commit be688d494a1d919d71f9683f1193386d1b9402ca
parent a51410c83da1e972f0c26bb9f7316e566d0bc822
Author: Eduardo Fontana Lazzari <edufonlaz@gmail.com>
Date: Wed, 14 Jan 2026 15:13:16 +0100
Continue refactoring of realization function
This commit makes a series of minor modifications in the
compute_MVREA_realization function in order to improve semantic clarity
(sort local variables, explicit ambiguous inputs and outputs in function
calls, simplify error handling...).
Also, the wavelength is no longer a member variable of the ray structure,
but is a local variable in the realization function. This makes the ray a
purely geometry-related structure, used exclusively in the intersection
search procedure.
Diffstat:
3 files changed, 86 insertions(+), 124 deletions(-)
diff --git a/src/sphor_compute_mvrea.c b/src/sphor_compute_mvrea.c
@@ -508,8 +508,8 @@ error:
static res_T
setup_bsdf_from_refractive_indices
(struct sphor* sphor,
- struct ray* ray,
struct intersection* intersection,
+ double wavelength,
struct ssf_bsdf** out_bsdf)
{
double n_real_i = 0, n_imag_i = 0;
@@ -519,17 +519,16 @@ setup_bsdf_from_refractive_indices
res_T res = RES_OK;
ASSERT(NULL != sphor);
- ASSERT(NULL != ray);
ASSERT(NULL != intersection);
/* Get refractive index of the medium in the incident side */
res = primitive_get_in_refraction_index
- (sphor, primitive, ray->wavelength, &n_real_i, &n_imag_i);
+ (sphor, primitive, wavelength, &n_real_i, &n_imag_i);
if (RES_OK != res){ goto error; }
/* Get refractive index of the medium in the transmitted side */
res = primitive_get_out_refraction_index
- (sphor, primitive, ray->wavelength, &n_real_t, &n_imag_t);
+ (sphor, primitive, wavelength, &n_real_t, &n_imag_t);
if (RES_OK != res){ goto error; }
/* Sample an interaction type and a new direction using ssf */
@@ -555,6 +554,7 @@ sample_interface_ray_interaction
struct ssp_rng* rng,
struct ray* ray,
struct intersection* intersection,
+ double wavelength,
double dir[3],
enum ray_interface_interaction_type* interaction_type)
{
@@ -605,7 +605,7 @@ sample_interface_ray_interaction
* index of each side of the interface to construct the BRDF */
else {
res = setup_bsdf_from_refractive_indices
- (sphor, ray, intersection, &bsdf);
+ (sphor, intersection, wavelength, &bsdf);
if (RES_OK != res){ goto error; }
}
@@ -664,56 +664,70 @@ compute_MVREA_realization
struct htable_accum2id* accum2id,
struct darray_accum* accums)
{
- double dir[3] = {0}; /* Current direction in path sampling */
- double response_function = 0;
- double ka = 0;
- double s = 0; /* Random number */
+ /* Star-Phor Input */
+ struct sphin_sensor_volume* sensor_volume = NULL;
+ struct sphin_sensor_surface* sensor_surface = NULL;
+ struct sphin_volume* volume = NULL;
+
+ /* The sampled source */
+ struct source_view* source_view = NULL;
+
+ /* Ray */
enum ray_interface_interaction_type ray_interface_interaction_type =
RAY_INTERFACE_INTERACTION_NONE__;
struct intersection intersection = INTERSECTION_NULL;
struct ray ray = RAY_DEFAULT;
- struct source_view* source_view = NULL;
- struct sphin_sensor_volume* sensor_volume = NULL;
- struct sphin_sensor_surface* sensor_surface = NULL;
- struct sphin_volume* volume = NULL;
+
+ /* Miscellaneous */
+ double dir[3] = {0}; /* Sampled direction during path sampling */
+ double response_function = 0;
+ double ka = 0;
+ double free_path = 0;
+ double wavelength = 0;
+ int stop = 0;
+
+ /* For error management */
res_T res = RES_OK;
+ #define CALL(Function) { \
+ res = Function; \
+ if(RES_OK != res) goto error; \
+ } (void)0
+ /* Pre-conditions */
ASSERT(NULL != sphor);
ASSERT(NULL != rng);
ASSERT(NULL != accum2id);
ASSERT(NULL != accums);
/* Sample a random position from a source in the whole scene */
- res = sample_source_position
- (sphor, rng, &source_view, &ray.origin_on_prim, ray.origin);
- if (RES_OK != res){ goto error; }
+ CALL(sample_source_position(sphor,
+ /* in: */ rng,
+ /* out: */ &source_view, &ray.origin_on_prim, ray.origin));
/* Sample a direction according to the source direction distribution */
- res = source_surface_sample_direction
- (sphor, rng, &ray.origin_on_prim, ray.direction);
- if (RES_OK != res){ goto error; }
+ CALL(source_surface_sample_direction(sphor,
+ /* in: */ rng, &ray.origin_on_prim,
+ /* out: */ ray.direction));
/* Sample a wavelength according to the source emission spectrum */
