Color TracePath(Ray ray, int depth)
{
if (depth >= MaxDepth)
{
return(Color.black); // Bounced enough times.
}
SceneRayHit hit = scene.RayCast(ray);
if (hit == null)
{
return(Color.black); // Nothing was hit.
}
Profiler.BeginSample("GetComponent<MeshRenderer");
Profiler.EndSample();
Profiler.BeginSample("GetEmissionColor");
var emittance = hit.HitObj.Emittance;
Profiler.EndSample();
// Pick a random direction from here and keep going.
// This is NOT a cosine-weighted distribution!
Profiler.BeginSample("RandomUnitVectorInHemisphere");
var direction = RandomUnitVectorInHemisphereOf(hit.normal);
Profiler.EndSample();
Ray newRay = new Ray(hit.point, direction);
// Recursively trace reflected light sources.
Color incoming = TracePath(newRay, depth + 1);
Profiler.BeginSample("LightCal");
// Probability of the newRay
float p = 1 / (2 * M_PI);
// Compute the BRDF for this ray (assuming Lambertian reflection)
Profiler.BeginSample("Dot");
float cos_theta = Mathf.Max(0, Vector3.Dot(newRay.direction.normalized, hit.normal.normalized));
Profiler.EndSample();
Profiler.BeginSample("GetColor");
Color BRDF = hit.HitObj.reflectance / M_PI;
Profiler.EndSample();
// Apply the Rendering Equation here.
var finalColor = emittance + (BRDF * incoming * cos_theta / p);
Profiler.EndSample();
return(finalColor);
}
public SceneRayHit RayCast(Ray ray)
{
SceneRayHit hitObj = new SceneRayHit();
for (int i = 0; i < SceneObjects.Length; ++i)
{
RaycastHit hit;
if (SceneObjects[i].RayCast(ray, out hit))
{
if (hitObj.HitObj == null || hit.distance < hitObj.distance)
{
hitObj.HitObj = SceneObjects[i];
hitObj.normal = hit.normal;
hitObj.point = hit.point;
hitObj.distance = hit.distance;
}
}
}
return(hitObj.HitObj != null ? hitObj : null);
}
