Start adding color modeling

Actors/Actor.cs

@@ -15,20 +15,42 @@ public virtual void StartRayRender(Point3D from, LightSource[] sources) {}
 
  public virtual (double DistranceProxy, int Id, Point3D Intersection) RenderRay(Point3D from, Point3D vector, double currentMinDistanceProxy) => default;
 
+ public virtual ColorProperties ColorAt(Point3D intersection, int id)
+ {
+ const int maxColor = 1 + (int)byte.MaxValue;
+ const int maxColorValue = maxColor * maxColor;
+
+ // emulate plastic
+ const double diffuse = 0.55;
+ const double factor = diffuse / (double)maxColor;
+
+ int value = id * maxColorValue / s_lastReserved;
+
+ double green = (double)(value / maxColor) * factor;
+ double blue = (double)(value % maxColor) * factor;
+
+ // Emulate plastic 
+ return new ColorProperties(
+ new Point3D(0.0, 0.0, 0.0),
+ new Point3D(x /*aka Red*/: diffuse, green, blue),
+ new Point3D(0.7, 0.7, 0.7),
+ 32);
+ }
+
  public virtual bool DoesItCastShadow(int sourceIndex, Point3D from, Point3D vector, int minId) => false;
 
  // Allows actors to reserve Ids, they will be granted a block count long starting at the returned value
  protected static int ReserveIds(int count)
  {
  lock (s_lockObject)
  {
- if (int.MaxValue - LastReserved <= count)
+ if (int.MaxValue - s_lastReserved <= count)
  {
- throw new OverflowException($"Reserved too many items! {nameof(LastReserved)}:{LastReserved} {nameof(count)}:{count}");
+ throw new OverflowException($"Reserved too many items! {nameof(s_lastReserved)}:{s_lastReserved} {nameof(count)}:{count}");
  }
 
- int result = LastReserved + 1;
- LastReserved = result + count;
+ int result = s_lastReserved + 1;
+ s_lastReserved = result + count;
  return result;
  }
  }
@@ -38,6 +60,6 @@ protected static int ReserveIds(int count)
 #endif
 
  private static readonly object s_lockObject = new object();
- public static int LastReserved {get; private set;} = default; // 0 is reserved for "none"
+ private static int s_lastReserved = default; // 0 is reserved for "none"
  }
 }

Actors/InfinitePlane.cs

@@ -1,15 +1,28 @@
+using System;
+
 namespace Ascii3dEngine
 {
  public class InfinitePlane : PolygonActorBase
  {
- public InfinitePlane(Settings settings, double? x = null, double? y = null, double? z = null) 
- : base(settings, GetData(x, y, z)) { }
+ public InfinitePlane(Settings settings, ColorProperties properties, double? x = null, double? y = null, double? z = null) 
+ : base(settings, GetData(x, y, z)) => m_properties = properties;
 
  // Don't Rotate
- public override void Act(System.TimeSpan timeDelta, System.TimeSpan elapsedRuntime, Camera camera) {}
+ public override void Act(System.TimeSpan timeDelta, System.TimeSpan elapsedRuntime, Camera camera) { }
+
+ public override ColorProperties ColorAt(Point3D intersection, int id) => m_properties; 
 
  private static (Point3D[] Points, int[][] Faces) GetData(double? x, double? y, double? z)
  {
+ int count = (x == null ? 0 : 1)
+ + (y == null ? 0 : 1)
+ + (z == null ? 0 : 1);
+
+ if (count != 1)
+ {
+ throw new ArgumentException($"Need to have one, and exactly one plane set, {x}, {y}, {z}");
+ }
+
  // ok so maybe they are not infinite
  double min = -Utilities.MaxRange;
  double max = Utilities.MaxRange;
@@ -38,10 +51,10 @@ private static (Point3D[] Points, int[][] Faces) GetData(double? x, double? y, d
  z ?? max),
  };
 
- System.Console.WriteLine(string.Join(System.Environment.NewLine, points));
-
  int[][] faces = new [] {new [] {0, 1, 2, 3}};
  return (points, faces);
  }
+
+ private readonly ColorProperties m_properties;
  }
 }

