star-gf

commit 34fa20a0f072059f098580c4a8c0a38d6847fe1c
parent 2e9b98a63d2d7eaab762a53cd6d2e8e5d278e117
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Fri, 11 Sep 2015 16:17:33 +0200

Handle radiative paths that does not intersect a geometry

Their transmissivity is accumulated into the "environment". This value
is added the overall distributed transmissivity when the "energy
conservation" property is checked.

Diffstat:
M
src/sgf.c
 | 
54
++++++++++++++++++++----------------------------------

1 file changed, 20 insertions(+), 34 deletions(-)
diff --git a/src/sgf.c b/src/sgf.c
@@ -57,16 +57,16 @@ gebhart_radiative_path
 {
   struct s3d_hit hit;
   struct sgf_accum* gebfac; /* Gebhart factor */
-  struct s3d_primitive prim;
+  struct s3d_primitive prim_from, prim;
   struct s3d_attrib attrib;
   float st[2] = {0.f, 0.f};
+  double sky_gebhart = 0.0;
   double transmissivity = 1.0;
   double proba_reflec_spec;
   double emissivity;
   double reflectivity;
   double specularity;
   const double trans_min = 1.e-8;
-  size_t iprim, iprim_from;
   size_t nprims;
   float vec0[3];
   float normal[3];
@@ -99,42 +99,40 @@ gebhart_radiative_path
    * `normal' */
   ssp_ran_hemisphere_cos(rng, normal, dir);
 
-  iprim = ctx->primitive_id;
   transmissivity = 1.0;
+  sky_gebhart = 0.0;
 
   for(;;) { /* Here we go */
-    iprim_from = iprim;
+    prim_from = prim;
 
-    range[0] = FLT_MIN, range[1] = FLT_MAX;
+    range[0] = 1.e-6f, range[1] = FLT_MAX;
     for(;;) {
       S3D(scene_trace_ray(ctx->scene, pos, dir, range, &hit));
-      if(hit.prim.prim_id == iprim_from) range[0] += FLT_EPSILON; /* Self hit */
+      if(S3D_PRIMITIVE_EQ(&hit.prim, &prim_from)) range[0] += 1.e-6f; /* Self hit */
       else break;
 
     }
 
     if(S3D_HIT_NONE(&hit)) {
-      if(ctx->verbose) {
-        logger_print(ctx->logger, LOG_OUTPUT, "Unexpected radiative path failure\n");
-        return RES_BAD_OP;
-      }
+      sky_gebhart += transmissivity;
+      break;
     }
     f3_normalize(normal, hit.normal);
 
     /* Retrieve the hit position and the hit primitive id */
     f3_mulf(vec0, dir, hit.distance);
     f3_add(pos, vec0, pos);
-    iprim = hit.prim.prim_id;
+    prim = hit.prim;
 
-    /* Fetch material property */
+    /* Fetch material property. TODO fix the use of the prim_id */
     emissivity = ctx->get_material_property
-      (ctx->material, SGF_MATERIAL_EMISSIVITY, iprim, ispectral_band);
+      (ctx->material, SGF_MATERIAL_EMISSIVITY, prim.prim_id, ispectral_band);
     specularity = ctx->get_material_property
-      (ctx->material, SGF_MATERIAL_SPECULARITY, iprim, ispectral_band);
+      (ctx->material, SGF_MATERIAL_SPECULARITY, prim.prim_id, ispectral_band);
     reflectivity = ctx->get_material_property
-      (ctx->material, SGF_MATERIAL_REFLECTIVITY, iprim, ispectral_band);
+      (ctx->material, SGF_MATERIAL_REFLECTIVITY, prim.prim_id, ispectral_band);
 
-    gebfac = result + iprim * ctx->spectral_bands_count;
+    gebfac = result + prim.prim_id * ctx->spectral_bands_count;
     if(transmissivity > trans_min) {
       const double weight = transmissivity * emissivity;
       gebfac[ispectral_band].radiative_flux += weight;
@@ -169,11 +167,13 @@ gebhart_radiative_path
 #if !defined(NDEBUG)
   { /* Ensure the energy conservation property */
     double sum_radiative_flux = 0.0;
+    size_t iprim;
     gebfac = result;
     FOR_EACH(iprim, 0, nprims) {
       sum_radiative_flux += gebfac[ispectral_band].radiative_flux;
       gebfac += ctx->spectral_bands_count;
     }
+    sum_radiative_flux += sky_gebhart;
     ASSERT(eq_eps(sum_radiative_flux, 1.0, 1.e-6));
   }
 #endif
@@ -188,29 +188,15 @@ gebhart_factor_integrand
 {
   struct sgf_context* ctx = context;
   struct sgf_accum* buf;
-  size_t nfailures = 0;
   size_t iband = 0;
-  res_T res = RES_OK;
+  res_T res = RES_OK; (void)res;
   ASSERT(result && rng && context);
 
   buf = darray_gfacc_data_get(result);
   FOR_EACH(iband, 0, ctx->spectral_bands_count) {
-    do {
-      accum_buffer_clear(result);
-      res = gebhart_radiative_path(buf, rng, ctx, iband);
-    } while(res == RES_BAD_OP && (++nfailures < MAX_FAILURES));
-
-    if(ctx->verbose) {
-      if(nfailures >= MAX_FAILURES) {
-        logger_print(ctx->logger, LOG_ERROR,
-"Too many radiative path failures. The geometry might be wrongly setuped. The\n"
-"geometry should be closed and 2D-manifold. In addition its normals must point\n"
-"*into* the volume with respect to a Clock Wise vertex ordering\n");
-      } else if(res != RES_OK) {
-        logger_print(ctx->logger, LOG_ERROR,
-          "Critical error in the computation of the Gebhart factor\n");
-      }
-    }
+    accum_buffer_clear(result);
+    res = gebhart_radiative_path(buf, rng, ctx, iband);
+    ASSERT(res == RES_OK);
   }
 }