commit baf003b7f49e869c6508f281f920ba2f74d32a16
parent 7dcb470663b0052fc03212a8a146d08a83af446b
Author: Vincent Forest <vincent.forest@meso-star.com>
Date: Wed, 19 Apr 2017 11:30:42 +0200
Handle perturbed normals in the solver
Diffstat:
| M | src/ssol_solver.c | | | 81 | ++++++++++++++++++++++++++++++++++++++++++++++++------------------------------- |
1 file changed, 49 insertions(+), 32 deletions(-)
diff --git a/src/ssol_solver.c b/src/ssol_solver.c
@@ -191,6 +191,12 @@ struct point {
}
static const struct point POINT_NULL = POINT_NULL__;
+static FINLINE struct ssol_material*
+point_get_material(const struct point* pt)
+{
+ return pt->side == SSOL_FRONT ? pt->sshape->mtl_front : pt->sshape->mtl_back;
+}
+
static res_T
point_init
(struct point* pt,
@@ -204,9 +210,12 @@ point_init
struct ssp_rng* rng,
int* is_lit)
{
+ struct ssol_surface_fragment frag;
struct s3d_attrib attr;
struct s3d_hit hit;
struct ray_data ray_data = RAY_DATA_NULL;
+ struct ssol_material* mtl;
+ double N[3], Np[3];
float dir[3], pos[3], range[2] = { 0, FLT_MAX };
size_t id;
res_T res = RES_OK;
@@ -240,39 +249,50 @@ point_init
/* Sample a sun direction */
ranst_sun_dir_get(ran_sun_dir, rng, pt->dir);
- /* Initialise the Monte Carlo weight */
if(pt->sshape->shape->type != SHAPE_PUNCHED) {
- double surface_sun_cos = fabs(d3_dot(pt->N, pt->dir));
- pt->weight = scn->sun->dni * sampled_area_proxy * surface_sun_cos;
- pt->cos_factor = surface_sun_cos;
+ d3_set(N, pt->N);
} else {
- double cos_ratio, surface_proxy_cos, surface_sun_cos, tmp_n[3];
/* For punched surface, retrieve the sampled position and normal onto the
* quadric surface */
punched_shape_project_point
- (pt->sshape->shape, pt->inst->transform, pt->pos, pt->pos, tmp_n);
- surface_proxy_cos = fabs(d3_dot(pt->N, tmp_n));
- surface_sun_cos = fabs(d3_dot(tmp_n, pt->dir));
+ (pt->sshape->shape, pt->inst->transform, pt->pos, pt->pos, N);
+ }
+
+ /* Define the primitive side on which the point lies */
+ if(d3_dot(N, pt->dir) < 0) {
+ pt->side = SSOL_FRONT;
+ } else {
+ pt->side = SSOL_BACK;
+ d3_minus(N, N); /* Force the normal to look forward dir */
+ }
+
+ /* Perturb the normal */
+ surface_fragment_setup(&frag, pt->pos, pt->dir, N, &pt->prim, pt->uv);
+ mtl = point_get_material(pt);
+ material_shade_normal(mtl, &frag, pt->wl, Np);
+
+ /* Initialise the Monte Carlo weight */
+ if(pt->sshape->shape->type != SHAPE_PUNCHED) {
+ double surface_sun_cos = fabs(d3_dot(Np, pt->dir));
+ pt->weight = scn->sun->dni * sampled_area_proxy * surface_sun_cos;
+ pt->cos_factor = surface_sun_cos;
+ } else {
+ double cos_ratio, surface_proxy_cos, surface_sun_cos;
+ surface_proxy_cos = fabs(d3_dot(pt->N, Np));
+ surface_sun_cos = fabs(d3_dot(Np, pt->dir));
cos_ratio = surface_sun_cos / surface_proxy_cos;
- d3_set(pt->N, tmp_n);
pt->weight = scn->sun->dni * sampled_area_proxy * cos_ratio;
pt->cos_factor = surface_sun_cos;
}
+ d3_set(pt->N, N);
