star-gf

commit 0dfae75c6705adbb51caba57462236719996e1ee
parent ddd8500078660a9a8f8d11bb5ab9b78c6cd804a8
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Wed,  6 Jul 2016 11:43:29 +0200

Upd the self hit management and incr the lib verbosity

Diffstat:
M
src/sgf_estimator.c
 | 
56
++++++++++++++++++++++++++++++++++++++++++++++----------

1 file changed, 46 insertions(+), 10 deletions(-)
diff --git a/src/sgf_estimator.c b/src/sgf_estimator.c
@@ -13,6 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>. */
 
+#define _POSIX_C_SOURCE 200112L /* nextafterf support */
+
 #include "sgf.h"
 #include "sgf_device_c.h"
 
@@ -38,6 +40,10 @@ struct accum {
 #define DARRAY_DATA struct accum
 #include <rsys/dynamic_array.h>
 
+/* How many self intersections are tested on the same ray before an error
+ * occurs */
+#define NSELF_HITS_MAX 10
+
 /* Estimator of the Gebhart Factor of a given face to all the other ones */
 struct sgf_estimator {
   struct darray_accum buf; /* Integrated radiative flux of each primitive */
@@ -88,16 +94,18 @@ setup_status
 /* Return RES_BAD_OP on numerical issue. i.e. the radiative path is skipped */
 static res_T
 gebhart_radiative_path
-  (struct accum* accums,
+  (struct sgf_device* dev,
+   struct accum* accums,
    struct accum* accums_infinity,
    struct ssp_rng* rng,
+   const float epsilon,
    const size_t primitive_id,
    struct sgf_scene_desc* desc)
 {
   struct s3d_hit hit;
   struct s3d_primitive prim_from, prim;
   struct s3d_attrib attrib;
-
+  size_t nself_hits = 0;
   const double trans_min = 1.e-8; /* Minimum transmissivity threshold */
   double proba_reflec_spec;
   double transmissivity, emissivity, reflectivity, specularity;
@@ -105,7 +113,6 @@ gebhart_radiative_path
   double infinite_radiative_flux = 0.0;
   double sum_radiative_flux = 0.f;
 #endif
-
   float st[2] = {0.f, 0.f}; /* Parametric coordinate of the sampled position */
   float vec0[3]; /* Temporary vector */
   float normal[3]; /* Geometric normal */
@@ -114,7 +121,7 @@ gebhart_radiative_path
   float range[2]; /* Traced ray range */
   float u, v;
 
-  ASSERT(accums && accums_infinity && rng && desc);
+  ASSERT(accums && accums_infinity && epsilon > 0.f && rng && desc);
 
   /* Discard faces with no emissivity */
   emissivity = desc->get_material_property(desc->material,
@@ -140,14 +147,24 @@ gebhart_radiative_path
 
   transmissivity = 1.0;
   for(;;) { /* Here we go */
-
     prim_from = prim;
-    range[0] = 1.e-6f, range[1] = FLT_MAX;
+    range[0] = epsilon, range[1] = FLT_MAX;
 
-    for(;;) {
+    nself_hits = 0;
+    do { /* Handle auto intersection */
       S3D(scene_trace_ray(desc->scene, pos, dir, range, NULL, &hit));
-      if(S3D_PRIMITIVE_EQ(&hit.prim, &prim_from)) range[0] += 1.e-6f; /* Self hit */
-      else break;
+      if(!S3D_HIT_NONE(&hit)) range[0] = MMAX(range[0], hit.distance);
+      range[0] = nextafterf(range[0], range[1]);
+    } while(S3D_PRIMITIVE_EQ(&hit.prim, &prim_from) /* Self hit */
+         && ++nself_hits < NSELF_HITS_MAX); /* Too many self hits */
+
+    if(nself_hits >= NSELF_HITS_MAX) {
+      if(dev->verbose) {
+        logger_print(dev->logger, LOG_ERROR,
+          "Too many self hit on a given ray. Ray origin: %g, %g, %g\n",
+          SPLIT3(pos));
+      }
+      return RES_BAD_OP;
     }
 
     if(S3D_HIT_NONE(&hit)) { /* The ray is outside the volume */
@@ -321,6 +338,8 @@ sgf_integrate
   size_t istep;
   size_t ispectral_band;
   size_t nprims;
+  float epsilon;
+  float lower[3], upper[3];
   int mask;
   res_T res = RES_OK;
 
@@ -355,6 +374,22 @@ sgf_integrate
     goto error;
   }
 
+  /* Compute an epsilon relatively to the scene size */
+  S3D(scene_get_aabb(desc->scene, lower, upper));
+  epsilon = upper[0] - lower[0];
+  epsilon = MMIN(epsilon, upper[1] - lower[1]);
+  epsilon = MMIN(epsilon, upper[2] - lower[2]);
+  if(epsilon <= 0.f) {
+    if(dev->verbose) {
+      logger_print(dev->logger, LOG_ERROR,
+        "Degenerated scene geometry. lower: %g, %g, %g; upper: %g %g %g\n",
+        SPLIT3(lower), SPLIT3(upper));
+    }
+    res = RES_BAD_ARG;
+    goto error;
+  }
+  epsilon = MMAX(epsilon*1.e-6f, FLT_MIN);
+
   /* Allocate and init the Gebhart Factor result buffer */
   res = darray_accum_resize(&estimator->buf, nprims*desc->spectral_bands_count);
   if(res != RES_OK) {
@@ -380,6 +415,7 @@ sgf_integrate
   memset(darray_accum_data_get(&estimator->buf_infinity), 0,
     darray_accum_size_get(&estimator->buf_infinity)*sizeof(struct accum));
 
+
   /* Invoke the Gebhart factor integration. */
   FOR_EACH(ispectral_band, 0, desc->spectral_bands_count) {
     struct accum* accums =
@@ -389,7 +425,7 @@ sgf_integrate
 
     FOR_EACH(istep, 0, steps_count) {
       res = gebhart_radiative_path
-        (accums, accums_infinity, rng, primitive_id, desc);
+        (dev, accums, accums_infinity, rng, epsilon, primitive_id, desc);
       if(res != RES_OK) goto error;
     }
   }