Update AOV support, ray intersection logic, and README

Added:
- AOV support for normals, albedo, and depth marked as completed.
- New function `normal_unpack` in `BSDF.h`.
- New field `esp` in `ray_t` structure in `RayIntersection.h`.

Changed:
- Updated `normal_ts_to_ws` to accept an additional parameter.
- Refactored `weight_nee_light` for clarity.
- Modified `RAY_EPSILON` for improved precision.
- Updated `path_output` structure to include a `normal` field.
- Normalized unpacked normal vector in `normal_unpack` function.
- Updated `path_trace` to use closest hit ray intersection.
- Updated `render_aov` to utilize closest hit logic.
- Modified `ray_create` to initialize `esp` based on ray origin.
- Improved accuracy in `offset_ray_origin` calculations.
- Updated ray intersection logic in `ray_intersect_triangle` and `ray_intersect_aabb` to include epsilon checks.
- Updated `evaluate_bsdf_directional` and `evaluate_bsdf_const_sky` for shadow rays.
- Adjusted `sample_bsdf_simple_lit` for incoming light direction calculations.
- Enhanced `render_pixel` to manage AOV flags effectively.
- Changed camera rotation and light intensity in `scene_setup`.
- Simplified texture loading by removing unnecessary sRGB conversion.

Modified:
- Several binary image files have been updated.

source/Algorithm/BSDF.c

@@ -34,20 +34,26 @@ vec3s normal_unpack(vec3s normal)
     float dot_xy = glm_clamp_zo(unpacked_normal.x * unpacked_normal.x + unpacked_normal.y * unpacked_normal.y);
     unpacked_normal.z = fmaxf(FLT_MIN, sqrtf(1.0f - dot_xy));
 
-    return unpacked_normal;
+    return glms_vec3_normalize(unpacked_normal);
 }
 
-vec3s normal_ts_to_ws(vec3s normal, vec3s tangent)
+vec3s normal_ts_to_ws(vec3s normal, vec3s geo_normal, vec3s tangent)
 {
-    vec3s t = glms_vec3_normalize(tangent);
-    vec3s b = glms_vec3_cross(normal, t);
+    tangent = glms_vec3_normalize(tangent);
+    vec3s bitangent = glms_vec3_cross(geo_normal, tangent);
+
+    float w = (glms_vec3_dot(glms_vec3_cross(geo_normal, tangent), bitangent) < 0.0f) ? -1.0f : +1.0f;
+
+    float proj = glms_vec3_dot(geo_normal, tangent);
+    vec3s t_prime = glms_vec3_normalize(glms_vec3_sub(tangent, glms_vec3_scale(geo_normal, proj)));
+    vec3s b_prime = glms_vec3_scale(glms_vec3_cross(geo_normal, t_prime), w);
 
     // Matrix in cglm is column-major, not row-major
     mat3s tbn =
     {
-        t.x, b.x, normal.x,
-        t.y, b.y, normal.y,
-        t.z, b.z, normal.z
+        t_prime.x, t_prime.y, t_prime.z,
+        b_prime.x, b_prime.y, b_prime.z,
+        geo_normal.x, geo_normal.y, geo_normal.z
     };
 
     return glms_vec3_normalize(glms_mat3_mulv(tbn, normal));
@@ -242,3 +248,12 @@ vec3s random_uniform_cdf_direction_angular(vec3s direction, uint32_t index, floa
     vec3s world_dir = glms_vec3_add(glms_vec3_add(term_u, term_v), term_w);
     return world_dir;
 }
+
+
+// Must use this function to weight any nee light contribution before accumulate.
+vec3s weight_nee_light(vec3s bsdf, vec3s light, float pdf_bsdf, float pdf_sky)
+{
+    light = glms_vec3_mul(bsdf, light);
+    float weight = power_heuristic(pdf_sky, pdf_bsdf);
+    return glms_vec3_scale(light, weight);
+}