pt->absorptivity_loss = pt->reflectivity_loss = 0;
+ ASSERT(d3_dot(pt->N, pt->dir) <= 0);
/* Store sampled entity related weights */
res = get_mc_sampled(sampled, pt->inst, &pt->mc_samp);
if(res != RES_OK) goto error;
pt->mc_samp->nb_samples++;
- /* Define the primitive side on which the point lies */
- if(d3_dot(pt->N, pt->dir) < 0) {
- pt->side = SSOL_FRONT;
- } else {
- pt->side = SSOL_BACK;
- d3_minus(pt->N, pt->N); /* Force the normal to look forward dir */
- }
-
/* Initialise the ray data to avoid self intersection */
ray_data.scn = scn;
ray_data.prim_from = pt->prim;
@@ -345,12 +365,6 @@ point_update_from_hit
}
}
-static FINLINE struct ssol_material*
-point_get_material(const struct point* pt)
-{
- return pt->side == SSOL_FRONT ? pt->sshape->mtl_front : pt->sshape->mtl_back;
-}
-
static FINLINE res_T
point_shade
(struct point* pt,
@@ -362,7 +376,7 @@ point_shade
struct ssol_material* mtl;
struct ssol_surface_fragment frag;
double r = 1;
- double wi[3], pdf;
+ double wi[3], N[3], pdf;
int type;
res_T res;
ASSERT(pt && bsdf && medium && rng && dir);
@@ -386,19 +400,22 @@ point_shade
res = material_setup_bsdf(mtl, &frag, pt->wl, medium, 0, bsdf);
if(res != RES_OK) return res;
+ /* Perturbe the normal */
+ material_shade_normal(mtl, &frag, pt->wl, N);
+
/* By convention, Star-SF assumes that incoming and reflected
* directions point outward the surface => negate incoming dir */
d3_minus(wi, pt->dir);
- if(d3_dot(wi, frag.Ns) <= 0) {
+ if(d3_dot(wi, N) <= 0) {
r = 0;
} else {
double cos_dir_Ng;
- r = ssf_bsdf_sample(bsdf, rng, wi, frag.Ns, dir, &type, &pdf);
+ r = ssf_bsdf_sample(bsdf, rng, wi, N, dir, &type, &pdf);
ASSERT(0 <= r && r <= 1);
- /* Due to the shading normal, the sampled direction may point in the wrong
- * direction wrt the sampled BSDF component. */
+ /* Due to the perturbed normal, the sampled direction may point in the
+ * wrong direction wrt the sampled BSDF component. */
cos_dir_Ng = d3_dot(frag.Ng, dir);
if((cos_dir_Ng > 0 && (type & SSF_TRANSMISSION))
|| (cos_dir_Ng < 0 && (type & SSF_REFLECTION))) {
@@ -655,7 +672,7 @@ update_mc
struct mc_receiver_1side* mc_samp_x_rcv1 = NULL;
res_T res = RES_OK;
ASSERT(pt && thread_ctx && point_is_receiver(pt));
-
+
res = point_dump(pt, irealisation, ibounce, output);
if(res != RES_OK) goto error;
@@ -775,7 +792,7 @@ trace_radiative_path
res = path_add_vertex(&path, pt.pos, pt.weight);
if(res != RES_OK) goto error;
}
-
+
#define ACCUM_WEIGHT(Res, W) { \
Res.weight += (W); \
Res.sqr_weight += (W)*(W); \
@@ -803,8 +820,8 @@ trace_radiative_path
if(mtl->type == SSOL_MATERIAL_VIRTUAL) {
point_hit_virtual(&pt);
} else {
- /* Modulate the point weight wrt to its scattering functions and
- * generate an outgoing direction */
+ /* Modulate the point weight wrt its scattering functions and generate
+ * an outgoing direction */
res = point_shade(&pt, thread_ctx->bsdf, &medium, thread_ctx->rng, pt.dir);
if(res != RES_OK) goto error;
}