Engine/ColorProperties.cs

@@ -0,0 +1,84 @@
+using System.Runtime.CompilerServices;
+
+namespace Ascii3dEngine
+{
+ public readonly struct ColorProperties
+ {
+ [MethodImpl(MethodImplOptions.AggressiveInlining)]
+
+ public ColorProperties(Point3D ambient, Point3D diffuse, Point3D specular, double shininess)
+ {
+ Ambient = ambient;
+ Diffuse = diffuse;
+ Specular = specular;
+ Shininess = shininess;
+ }
+
+ public readonly Point3D Ambient;
+ public readonly Point3D Diffuse;
+ public readonly Point3D Specular;
+ public readonly double Shininess;
+
+ // From 423, but here are some more. https://www.barradeau.com/nicoptere/dump/materials.html
+ public static ColorProperties BlackPlastic = new ColorProperties(
+ new Point3D(0.0, 0.0, 0.0),
+ new Point3D(0.01, 0.01, 0.01),
+ new Point3D(0.5, 0.5, 0.5),
+ 32);
+
+ public static ColorProperties Brass = new ColorProperties(
+ new Point3D(0.329412, 0.223529, 0.027451),
+ new Point3D(0.780392, 0.568627, 0.113725),
+ new Point3D(0.992157, 0.941176, 0.807843),
+ 27.8974);
+
+ public static ColorProperties Bronze = new ColorProperties(
+ new Point3D(0.2125, 0.1275, 0.054),
+ new Point3D(0.714, 0.4284, 0.18144),
+ new Point3D(0.393548, 0.271906, 0.166721),
+ 25.6);
+
+ public static ColorProperties Chrome = new ColorProperties(
+ new Point3D(0.25, 0.25, 0.25),
+ new Point3D(0.4, 0.4, 0.4),
+ new Point3D(0.774597, 0.774597, 0.774597),
+ 76.8);
+
+ public static ColorProperties Copper = new ColorProperties(
+ new Point3D(0.19125, 0.0735, 0.0225),
+ new Point3D(0.7038, 0.27048, 0.828),
+ new Point3D(0.256777, 0.137622, 0.086014),
+ 12.8);
+
+ public static ColorProperties Gold = new ColorProperties(
+ new Point3D(0.24725, 0.1995, 0.0745),
+ new Point3D(0.75164, 0.60648, 0.22648),
+ new Point3D(0.628281, 0.555802, 0.366065),
+ 51.2);
+
+ public static ColorProperties Pewter = new ColorProperties(
+ new Point3D(0.10588, 0.058824, 0.113725),
+ new Point3D(0.427451, 0.470588, 0.541176),
+ new Point3D(0.3333, 0.3333, 0.521569),
+ 9.84615);
+
+ public static ColorProperties Silver = new ColorProperties(
+ new Point3D(0.19225, 0.19225, 0.19225),
+ new Point3D(0.50754, 0.50754, 0.50754),
+ new Point3D(0.508273, 0.508273, 0.508273),
+ 51.2);
+
+ public static ColorProperties PolishedSilver = new ColorProperties(
+ new Point3D(0.23125, 0.23125, 0.23125),
+ new Point3D(0.2775, 0.2775, 0.2775),
+ new Point3D(0.773911, 0.773911, 0.773911),
+ 89.6);
+
+ // https://www.sci.tamucc.edu/~sking/Courses/COSC5327/Assignments/Materials.html
+ public static ColorProperties WhitePlastic = new ColorProperties(
+ new Point3D(0.0, 0.0, 0.0),
+ new Point3D(0.55, 0.55, 0.55),
+ new Point3D(0.7, 0.7, 0.7),
+ 32);
+ }
+}

Engine/RayTracer.cs

@@ -105,9 +105,7 @@ public static string[] TraceCharRay(Settings settings, int width, int height, Sc
  double minDistanceProxy = double.MaxValue;
  int minId = default;
  Point3D minIntersection = default;
-#if (DEBUG)
  Actor minActor = default;
-#endif
 
  foreach (Actor actor in actors)
  {
@@ -117,9 +115,7 @@ public static string[] TraceCharRay(Settings settings, int width, int height, Sc
  minId = id;
  minDistanceProxy = distanceProxy;
  minIntersection = intersection;
-#if (DEBUG)
  minActor = actor;
-#endif
  }
  }
 
@@ -134,11 +130,19 @@ public static string[] TraceCharRay(Settings settings, int width, int height, Sc
  }
 #endif
 
- int value = minId * c_maxColorValue / Actor.LastReserved;
+ ColorProperties properties = minActor.ColorAt(minIntersection, minId);
 
- int red = byte.MaxValue;
- int green = value / c_maxColor;
- int blue = value % c_maxColor;
+ // just for testing lets assume all light intensity are 1.0
+
+ // See Page 761
+ double red = 1.0 * properties.Ambient.X;
+ double green = 1.0 * properties.Ambient.Y;
+ double blue = 1.0 * properties.Ambient.Z;
+
+ // we should compute Iambert = max(0, (s dot m) / (|s||m|))
+ red += (0.7 * properties.Diffuse.X);
+ green += (0.7 * properties.Diffuse.Y);
+ blue += (0.7 * properties.Diffuse.Z);
 
  for (int i = 0; i < sources.Length; i++)
  {
@@ -155,23 +159,25 @@ public static string[] TraceCharRay(Settings settings, int width, int height, Sc
  }
  }
 
- if (inShadow)
+ if (!inShadow)
  {
- red /= 2;
- green /= 2;
- blue /= 2;
+ // we should compute phong = max(0, (h dot m) / (|h||m|))
+ // Don't for get ^Shininess
+ red += (0.7 * properties.Specular.X);
+ green += (0.7 * properties.Specular.Y);
+ blue += (0.7 * properties.Specular.Z);
  }
  }
 
- result[x, y] = new Rgb24((byte)red, (byte)green, (byte)blue);
+ red = Math.Min(1.0, red);
+ green = Math.Min(1.0, green);
+ blue = Math.Min(1.0, blue);
+ result[x, y] = new Rgb24((byte)(red * 255.0), (byte)(green * 255.0), (byte)(blue * 255.0));
  }
  }
  });
 
  return result;
  }
-
- private const int c_maxColor = 1 + (int)byte.MaxValue;
- private const int c_maxColorValue = c_maxColor * c_maxColor;
  }
 }

Program.cs

@@ -91,7 +91,7 @@ private static int Run(Settings settings)
  scene.AddActor(new Model(settings));
  }
 
- scene.AddActor(new InfinitePlane(settings, y: -30.0));
+ scene.AddActor(new InfinitePlane(settings, ColorProperties.WhitePlastic, y: -30.0));
 
  scene.AddLightSource(new LightSource(
  new Point3D(0, 200, 0),

README.md

@@ -1 +1,2 @@
 ![Teapot with Shadow](docs/teapot_shadow.gif)
+![Teapot with Shadow](docs/teapot_color.gif)