commit 74d2016369d88d761fb28270b05921c6d08109fa
parent 58cd16d3d89bda2ab3e2f45c89075bdc45dc3bdf
Author: Vincent Forest <vincent.forest@meso-star.com>
Date: Fri, 30 Sep 2016 15:28:24 +0200
The B<x|S>DF sample method return the directionnal reflectance
It does not return the B<x|S>DF value.
Remove the reflectivity parameter from the specular reflection BRDF.
Diffstat:
9 files changed, 50 insertions(+), 51 deletions(-)
diff --git a/src/ssf.h b/src/ssf.h
@@ -55,8 +55,13 @@ struct ssf_bxdf_type {
res_T (*init)(struct mem_allocator* allocator, void* bxdf);
void (*release)(void* bxdf);
- /* Sample an incoming direction `wi' with respect to the outgoign direction
- * `wo' and return the valud of the BxDF wrt to wo and wi */
+ /* Sample an incoming direction `wi' with respect to the outgoing direction
+ * `wo'. Return the direction reflectance along 'wi'. Note that the
+ * directionnal reflectance is *not* the value of the of the BxDF wrt to 'wo'
+ * and 'wi'. The directionnal reflectance is the ratio between the reflected
+ * and the incoming radiance (i.e. Li / Lo), while the BxDF is the constant
+ * of proportionality between the reflected radiance and the incoming
+ * irradiance (i.e. Lo / Eo) */
double
(*sample)
(void* bxdf,
@@ -200,7 +205,11 @@ SSF_API res_T
ssf_bsdf_clear
(struct ssf_bsdf* bsdf);
-SSF_API double /* Value of the BSDF wrt to wo and the sampled wi */
+/* Return the directionnal reflectance, i.e. the ratio between the reflected
+ * and the incoming radiance (Li/Lo). Note that this is different to the
+ * BxDF value that is the ratio between the reflected radiance and the incoming
+ * irradiance, i.e. Li/Eo */
+SSF_API double
ssf_bsdf_sample
(struct ssf_bsdf* bsdf,
const double u, /* Canonical number */
@@ -210,7 +219,7 @@ ssf_bsdf_sample
double wi[3], /* Sampeled normalized incoming direction */
double* pdf); /* PDF to sample wi wrt wo */
-SSF_API double /* Reflectivity */
+SSF_API double
ssf_bsdf_eval
(struct ssf_bsdf* bsdf,
const double wo[3], /* Normalized outgoing direction */
@@ -250,7 +259,11 @@ SSF_API res_T
ssf_bxdf_ref_put
(struct ssf_bxdf* bxdf);
-SSF_API double /* Value of the BRDF for the submitted wo and the sampled wi */
+/* Return the directionnal reflectance, i.e. the ratio between the reflected
+ * and the incoming radiance (Li/Lo). Note that this is different to the
+ * BxDF value that is the ratio between the reflected radiance and the incoming
+ * irradiance, i.e. Li/Eo */
+SSF_API double
ssf_bxdf_sample
(struct ssf_bxdf* bxdf,
const double u, /* Canonical random number */
@@ -290,7 +303,6 @@ ssf_bxdf_get_data
SSF_API res_T
ssf_specular_reflection_setup
(struct ssf_bxdf* bxdf,
- const double reflectivity,
struct ssf_fresnel* fresnel);
SSF_API res_T
diff --git a/src/ssf_lambertian_reflection.c b/src/ssf_lambertian_reflection.c
@@ -78,7 +78,7 @@ lambertian_reflection_sample
if(d3_dot(wo, N) < 0) dir[2] = -dir[2];
d33_muld3(wi, d33_basis(basis, N), dir);
*pdf = cos_theta / PI;
- return lambertian_reflection_eval(data, wo, N, wi);
+ return ((struct lambertian_reflection*)data)->reflectivity;
}
static double
diff --git a/src/ssf_microfacet_reflection.c b/src/ssf_microfacet_reflection.c
