solstice-solver

commit 514a3ee5f8734b7de79993116dc2a09061d1c7e1
parent 2888a852fbdc55ed2adc14db6f783d7d72d34def
Author: Christophe Coustet <christophe.coustet@meso-star.com>
Date:   Mon, 19 Sep 2016 13:33:52 +0200

BugFix: Reject some duplicate hits

Was on triangle's edge where the same hit was filtered twice.
Can lead to duplicate outputs.

Diffstat:
M
src/ssol_scene.c
 | 
9
+++++++++
M
src/ssol_solver.c
 | 
5
+++++
M
src/ssol_solver_c.h
 | 
1
+

3 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/src/ssol_scene.c b/src/ssol_scene.c
@@ -287,9 +287,17 @@ hit_filter_function
   /* these components have been set */
   ASSERT_NAN(seg->dir, 3);
   ASSERT_NAN(seg->org, 3);
+  ASSERT_NAN(&seg->tmin, 1);
   ASSERT(seg->self_instance);
   NCHECK(seg->self_front, 99);
 
+  /* need to reject identical hits on triangle's edges */
+  if (hit->distance <= seg->tmin) {
+    ASSERT(hit->distance == seg->tmin);
+    return 1;
+  }
+  seg->tmin = hit->distance;
+
   /* Discard self intersection */
   seg->hit_front = f3_dot(hit->normal, dir) < 0;
   inst = *htable_instance_find(&rs->data.scene->instances_rt, &hit->prim.inst_id);
@@ -374,6 +382,7 @@ hit_filter_function
   if(seg->hit_material->type == MATERIAL_VIRTUAL) {
     return 1; /* Discard virtual material */
   }
+
   seg->hit_instance = inst;
   return 0;
 }
diff --git a/src/ssol_solver.c b/src/ssol_solver.c
@@ -199,6 +199,7 @@ check_fst_segment(const struct segment* seg)
   NCHECK(seg->on_punched, 99);
   ASSERT_NAN(seg->org, 3);
   ASSERT(seg->weight > 0);
+  ASSERT_NAN(&seg->tmin, 1);
 }
 
 static void
@@ -238,6 +239,8 @@ setup_next_segment(struct realisation* rs)
   seg->self_instance = prev->hit_instance;
   seg->self_front = prev->hit_front;
   seg->sun_segment = 0;
+  seg->tmin = -1; /* any valid tmin allowed */
+
   d3_set(seg->org, prev->hit_pos);
   
   res = material_shade(prev->hit_material, &data->fragment, rs->freq, data->brdfs);
@@ -270,6 +273,7 @@ reset_segment(struct segment* seg)
   seg->self_instance = NULL;
   seg->self_front = 99;
   seg->weight = NAN;
+  seg->tmin = NAN;
 #else
   seg->hit = S3D_HIT_NULL;
 #endif
@@ -510,6 +514,7 @@ receive_sunlight(struct realisation* rs)
   seg->self_instance = start->instance;
   seg->self_front = start->front_exposed;
   seg->sun_segment = 1;
+  seg->tmin = -1; /* any valid tmin allowed */
 
   /* search for occlusions from starting point */
   ASSERT(rs->s_idx == 0); /* sun segment */
diff --git a/src/ssol_solver_c.h b/src/ssol_solver_c.h
@@ -66,6 +66,7 @@ struct segment {
   double hit_pos[3];
   double hit_pos_local[3]; /* in local coordinate, only set on punched shapes */
   double hit_normal[3]; /* possibly reversed to face the incoming dir */
+  float tmin; /* used to reject duplicate hits in raytracing */
   char hit_front; /* is the ending point of the segment on the front face? */
   char self_front; /* was the starting point of the segment on the front face? */
   char on_punched; /* is the hit on a punched shape? */