- res = source_sample_wavelength
- (sphor, rng, source_view, &ray.wavelength);
- if (RES_OK != res){ goto error; }
+ CALL(source_sample_wavelength
+ (sphor, rng, source_view, &wavelength));
+ /* Retrieve the volume defined by the sampled primitive */
volume = volume_get_from_primitive(sphor, &ray.origin_on_prim.primitive);
/* Retrieve the ka of the present volume */
- res = volume_compute_total_ka(sphor, volume, ray.wavelength, &ka);
- if (RES_OK != res){ goto error; }
+ CALL(volume_compute_total_ka(sphor, volume, wavelength, &ka));
/* While no absorption takes place and an interface is found */
- for(;;) {
+ while(!stop) {
/* Sample the free path length to absorption from an exponential
* distribution with rate parameter ka */
- s = ssp_ran_exp(rng, ka);
+ free_path = ssp_ran_exp(rng, ka);
/* Trace a ray in the scene from the sampled primitive in the sampled
* direction and retrive the hit distance */
- res = trace_ray(sphor, &ray, &intersection);
- if (RES_OK != res){ goto error; }
+ CALL(trace_ray(sphor, &ray, &intersection));
/* If there is no intersection in the sampled direction from the sampled
* position, the photon is lost and it counts zero in the weight. */
@@ -722,11 +736,10 @@ compute_MVREA_realization
/* If the distance between the ray origin and the intersection is bigger
* than the absorption free path length, an absorption takes place (check
* if the volume is a sensor and return the weight accordingly) */
- if (s < intersection.distance) {
- /* Check if the volume is a sensor */
- res = sphin_volume_get_sensor(volume, &sensor_volume);
- if (RES_OK != res){ goto error; }
+ if (free_path < intersection.distance) {
+ CALL(sphin_volume_get_sensor(volume, &sensor_volume));
+ /* Check if the volume is a sensor */
if (NULL == sensor_volume) {
/* If the volume is not a sensor, the absorbed photon does not count in
* the weight. The weight is implictly 0 */
@@ -734,27 +747,28 @@ compute_MVREA_realization
/* If the volume is a sensor, compute the weight using the response
* function */
- /* TODO res = update_mc_weights(...); */
+ /* TODO res = update_mc_weights_MVREA_volume(...,mc_weight,...); */
struct accum_key accum_key = ACCUM_KEY_NULL;
size_t prop_rad_count = 0;
size_t volume_id = SIZE_MAX;
size_t i_proprad = 0;
- double vol = 0;
+ double vol_size = 0;
double tot_pow = 0;
double mc_weight = 0;
- res = sphin_sensor_volume_get_response_function
- (sensor_volume, &response_function);
- if (RES_OK != res){ goto error; }
- res = sphin_volume_compute_total_volume(volume, &vol);
+ /* Get the total three-dimensional space occupied by the volume */
+ res = sphin_volume_compute_total_size(volume, &vol_size/*[m^3]*/);
if (RES_OK != res){ goto error; }
res = sphin_config_get_total_surface_power(sphor->config, &tot_pow);
if (RES_OK != res){ goto error; }
+
+ mc_weight = tot_pow / vol_size;
+ res = sphin_sensor_volume_get_response_function
+ (sensor_volume, &response_function);
+ if (RES_OK != res){ goto error; }
res = sphin_volume_get_prop_rad_count(volume, &prop_rad_count);
if (RES_OK != res){ goto error; }
- mc_weight = tot_pow / vol;
-
volume_id = intersection.position.primitive.interface->volumes
[intersection.position.primitive.side];
@@ -777,81 +791,62 @@ compute_MVREA_realization
struct sphin_prop_rad* prop_rad = NULL;
res = sphin_volume_get_prop_rad(volume, i_proprad, &prop_rad);
if (RES_OK != res){ goto error; }
- res = prop_rad_compute_ka(prop_rad, ray.wavelength, &ka_i);
+ res = prop_rad_compute_ka(prop_rad, wavelength, &ka_i);
if (RES_OK != res){ goto error; }
accum_key.component_id = i_proprad;
- mc_weight = ka_i / ka * tot_pow / vol;
+ mc_weight = ka_i / ka * tot_pow / vol_size;
update_accum(accum2id, &accum_key, mc_weight, accums);
}
}
/* Absorption => stop the path */
- break;
- }
-
- /* Else, the distance between the ray origin and the intersection is smaller
- * than the absorption free path length. The photon intersects a primitive
- * in the scene view. Sample the type of interaction that the photon has
- * with the interface as well as the new direction sampled */
- res = sample_interface_ray_interaction
- (sphor, rng, &ray, &intersection, dir, &ray_interface_interaction_type);
- if (RES_OK != res){ goto error; }
-
- int stop = 0;
- switch (ray_interface_interaction_type) {
- /* An absorption took place, the weight is zero and the path stops */
- case RAY_INTERFACE_INTERACTION_ABSORPTION:
