Merge pull request #17 from Morozov-5F/bugfix/fix-rotation-bug

[#4] Fix the rotation bug due to incorrect front face setting.
Morozov-5F · Nov 28, 2021 · 35012e4 · 35012e4
2 parents 92cec70 + a2b5452
commit 35012e4
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Showing 2 changed files with 7 additions and 10 deletions.
diff --git a/hittables/rt_instance.c b/hittables/rt_instance.c
@@ -86,7 +86,7 @@ static bool rt_instance_hit(const rt_hittable_t *hittable, const ray_t *ray, dou
     vec3_add(&record->p, instance->offset);
 
     vec3_t new_normal = rt_mat3_mul_vec3(&instance->transform_matrix_bb, &record->normal);
-    rt_hit_record_set_front_face(record, &transformed_ray, &new_normal);
+    rt_hit_record_set_front_face(record, ray, &new_normal);
 
     return true;
 }
@@ -105,8 +105,6 @@ static bool rt_instance_bb(const rt_hittable_t *hittable, double time0, double t
         return false;
     }
 
-    hittable_bb = rt_aabb(vec3_sum(hittable_bb.min, instance->offset), vec3_sum(hittable_bb.max, instance->offset));
-
     vec3_t min = hittable_bb.min, max = hittable_bb.max;
     for (int i = 0; i < 2; i++)
     {
@@ -119,7 +117,6 @@ static bool rt_instance_bb(const rt_hittable_t *hittable, double time0, double t
                                         k * hittable_bb.max.z + (1 - k) * hittable_bb.min.z);
 
                 vec3_t tester = rt_mat3_mul_vec3(&instance->transform_matrix_bb, &point);
-
                 for (int c = 0; c < 3; c++)
                 {
                     min.components[c] = fmin(min.components[c], tester.components[c]);
@@ -128,8 +125,7 @@ static bool rt_instance_bb(const rt_hittable_t *hittable, double time0, double t
             }
         }
     }
-
-    *out_bb = rt_aabb(min, max);
+    *out_bb = rt_aabb(vec3_sum(min, instance->offset), vec3_sum(max, instance->offset));
 
     return true;
 }

diff --git a/scenes/rt_scenes.c b/scenes/rt_scenes.c
@@ -179,8 +179,8 @@ rt_hittable_list_t *rt_scene_instance_test(void)
 
     rt_hittable_t *box = rt_box_new(point3(-1, -1, -1), point3(1, 1, 1), green);
     rt_hittable_t *instance = rt_instance_new(box);
-    rt_instance_rotate_y(instance, 0);
-    rt_instance_translate(instance, point3(1, 0, 0));
+    rt_instance_rotate_y(instance, 45);
+    rt_instance_translate(instance, point3(1, 0, 0.1));
 
     rt_hittable_list_add(objects, instance);
     rt_hittable_list_add(objects, rt_box_new(point3(-0.25, -0.25, -0.25), point3(0.25, 0.25, 0.25), red));
@@ -332,8 +332,9 @@ rt_hittable_list_t *rt_scene_metal_test(void)
     rt_hittable_list_add(objects, rt_sphere_new(point3(2, 2, 0), 1, rt_mt_metal_new(colour(0.8, 0.8, 0.9), 1.0)));
 
     rt_hittable_t *box_instance =
-        rt_instance_new(rt_box_new(point3(-1, 0, 10), point3(1, 2, 12), rt_mt_metal_new(colour(0.8, 0.8, 0.9), 0.0)));
-    rt_instance_rotate_y(box_instance, 10);
+        rt_instance_new(rt_box_new(point3(-1, -1, -1), point3(1, 1, 1), rt_mt_metal_new(colour(0.8, 0.8, 0.9), 0.0)));
+    rt_instance_rotate_y(box_instance, 45);
+    rt_instance_translate(box_instance, vec3(2, 1, 11));
     rt_hittable_list_add(objects, box_instance);
 
     return objects;