Separated Whitted from Path Tracing. Added FreeImage dependecy.

2017-01-11 13:45:17 -04:00
parent ea7529f995
commit a9670e93f0
9 changed files with 154 additions and 33 deletions
--- a/whitted_tracer.cpp
+++ b/whitted_tracer.cpp
@@ -0,0 +1,92 @@
+#include <limits>
+
+#include <glm/gtc/constants.hpp>
+
+#include "whitted_tracer.hpp"
+
+using std::numeric_limits;
+using namespace glm;
+
+WhittedTracer::~WhittedTracer() { }
+
+vec3 WhittedTracer::trace_ray(Ray & r, vector<Figure *> & v_figures, vector<Light *> & v_lights, unsigned int rec_level) const {
+  float t, _t;
+  Figure * _f;
+  vec3 n, color, i_pos, ref, dir_diff_color, dir_spec_color;
+  Ray mv_r, sr, rr;
+  bool vis;
+  float kr;
+
+  t = numeric_limits<float>::max();
+  _f = NULL;
+
+  // Find the closest intersecting surface.
+  for (size_t f = 0; f < v_figures.size(); f++) {
+    if (v_figures[f]->intersect(r, _t) && _t < t) {
+      t = _t;
+      _f = v_figures[f];
+    }
+  }
+
+  // If this ray intersects something:
+  if (_f != NULL) {
+    // Take the intersection point and the normal of the surface at that point.
+    i_pos = r.m_origin + (t * r.m_direction);
+    n = _f->normal_at_int(r, t);
+    
+    // Check if the material is not reflective/refractive.
+    if( !_f->m_mat.m_refract) {
+      // Calculate the direct lighting.
+      for (size_t l = 0; l < v_lights.size(); l++) {
+	// For every light source
+	vis = true;
+
+	// Cast a shadow ray to determine visibility.
+	sr = Ray(v_lights[l]->direction(i_pos), i_pos + n * BIAS);
+	for (size_t f = 0; f < v_figures.size(); f++) {
+	  if (v_figures[f]->intersect(sr, _t) && _t < v_lights[l]->distance(i_pos)) {
+	    vis = false;
+	    break;
+	  }
+	}
+
+	// Evaluate the shading model accounting for visibility.
+	dir_diff_color += vis ? v_lights[l]->diffuse(n, r, t, _f->m_mat) : vec3(0.0f);
+	dir_spec_color += vis ? v_lights[l]->specular(n, r, t, _f->m_mat) : vec3(0.0f);
+      }
+      
+      color += (dir_diff_color * (_f->m_mat.m_diffuse / pi<float>())) + dir_spec_color;
+
+      // Determine the specular reflection color.
+      if (_f->m_mat.m_rho > 0.0f && rec_level < MAX_RECURSION) {
+	rr = Ray(normalize(reflect(r.m_direction, n)), i_pos + n * BIAS);
+	color += _f->m_mat.m_rho * trace_ray(rr, v_figures, v_lights, rec_level + 1);
+      } else if (_f->m_mat.m_rho > 0.0f && rec_level >= MAX_RECURSION)
+	  return vec3(0.0f);
+
+    } else {
+      // If the material has transmission enabled, calculate the Fresnel term.
+      kr = fresnel(r.m_direction, n, r.m_ref_index, _f->m_mat.m_ref_index);
+
+      // Determine the specular reflection color.
+      if (kr > 0.0f && rec_level < MAX_RECURSION) {
+	rr = Ray(normalize(reflect(r.m_direction, n)), i_pos + n * BIAS);
+	color += kr * trace_ray(rr, v_figures, v_lights, rec_level + 1);
+      } else if (rec_level >= MAX_RECURSION)
+	return vec3(0.0f);
+
+      // Determine the transmission color.
+      if (_f->m_mat.m_refract && kr < 1.0f && rec_level < MAX_RECURSION) {
+	rr = Ray(normalize(refract(r.m_direction, n, r.m_ref_index / _f->m_mat.m_ref_index)), i_pos - n * BIAS, _f->m_mat.m_ref_index);
+	color += (1.0f - kr) * trace_ray(rr, v_figures, v_lights, rec_level + 1);
+      } else if (rec_level >= MAX_RECURSION)
+	  return vec3(0.0f);
+
+    }
+
+    // Return final color.
+    return clamp(color, 0.0f, 1.0f);
+
+  } else
+    return BCKG_COLOR;
+}