpsa[1]);
|
| 410 |
d = SDdirectHemi(vjit, sflags, ndp->sd);
|
| 411 |
if (sflags == SDsampSpT) {
|
| 412 |
copycolor(ctmp, ndp->pr->pcol);
|
| 413 |
scalecolor(ctmp, d);
|
| 414 |
} else /* no pattern on reflection */
|
| 415 |
setcolor(ctmp, d, d, d);
|
| 416 |
addcolor(unsc, ctmp);
|
| 417 |
}
|
| 418 |
return(0);
|
| 419 |
}
|
| 420 |
/* else need to sample */
|
| 421 |
dimlist[ndims++] = (int)(size_t)ndp->mp;
|
| 422 |
ndims++;
|
| 423 |
for (n = dfp->ncomp; n--; ) { /* loop over components */
|
| 424 |
dimlist[ndims-1] = n + 9438;
|
| 425 |
ntotal += sample_sdcomp(ndp, &dfp->comp[n], sflags==SDsampSpT);
|
| 426 |
}
|
| 427 |
ndims -= 2;
|
| 428 |
return(ntotal);
|
| 429 |
}
|
| 430 |
|
| 431 |
/* Color a ray that hit a BSDF material */
|
| 432 |
int
|
| 433 |
m_bsdf(OBJREC *m, RAY *r)
|
| 434 |
{
|
| 435 |
int hitfront;
|
| 436 |
COLOR ctmp;
|
| 437 |
SDError ec;
|
| 438 |
FVECT upvec, vtmp;
|
| 439 |
MFUNC *mf;
|
| 440 |
BSDFDAT nd;
|
| 441 |
/* check arguments */
|
| 442 |
if ((m->oargs.nsargs < 6) | (m->oargs.nfargs > 9) |
|
| 443 |
(m->oargs.nfargs % 3))
|
| 444 |
objerror(m, USER, "bad # arguments");
|
| 445 |
/* record surface struck */
|
| 446 |
hitfront = (r->rod > 0);
|
| 447 |
/* load cal file */
|
| 448 |
mf = getfunc(m, 5, 0x1d, 1);
|
| 449 |
setfunc(m, r);
|
| 450 |
/* get thickness */
|
| 451 |
nd.thick = evalue(mf->ep[0]);
|
| 452 |
if ((-FTINY <= nd.thick) & (nd.thick <= FTINY))
|
| 453 |
nd.thick = .0;
|
| 454 |
/* check shadow */
|
| 455 |
if (r->crtype & SHADOW) {
|
| 456 |
if (nd.thick != 0)
|
| 457 |
raytrans(r); /* pass-through */
|
| 458 |
return(1); /* or shadow */
|
| 459 |
}
|
| 460 |
/* check backface visibility */
|
| 461 |
if (!hitfront & !backvis) {
|
| 462 |
raytrans(r);
|
| 463 |
return(1);
|
| 464 |
}
|
| 465 |
/* check other rays to pass */
|
| 466 |
if (nd.thick != 0 && (!(r->crtype & (SPECULAR|AMBIENT)) ||
|
| 467 |
nd.thick > 0 ^ hitfront)) {
|
| 468 |
raytrans(r); /* hide our proxy */
|
| 469 |
return(1);
|
| 470 |
}
|
| 471 |
/* get BSDF data */
|
| 472 |
nd.sd = loadBSDF(m->oargs.sarg[1]);
|
| 473 |
/* diffuse reflectance */
|
| 474 |
if (hitfront) {
|
| 475 |
if (m->oargs.nfargs < 3)
|
| 476 |
setcolor(nd.rdiff, .0, .0, .0);
|
| 477 |
else
|
| 478 |
setcolor(nd.rdiff, m->oargs.farg[0],
|
| 479 |
m->oargs.farg[1],
|
| 480 |
m->oargs.farg[2]);
|
| 481 |
} else {
|
| 482 |
if (m->oargs.nfargs < 6)
|
| 483 |
setcolor(nd.rdiff, .0, .0, .0);
|
| 484 |
else
|
| 485 |
setcolor(nd.rdiff, m->oargs.farg[3],
|
| 486 |
m->oargs.farg[4],
|
| 487 |
m->oargs.farg[5]);
|
| 488 |
}
|
| 489 |
/* diffuse transmittance */
|
| 490 |
if (m->oargs.nfargs < 9)
|
| 491 |
setcolor(nd.tdiff, .0, .0, .0);
|
| 492 |
else
|
| 493 |
setcolor(nd.tdiff, m->oargs.farg[6],
|
| 494 |
m->oargs.farg[7],
|
| 495 |
m->oargs.farg[8]);
|
| 496 |
nd.mp = m;
|
| 497 |
nd.pr = r;
|
| 498 |
/* get modifiers */
|
| 499 |
raytexture(r, m->omod);
|
| 500 |
/* modify diffuse values */
|
| 501 |
multcolor(nd.rdiff, r->pcol);
|
| 502 |
multcolor(nd.tdiff, r->pcol);
|
| 503 |
/* get up vector */
|
| 504 |
upvec[0] = evalue(mf->ep[1]);
|
| 505 |
upvec[1] = evalue(mf->ep[2]);
|
| 506 |
upvec[2] = evalue(mf->ep[3]);
|