+ stop = 1;
+
+ } else {
+ /* Else, the distance between the ray origin and the intersection is
+ * smaller than the absorption free path length. The photon intersects a
+ * primitive in the scene view. Sample the type of interaction that the
+ * photon has with the interface as well as the new direction sampled */
+ CALL(sample_interface_ray_interaction(sphor,
+ /* in: */ rng, &ray, &intersection, wavelength,
+ /* out: */ dir, &ray_interface_interaction_type));
+
+ if(RAY_INTERFACE_INTERACTION_ABSORPTION == ray_interface_interaction_type) {
/* TODO: verify if surface is sensor and update its accum
- res = primitive_get_sensor_surface(sphor, &intersection.position.primitive, &sensor_surface);
- if (RES_OK != res){ goto error; } */
+ res = primitive_get_sensor_surface(sphor,
+ &intersection.position.primitive, &sensor_surface); if (RES_OK !=
+ res){ goto error; } */
/* If the volume is a sensor, compute the weight using the response
* function */
- if (NULL != sensor_surface)
- {
- /* res = update_mc_weights(...= */
- }
- stop = 1;
- break;
+ if (NULL != sensor_surface){
+ /* res = update_mc_weights_surface_MVREA(...= */
+ }
- /* Else, if a reflection takes place, sample a new direction according to
- * the photon arriving direction, geometry normak and surface brdf
- * properties */
- case RAY_INTERFACE_INTERACTION_REFLECTION:
- break;
+ /* Absorption => stop the path */
+ stop = 1;
- /* If the ray traverses the interface, it simply continue in the same
- * direction as before */
- case RAY_INTERFACE_INTERACTION_TRANSMISSION:
+ } else if(RAY_INTERFACE_INTERACTION_TRANSMISSION == ray_interface_interaction_type) {
/* Continue the path on the other side of the primitive.*/
intersection.position.primitive.side =
!intersection.position.primitive.side;
+ CALL(ray_update(/* in/out: */ &ray, /* in: */ &intersection, dir));
+
/* Update the current medium */
volume = volume_get_from_primitive
(sphor, &intersection.position.primitive);
- /* Retrieve the ka of the present volume */
- res = volume_compute_total_ka(sphor, volume, ray.wavelength, &ka);
- if (RES_OK != res){ goto error; }
- break;
-
- /* Handle the possible exceptions */
- case RAY_INTERFACE_INTERACTION_NONE__:
- res = RES_BAD_ARG;
- goto error;
- default:
- FATAL("Unreachable code\n");
- break;
- }
- if (stop) { break; }
-
- /* Update ray with the intersection information */
- res = ray_update(&ray, &intersection, dir);
- if (RES_OK != res){ goto error; }
+ CALL(volume_compute_total_ka(sphor, volume, wavelength, &ka));
+ } else if(RAY_INTERFACE_INTERACTION_REFLECTION == ray_interface_interaction_type) {
+ CALL(ray_update(/* in/out: */ &ray, /* in: */ &intersection, dir));
+ }
+ }
}
+ #undef CALL
+
exit:
return res;
error:
diff --git a/src/sphor_interface.c b/src/sphor_interface.c
@@ -384,27 +384,3 @@ ray_update
d3_set(ray->direction, dir);
return res;
}
-
-res_T
-interface_get_side_id
- (const double dir[3], /* Direction of arrival of the hit into the geometry */
- const struct s3d_hit* hit,
- enum sphin_side* side)
-{
- double normal[3] = {0};
- res_T res = RES_OK;
-
- ASSERT(NULL != dir);
- ASSERT(NULL != side);
-
- /* hit->normal: unormalized hit normal that uses the left hand convention */
- d3_normalize(normal, d3_set_f3(normal, hit->normal));
-
- /* Test the angle between the two vectors dir and normal using the dot
- * product. If it is negative, the S3D normal points to the hemisphere of the
- * arriving hit, which corresponds to the BACK side in the sphin convention.
- * Otherwise, it corresponds to the front side. */
- *side = (d3_dot(dir, normal) < 0 ) ? SPHIN_SIDE_BACK : SPHIN_SIDE_FRONT;
-
- return res;
-}
diff --git a/src/sphor_interface.h b/src/sphor_interface.h
@@ -86,7 +86,6 @@ static const struct intersection INTERSECTION_NULL = INTERSECTION_NULL__;
struct ray {
double origin[3];
double direction[3];
- double wavelength;
double range[2];
/* Origin of the ray when located on a primitive.
@@ -96,7 +95,6 @@ struct ray {
#define RAY_DEFAULT__ { \
{0,0,0}, \
{0,0,0}, \
- DBL_MAX, \
{0, DBL_MAX}, \
PRIMITIVE_POS_NULL__ \
}
@@ -148,11 +146,4 @@ ray_update
const struct intersection* intersection,
const double dir[3]);
-/* TODO this should disappear */
-extern LOCAL_SYM res_T
-interface_get_side_id
- (const double dir[3],
- const struct s3d_hit* hit,
- enum sphin_side* side);
-
#endif /* SPHOR_INTERFACE_H */
