/// <summary>
/// Traces a ray and calculates the color using the methods implemented in raytracer implementations.
/// </summary>
/// <param name="ray">The ray that will be traced through the scene.</param>
/// <param name="recursionDepth">The current recursion depth. Optional, but should never be given at the first call.</param>
/// <returns>Returns the color that results when tracing the ray.</returns>
protected Color Trace(Ray ray, int recursionDepth = 0)
{
if (recursionDepth > Settings.RecursionDepth)
{
return(Color.Black);
}
// Intersect ray with scene objects and save to closestHit
if (!CurrentScene.Intersect(ray, out HitData closestHit))
{
return(calculateNoHitColor(ray));
}
Color color = Color.Black;
color += calculateDefaultColor(ray, closestHit);
// Check for each light if it is blocked by scene objects and calculate color contribution
CurrentScene.LightList.ForEach((ILight light) =>
{
//Offset start position the prevent casting of a shadow on itself.
Vector3 shadowRayDirection = light.Position - closestHit.Position;
shadowRayDirection.Normalize();
Vector3 offsettedStartPosition = closestHit.Position + Settings.SecondaryRayOffset * shadowRayDirection;
bool isOccluded = CurrentScene.Intersect(offsettedStartPosition, light.Position, out HitData shadowRayHit, true);
color += calculateColorPerLight(ray, closestHit, light, isOccluded);
});
// Handle reflective materials
if (closestHit.Material.Reflective(closestHit.TextureCoords) > 0.001f)
{
Vector3 reflectionDirection = ray.Direction.Reflect(closestHit.Normal);
Ray reflectionRay = new Ray(closestHit.Position + Settings.SecondaryRayOffset * reflectionDirection, reflectionDirection);
color += closestHit.Material.Reflective(closestHit.TextureCoords) * Trace(reflectionRay, recursionDepth + 1);
}
return(color);
}