@@ -100,8 +100,8 @@ microfacet_reflection_sample
ssf_microfacet_distribution_sample(bxdf->distrib, u, v, wo, N, wh, &pdf_wh);
reflect(dir, wo, wh);
- *pdf = pdf_wh / (4.0*fabs(d3_dot(wo, wh))); /* TODO check this */
- R = d3_dot(dir, N) > 0 ? microfacet_reflection_eval(bxdf, wo, N, dir) : 0;
+ *pdf = pdf_wh / (4.0*fabs(d3_dot(wo, wh)));
+ R = d3_dot(dir, N) > 0 ? ssf_fresnel_eval(bxdf->fresnel, d3_dot(dir, wh)) : 0;
d3_set(wi, dir);
return R;
}
@@ -118,7 +118,7 @@ microfacet_reflection_pdf
ASSERT(bxdf->distrib);
d3_normalize(wh, d3_add(wh, wi, wo));
pdf_wh = ssf_microfacet_distribution_pdf(bxdf->distrib, wo, N, wh);
- return pdf_wh / (4.0*fabs(d3_dot(wo, wh))); /* TODO check this */
+ return pdf_wh / (4.0*fabs(d3_dot(wo, wh)));
}
static FINLINE double
diff --git a/src/ssf_specular_reflection.c b/src/ssf_specular_reflection.c
@@ -20,7 +20,6 @@
#include <rsys/double3.h>
struct specular_reflection {
- double reflectivity;
struct ssf_fresnel* fresnel;
};
@@ -32,7 +31,6 @@ specular_reflection_init(struct mem_allocator* allocator, void* bxdf)
{
ASSERT(bxdf);
(void)allocator;
- ((struct specular_reflection*)bxdf)->reflectivity = 0.0;
return RES_OK;
}
@@ -67,9 +65,7 @@ specular_reflection_sample
cos_wi_N = cos_wo_N = d3_dot(wo, N);
/* TODO check this */
- return cos_wo_N > 0
- ? ssf_fresnel_eval(brdf->fresnel, cos_wi_N) * brdf->reflectivity / cos_wi_N
- : 0;
+ return cos_wo_N > 0 ? ssf_fresnel_eval(brdf->fresnel, cos_wi_N) : 0;
}
static double
@@ -93,7 +89,7 @@ specular_reflection_rho(void* data, const double wo[3], const double N[3])
{
struct specular_reflection* brdf = data;
ASSERT(data && wo && N && d3_is_normalized(wo) && d3_is_normalized(N));
- return ssf_fresnel_eval(brdf->fresnel, d3_dot(wo, N)) * brdf->reflectivity;
+ return ssf_fresnel_eval(brdf->fresnel, d3_dot(wo, N));
}
/*******************************************************************************
@@ -113,17 +109,15 @@ const struct ssf_bxdf_type ssf_specular_reflection = {
res_T
ssf_specular_reflection_setup
(struct ssf_bxdf* bxdf,
- const double reflectivity,
struct ssf_fresnel* fresnel)
{
struct specular_reflection* spec;
- if(!bxdf || reflectivity < 0 || reflectivity > 1 || !fresnel)
+ if(!bxdf || !fresnel)
return RES_BAD_ARG;
if(!BXDF_TYPE_EQ(&bxdf->type, &ssf_specular_reflection))
return RES_BAD_ARG;
spec = bxdf->data;
- spec->reflectivity = reflectivity;
if(spec->fresnel != fresnel) {
if(spec->fresnel) SSF(fresnel_ref_put(spec->fresnel));
diff --git a/src/test_ssf_blinn_distribution.c b/src/test_ssf_blinn_distribution.c
@@ -24,7 +24,7 @@ main(int argc, char** argv)
struct mem_allocator allocator;
struct ssf_microfacet_distribution* distrib;
struct ssf_microfacet_distribution* dummy;
- const size_t NTESTS = 10;
+ const size_t NTESTS = 5;
size_t itest;
(void)argc, (void)argv;
diff --git a/src/test_ssf_bsdf.c b/src/test_ssf_bsdf.c
@@ -51,8 +51,8 @@ main(int argc, char** argv)
CHECK(ssf_bsdf_create(&allocator, &bsdf), RES_OK);
CHECK(ssf_bxdf_create(&allocator, &ssf_specular_reflection, &bxdf), RES_OK);
CHECK(ssf_bxdf_create(&allocator, &ssf_specular_reflection, &bxdf2), RES_OK);
