From: Lukas Jiriste <ljiriste@student.42prague.com>
Date: Tue, 26 Nov 2024 19:16:04 +0000 (+0100)
Subject: Solve plane shadow acne
X-Git-Url: https://git.ljiriste.work/?a=commitdiff_plain;h=becb4660efcfb74579afe77d0a22c13684230db2;p=42%2FminiRT.git

Solve plane shadow acne

This commit makes it so an object does not use itself for shadow
calculation. This only works properly for objects, that are not concave.
---

diff --git a/src/scene.c b/src/scene.c
index 2b112d9..b7cc7aa 100644
--- a/src/scene.c
+++ b/src/scene.c
@@ -207,10 +207,12 @@ double	get_intersection_arg(const t_ray *ray, const t_object *object)
 		return (get_intersection_arg_bounded(ray, object));
 }
 
-const t_object	*find_nearest_object(const t_ray *ray, const t_vec *objects)
+const t_object	*find_nearest_object(const t_ray *ray, const t_vec *objects,
+					const t_object *ignored)
 {
 	size_t			i;
 	const t_object	*object_found;
+	const t_object	*object;
 	double			distance_found;
 	double			distance;
 
@@ -219,13 +221,15 @@ const t_object	*find_nearest_object(const t_ray *ray, const t_vec *objects)
 	i = 0;
 	while (i < objects->size)
 	{
-		distance = get_intersection_arg(ray, ft_vec_caccess(objects, i));
+		object = ft_vec_caccess(objects, i++);
+		if (object == ignored)
+			continue ;
+		distance = get_intersection_arg(ray, object);
 		if (0 < distance && distance < distance_found)
 		{
 			distance_found = distance;
-			object_found = ft_vec_caccess(objects, i);
+			object_found = object;
 		}
-		++i;
 	}
 	return (object_found);
 }
@@ -282,7 +286,7 @@ t_color	get_light_contribution(t_vec3 point, const t_object *object, const t_lig
 
 	new_ray.start = point;
 	new_ray.direction = vec_diff(light->position, new_ray.start);
-	obstruction = find_nearest_object(&new_ray, &scene->objects);
+	obstruction = find_nearest_object(&new_ray, &scene->objects, object);
 	normal = get_object_normal(object, point);
 	angle_multiplier = vec_scalar_mul(normal, new_ray.direction)
 		/ (vec_norm(normal) * vec_norm(new_ray.direction));
@@ -323,7 +327,7 @@ t_color	trace_ray(const t_ray *ray, const t_scene *scene)
 {
 	const t_object	*object_found;
 
-	object_found = find_nearest_object(ray, &scene->objects);
+	object_found = find_nearest_object(ray, &scene->objects, NULL);
 	if (object_found)
 		return (get_object_color(ray, object_found, scene));
 	else