star-schiff

commit 0889a42b7073b16a470157e8755f8f85219b96d2
parent 7855c7c4d96c776016bd5623ce6ccfaa3c49fea6
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Mon, 19 Oct 2015 15:15:12 +0200

Add some minor comments

Diffstat:
M
src/sschiff.h
 | 
4
+++-
M
src/sschiff_estimator.c
 | 
18
++++++++++++------

2 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/src/sschiff.h b/src/sschiff.h
@@ -56,7 +56,7 @@ struct s3d_device;
 struct s3d_shape;
 struct ssp_rng;
 
-/* Optical properties of a material handled by the Schiff integrator. */
+/* Optical properties of a material handled by the Schiff integrator */
 struct sschiff_material_properties {
   double medium_refractive_index;
   double relative_real_refractive_index;
@@ -75,6 +75,7 @@ struct sschiff_material {
 
 static const struct sschiff_material SSCHIFF_NULL_MATERIAL = { NULL, NULL };
 
+/* User defined distribution of the geometries */
 struct sschiff_geometry_distribution {
   res_T (*sample) /* Sample a geometry i.e. a shape and its material */
     (struct ssp_rng* rng,
@@ -159,6 +160,7 @@ sschiff_estimator_get_average_projected_area
   (struct sschiff_estimator* estimator,
    struct sschiff_estimator_status* status);
 
+/* TODO Not implemented yet */
 SSCHIFF_API res_T
 sschiff_estimator_get_phase_function
   (struct sschiff_estimator* estimator,
diff --git a/src/sschiff_estimator.c b/src/sschiff_estimator.c
@@ -221,9 +221,12 @@ compute_monte_carlo_weight
   /* Compute the origin of the projection plane */
   f3_add(org, pos, f3_mulf(org, axis_z, lower[2]));
 
-  /* Uniformly sample a position onto the projection plane and use it as the
-   * origin of the ray to trace */
+  FOR_EACH(i, 0, WEIGHTS_COUNT)
+    weights[i] = 0;
+
   do {
+    /* Uniformly sample a position onto the projection plane and use it as the
+     * origin of the ray to trace */
     sample[0] = ssp_rng_uniform_double(rng, -1.0, 1.0);
     sample[1] = ssp_rng_uniform_double(rng, -1.0, 1.0);
     f3_mulf(x, axis_x, (float)sample[0]);
@@ -232,14 +235,13 @@ compute_monte_carlo_weight
 
     S3D(scene_trace_ray(scn, ray_org, axis_z, range, &hit));
 
-    FOR_EACH(i, 0, WEIGHTS_COUNT) weights[i] = 0;
     if(!S3D_HIT_NONE(&hit)) {
       double n_r, k_r;
       double n_e, k_e, lambda_e;
       double path_length;
 
       res = compute_path_length(dev, scn, &hit, ray_org, axis_z, &path_length);
-      if(res != RES_OK) {
+      if(res != RES_OK) { /* Handle numerical/geometry issues */
         ++nfailures;
         continue;
       }
@@ -264,6 +266,7 @@ compute_monte_carlo_weight
       weights[WEIGHT_AVERAGE_PROJECTED_AREA] = rcp_pdf;
     }
   } while(res != RES_OK && nfailures < MAX_FAILURES);
+
   if(res != RES_OK) {
     log_error(dev,
 "Too many failures in computing the radiative path length. The sampled geometry\n"
@@ -272,7 +275,7 @@ compute_monte_carlo_weight
   return res;
 }
 
-/* Cast rays into the RT volume */
+/* Dump a thumbnail of the sampled geometry in given sampled direction */
 static INLINE void
 draw_thumbnail
   (struct s3d_scene* scn,
@@ -420,8 +423,8 @@ radiative_properties
 
     FOR_EACH(i, 0, WEIGHTS_COUNT) weights_dirs[i] += weights[i];
 #if 0
-    /* Compute an image of the shape transformed in the footprint space */
     {
+      /* Compute an image of the shape transformed in the footprint space */
       char thumb_name[64];
       sprintf(thumb_name, "%d_%lu.ppm", istep, idir);
       draw_thumbnail(scene, basis, centroid, lower, upper, thumb_name);
@@ -553,6 +556,7 @@ sschiff_integrate
     struct sschiff_material material = SSCHIFF_NULL_MATERIAL;
     struct sschiff_material_properties props;
 
+    /* Sample a geometry, i.e. a shape and its associated material */
     res = distrib->sample(rng, &material, shape, distrib->context);
     if(res != RES_OK) {
       log_error(dev, "Error in sampling a Schiff geometry.\n");
@@ -560,8 +564,10 @@ sschiff_integrate
     }
     material.get_property(material.material, wavelength, &props);
 
+    /* Build the Star-3D representation of the sampled shape */
     S3D(scene_begin_session(scene, S3D_TRACE));
 
+    /* Schiff Estimation */
     res = radiative_properties(dev, rng, (int)i, wavelength,
       sampled_directions_count, scene, &props, estimator->accums);
     if(res != RES_OK) goto error;