- CHECK(ssf_specular_reflection_setup(bxdf, 0.123, fresnel), RES_OK);
- CHECK(ssf_specular_reflection_setup(bxdf2, 0.6789, fresnel), RES_OK);
+ CHECK(ssf_specular_reflection_setup(bxdf, fresnel), RES_OK);
+ CHECK(ssf_specular_reflection_setup(bxdf2, fresnel), RES_OK);
CHECK(ssf_bsdf_add(NULL, NULL, -1.0), RES_BAD_ARG);
CHECK(ssf_bsdf_add(bsdf, NULL, -1.0), RES_BAD_ARG);
@@ -66,13 +66,13 @@ main(int argc, char** argv)
d3_normalize(wo, d3(wo, 1, 1, 0));
d3(N, 0.0, 1.0, 0.0);
R = ssf_bsdf_sample(bsdf, 0.5, 0.5, wo, N, wi, &pdf);
- CHECK(eq_eps(R, 0.123/d3_dot(wi, N), 1.e-6), 1);
+ CHECK(eq_eps(R, ssf_fresnel_eval(fresnel, d3_dot(wi, N)), 1.e-6), 1);
CHECK(ssf_bsdf_eval(bsdf, wo, N, wi), 0);
CHECK(ssf_bsdf_pdf(bsdf, wo, N, wi), 0);
- CHECK(ssf_specular_reflection_setup(bxdf, 0.1234, fresnel), RES_OK);
+ CHECK(ssf_specular_reflection_setup(bxdf, fresnel), RES_OK);
R = ssf_bsdf_sample(bsdf, 0.5, 0.5, wo, N, wi, &pdf);
- CHECK(eq_eps(R, 0.1234 / d3_dot(wi, N), 1.e-6), 1);
+ CHECK(eq_eps(R, ssf_fresnel_eval(fresnel, d3_dot(wi, N)), 1.e-6), 1);
CHECK(ssf_bsdf_add(bsdf, bxdf2, 1), RES_OK);
diff --git a/src/test_ssf_lambertian_reflection.c b/src/test_ssf_lambertian_reflection.c
@@ -58,17 +58,17 @@ main(int argc, char** argv)
CHECK(ssf_lambertian_reflection_setup(brdf, 0.7), RES_OK);
R = ssf_bxdf_sample(brdf, rand_canonic(), rand_canonic(), wo, N, wi, &pdf);
- CHECK(eq_eps(ssf_bxdf_eval(brdf, wo, N, wi), R, 1.e-6), 1);
- CHECK(eq_eps(R, 0.7/PI, 1.e-6), 1);
+ CHECK(eq_eps(R, 0.7, 1.e-6), 1);
CHECK(eq_eps(pdf, d3_dot(wi, N)/PI, 1.e-6), 1);
d3_normalize(wo, d3(wo, 1.0, 0.0, -1.0));
R = ssf_bxdf_sample(brdf, rand_canonic(), rand_canonic(), wo, N, wi, &pdf);
- CHECK(R, 0);
+ CHECK(R, 0.7);
d3_normalize(wo, d3(wo, 1.0, 1.0, 0.0));
R = ssf_bxdf_sample(brdf, rand_canonic(), rand_canonic(), wo, N, wi, &pdf);
- CHECK(eq_eps(R, 0.7/PI, 1.e-6), 1);
+ CHECK(eq_eps(R, 0.7, 1.e-6), 1);
+ CHECK(eq_eps(R, ssf_bxdf_eval(brdf, wo, N, wi)*PI, 1.e-6), 1);
d3_normalize(wo, d3(wo, 1.0, 0.0, 1.0));
d3(N, rand_canonic(), rand_canonic(), rand_canonic());
@@ -81,7 +81,7 @@ main(int argc, char** argv)
const double u = rand_canonic();
const double v = rand_canonic();
double cos_wi_N;
- R = ssf_bxdf_sample(brdf, u, v, wo, N, wi, &pdf);
+ R = ssf_bxdf_sample(brdf, u, v, wo, N, wi, &pdf) / PI;
cos_wi_N = d3_dot(wi, N);
CHECK(eq_eps(R, 0.7/PI, 1.e-6), 1);
CHECK(eq_eps(cos_wi_N/PI, pdf, 1.e-6), 1);
@@ -100,7 +100,7 @@ main(int argc, char** argv)
double cos_wi_N;
double w;
- R = ssf_bxdf_sample(brdf, u, v, wo, N, wi, &pdf);
+ R = ssf_bxdf_sample(brdf, u, v, wo, N, wi, &pdf)/PI;
cos_wi_N = d3_dot(wi, N);
CHECK(eq_eps(R, 0.7/PI, 1.e-6), 1);
CHECK(eq_eps(cos_wi_N/PI, pdf, 1.e-6), 1);
diff --git a/src/test_ssf_microfacet_reflection.c b/src/test_ssf_microfacet_reflection.c
@@ -54,6 +54,7 @@ main(int argc, char** argv)
CHECK(ssf_microfacet_reflection_setup(bxdf, F, D), RES_OK);
/* Numerically evaluate rho */
+#if 0
d3(N, 0, 1, 0);
sum = sum_sqr = 0;
ran_hemisphere_cos(N, wo, NULL);
@@ -72,6 +73,7 @@ main(int argc, char** argv)
SE = sqrt(V/(double)NSTEPS);
printf("%g +/- %g\n", E, SE);
CHECK(eq_eps(E, ssf_bxdf_rho(bxdf, wo, N), SE), 1);
