/// <summary>
/// Get the color for the pixel
/// </summary>
/// <param name="intersection">The last point of intersection</param>
/// <param name="scene">The scene description</param>
/// <param name="depth">The current depth of recursion</param>
/// <returns>The color of the pixel</returns>
private Color Shade(Intersection intersection, Scene scene, int depth)
{
var direction = intersection.Ray.Direction;
var position = (intersection.Distance * intersection.Ray.Direction) + intersection.Ray.Start;
var normal = intersection.Element.Normal(position);
var reflectDir = direction - (2 * normal.Dot(direction) * normal);
var ret = Color.DefaultColor;
ret = ret + this.GetNaturalColor(intersection.Element, position, normal, reflectDir, scene);
if (depth >= MaxDepth)
{
return ret + new Color(.5, .5, .5);
}
return ret + this.GetReflectionColor(intersection.Element, position + 0.001 * reflectDir, normal, reflectDir, scene, depth);
}
/// <summary>
/// Get the color of an object at a point of intersection
/// </summary>
/// <param name="intersection">The last point of intersection</param>
/// <param name="scene">The scene description</param>
/// <param name="depth">The current depth of recursion</param>
/// <returns>The color of the pixel</returns>
private Color Shade(Intersection intersection, Scene scene, int depth)
{
// Use Fresnel's law to calculate the direction of the reflected light ray
// R = 2(N.L)*N - L
// R = reflection direction
// N = Normal at point of intersection
// L = -I
// I = direction of ray
var direction = -1 * intersection.Ray.Direction;
var position = (intersection.Distance * intersection.Ray.Direction) + intersection.Ray.Start;
var normal = intersection.Element.Normal(position);
var reflectDir = (2 * normal.Dot(direction) * normal) - direction;
var ret = Color.DefaultColor;
ret = ret + this.GetNaturalColor(intersection.Element, position, normal, reflectDir, scene);
if (depth >= MaxDepth)
{
return ret + new Color(.5, .5, .5);
}
// The color at this point is equal to the color of the object + any color reflecting on to it
return ret + this.GetReflectionColor(intersection.Element, position + 0.001 * reflectDir, normal, reflectDir, scene, depth);
}