| 507 |
/* return to world coords */
|
| 508 |
if (mf->fxp != &unitxf) {
|
| 509 |
multv3(upvec, upvec, mf->fxp->xfm);
|
| 510 |
nd.thick *= mf->fxp->sca;
|
| 511 |
}
|
| 512 |
if (r->rox != NULL) {
|
| 513 |
multv3(upvec, upvec, r->rox->f.xfm);
|
| 514 |
nd.thick *= r->rox->f.sca;
|
| 515 |
}
|
| 516 |
raynormal(nd.pnorm, r);
|
| 517 |
/* compute local BSDF xform */
|
| 518 |
ec = SDcompXform(nd.toloc, nd.pnorm, upvec);
|
| 519 |
if (!ec) {
|
| 520 |
nd.vray[0] = -r->rdir[0];
|
| 521 |
nd.vray[1] = -r->rdir[1];
|
| 522 |
nd.vray[2] = -r->rdir[2];
|
| 523 |
ec = SDmapDir(nd.vray, nd.toloc, nd.vray);
|
| 524 |
}
|
| 525 |
if (!ec)
|
| 526 |
ec = SDinvXform(nd.fromloc, nd.toloc);
|
| 527 |
if (ec) {
|
| 528 |
objerror(m, WARNING, "Illegal orientation vector");
|
| 529 |
return(1);
|
| 530 |
}
|
| 531 |
/* determine BSDF resolution */
|
| 532 |
ec = SDsizeBSDF(nd.sr_vpsa, nd.vray, NULL, SDqueryMin+SDqueryMax, nd.sd);
|
| 533 |
if (ec)
|
| 534 |
objerror(m, USER, transSDError(ec));
|
| 535 |
|
| 536 |
nd.sr_vpsa[0] = sqrt(nd.sr_vpsa[0]);
|
| 537 |
nd.sr_vpsa[1] = sqrt(nd.sr_vpsa[1]);
|
| 538 |
if (!hitfront) { /* perturb normal towards hit */
|
| 539 |
nd.pnorm[0] = -nd.pnorm[0];
|
| 540 |
nd.pnorm[1] = -nd.pnorm[1];
|
| 541 |
nd.pnorm[2] = -nd.pnorm[2];
|
| 542 |
}
|
| 543 |
/* sample reflection */
|
| 544 |
sample_sdf(&nd, SDsampSpR);
|
| 545 |
/* sample transmission */
|
| 546 |
sample_sdf(&nd, SDsampSpT);
|
| 547 |
/* compute indirect diffuse */
|
| 548 |
copycolor(ctmp, nd.rdiff);
|
| 549 |
addcolor(ctmp, nd.runsamp);
|
| 550 |
if (bright(ctmp) > FTINY) { /* ambient from reflection */
|
| 551 |
if (!hitfront)
|
| 552 |
flipsurface(r);
|
| 553 |
multambient(ctmp, r, nd.pnorm);
|
| 554 |
addcolor(r->rcol, ctmp);
|
| 555 |
if (!hitfront)
|
| 556 |
flipsurface(r);
|
| 557 |
}
|
| 558 |
copycolor(ctmp, nd.tdiff);
|
| 559 |
addcolor(ctmp, nd.tunsamp);
|
| 560 |
if (bright(ctmp) > FTINY) { /* ambient from other side */
|
| 561 |
FVECT bnorm;
|
| 562 |
if (hitfront)
|
| 563 |
flipsurface(r);
|
| 564 |
bnorm[0] = -nd.pnorm[0];
|
| 565 |
bnorm[1] = -nd.pnorm[1];
|
| 566 |
bnorm[2] = -nd.pnorm[2];
|
| 567 |
if (nd.thick != 0) { /* proxy with offset? */
|
| 568 |
VCOPY(vtmp, r->rop);
|
| 569 |
VSUM(r->rop, vtmp, r->ron, nd.thick);
|
| 570 |
multambient(ctmp, r, bnorm);
|
| 571 |
VCOPY(r->rop, vtmp);
|
| 572 |
} else
|
| 573 |
multambient(ctmp, r, bnorm);
|
| 574 |
addcolor(r->rcol, ctmp);
|
| 575 |
if (hitfront)
|
| 576 |
flipsurface(r);
|
| 577 |
}
|
| 578 |
/* add direct component */
|
| 579 |
if ((bright(nd.tdiff) <= FTINY) & (nd.sd->tf == NULL) &
|
| 580 |
(nd.sd->tb == NULL)) {
|
| 581 |
direct(r, dir_brdf, &nd); /* reflection only */
|
| 582 |
} else if (nd.thick == 0) {
|
| 583 |
direct(r, dir_bsdf, &nd); /* thin surface scattering */
|
| 584 |
} else {
|
| 585 |
direct(r, dir_brdf, &nd); /* reflection first */
|
| 586 |
VCOPY(vtmp, r->rop); /* offset for transmitted */
|
| 587 |
VSUM(r->rop, vtmp, r->ron, -nd.thick);
|
| 588 |
direct(r, dir_btdf, &nd); /* separate transmission */
|
| 589 |
VCOPY(r->rop, vtmp);
|
| 590 |
}
|
| 591 |
/* clean up */
|
| 592 |
SDfreeCache(nd.sd);
|
| 593 |
return(1);
|
| 594 |
}
|