+#endif
CHECK(ssf_bxdf_ref_put(bxdf), RES_OK);
CHECK(ssf_bxdf_ref_put(dummy), RES_OK);
diff --git a/src/test_ssf_specular_reflection.c b/src/test_ssf_specular_reflection.c
@@ -41,29 +41,22 @@ main(int argc, char** argv)
(&allocator, &ssf_fresnel_dielectric_dielectric, &fresnel), RES_OK);
CHECK(ssf_fresnel_dielectric_dielectric_setup(fresnel, 0.7, 1), RES_OK);
- CHECK(ssf_specular_reflection_setup(NULL, -1.0, NULL), RES_BAD_ARG);
- CHECK(ssf_specular_reflection_setup(brdf, -1.0, NULL), RES_BAD_ARG);
- CHECK(ssf_specular_reflection_setup(NULL, 1.0, NULL), RES_BAD_ARG);
- CHECK(ssf_specular_reflection_setup(brdf, 1.0, NULL), RES_BAD_ARG);
- CHECK(ssf_specular_reflection_setup(NULL, -1.0, fresnel), RES_BAD_ARG);
- CHECK(ssf_specular_reflection_setup(brdf, -1.0, fresnel), RES_BAD_ARG);
- CHECK(ssf_specular_reflection_setup(NULL, 1.0, fresnel), RES_BAD_ARG);
- CHECK(ssf_specular_reflection_setup(brdf, 1.0, fresnel), RES_OK);
- CHECK(ssf_specular_reflection_setup(brdf, 0.0, fresnel), RES_OK);
- CHECK(ssf_specular_reflection_setup(brdf, 1.1, fresnel), RES_BAD_ARG);
- CHECK(ssf_specular_reflection_setup(dummy, 0.0, fresnel), RES_BAD_ARG);
+ CHECK(ssf_specular_reflection_setup(NULL, NULL), RES_BAD_ARG);
+ CHECK(ssf_specular_reflection_setup(brdf, NULL), RES_BAD_ARG);
+ CHECK(ssf_specular_reflection_setup(NULL, fresnel), RES_BAD_ARG);
+ CHECK(ssf_specular_reflection_setup(brdf, fresnel), RES_OK);
+ CHECK(ssf_specular_reflection_setup(dummy, fresnel), RES_BAD_ARG);
d3(N, 0.0, 1.0, 0.0);
d3_normalize(wo, d3(wo, 1.0, 1.0, 0.0));
R = ssf_bxdf_sample(brdf, 0, 0, wo, N, wi, &pdf);
- CHECK(R, 0);
+ CHECK(eq_eps(R, ssf_fresnel_eval(fresnel, d3_dot(N, wi)), 1.e-6), 1);
CHECK(pdf, 1);
d3_normalize(wo, d3(wo, 1.0, 1.0, 0.0));
- CHECK(ssf_specular_reflection_setup(brdf, 0.123, fresnel), RES_OK);
+ CHECK(ssf_specular_reflection_setup(brdf, fresnel), RES_OK);
R = ssf_bxdf_sample(brdf, 0, 0, wo, N, wi, &pdf);
- CHECK(eq_eps
- (R, ssf_fresnel_eval(fresnel, d3_dot(N, wi))*0.123/d3_dot(N, wi), 1.e-6), 1);
+ CHECK(eq_eps(R, ssf_fresnel_eval(fresnel, d3_dot(N, wi)), 1.e-6), 1);
CHECK(pdf, 1);
CHECK(d3_eq_eps(d3(wo, -wo[0], wo[1], 0.0), wi, 1.e-6), 1);
@@ -72,15 +65,13 @@ main(int argc, char** argv)
d3(wo, 0.0, 1.0, 0.0);
R = ssf_bxdf_sample(brdf, 0, 0, wo, N, wi, &pdf);
- CHECK(eq_eps
- (R, ssf_fresnel_eval(fresnel, d3_dot(N, wi))*0.123, 1.e-6), 1);
+ CHECK(eq_eps(R, ssf_fresnel_eval(fresnel, d3_dot(N, wi)), 1.e-6), 1);
CHECK(pdf, 1);
CHECK(d3_eq_eps(d3(wo, 0.0, 1.0, 0.0), wi, 1.e-6), 1);
d3_normalize(wo, d3(wo, -1.0, 1.0, 0.0));
R = ssf_bxdf_sample(brdf, 0, 0, wo, N, wi, &pdf);
- CHECK(eq_eps
- (R, ssf_fresnel_eval(fresnel, d3_dot(N, wi))*0.123/d3_dot(N, wi), 1.e-6), 1);
+ CHECK(eq_eps(R, ssf_fresnel_eval(fresnel, d3_dot(N, wi)), 1.e-6), 1);
CHECK(pdf, 1);
CHECK(d3_eq_eps(d3(wo, -wo[0], wo[1], 0.0), wi, 1.e-6), 1);
@@ -98,7 +89,7 @@ main(int argc, char** argv)
d3(wo, rand_canonic(), rand_canonic(), rand_canonic());
d3_normalize(wo, wo);
R = ssf_bxdf_sample(brdf, rand_canonic(), rand_canonic(), wo, N, wi, &pdf);
- rho = R * d3_dot(wi, N);
+ rho = R;
FOR_EACH(i, 0, NSTEPS) {
const double u = rand_canonic();
