/*
* Returns an array of colours representing the output image
*/
public Colour[,] GetImage(WorldSpace world, int width, int height, int reflectiveBounces = 4)
{
CalculateCorners();
for (int i = 0; i < world.objects.Count; i++)
{
world.objects[i].CalculateTriangles();
}
Colour[,] image = new Colour[width, height];
Vector3 deltaWidth = Vector3.Divide(Vector3.Subtract(transformedCorners[1], transformedCorners[0]), width);
Vector3 deltaHeight = Vector3.Divide(Vector3.Subtract(transformedCorners[2], transformedCorners[0]), height);
for (int i = 0; i < height; i++)
{
Vector3 heightPoint = Vector3.Add(transformedCorners[0], Vector3.Multiply(deltaHeight, i));
for (int j = 0; j < width; j++)
{
Vector3 point = Vector3.Add(heightPoint, Vector3.Multiply(deltaWidth, j));
Vector3 rayDir;
if (perspective)
{
rayDir = Vector3.Unit(Vector3.Subtract(point, origin));
}
else
{
rayDir = direction;
}
RayHit camHit = GetRayHitClipping(world, point, rayDir, near, far);
if (camHit.hit)
{
float smallestDistance = camHit.distances[0];
Vector3 closestIntersect = camHit.intersects[0];
Triangle triangle = camHit.triangles[0];
for (int k = 1; k < camHit.intersects.Count; k++)
{
if (camHit.distances[k] < smallestDistance)
{
smallestDistance = camHit.distances[k];
closestIntersect = camHit.intersects[k];
triangle = camHit.triangles[k];
}
}
image[j, i] = RayTrace(world, rayDir, closestIntersect, triangle, reflectiveBounces);
}
else
{
image[j, i] = background;
}
}
}
return(image);
}
/*
* Checks for intersections only if they are within a certain range of the camera
*/
public RayHit GetRayHitClipping(WorldSpace world, Vector3 start, Vector3 ray, float near, float far)
{
RayHit h = GetRayHit(world, start, ray, null);
RayHit newH = new RayHit();
for (int i = 0; i < h.intersects.Count; i++)
{
float perpDistance = h.distances[i];
if (perspective)
{
perpDistance *= Vector3.DotProduct(ray, direction);
}
if (perpDistance >= near - screenDistance && perpDistance <= far - screenDistance)
{
newH.hit = true;
newH.intersects.Add(h.intersects[i]);
newH.triangles.Add(h.triangles[i]);
newH.distances.Add(h.distances[i]);
}
}
return(newH);
}
/*
* Returns the colour that would be seen for a specific ray trace
*/
public Colour RayTrace(WorldSpace world, Vector3 viewVector, Vector3 intersect, Triangle triangle, int reflectiveBounces)
{
RayHit reflectHit;
Colour diffuse;
Vector3 lightRay;
float lightCos;
if (world.light.GetType() == typeof(DirectionalLight))
{
//Directional lighting
DirectionalLight worldLight = (DirectionalLight)world.light;
lightRay = Vector3.Unit(Vector3.Multiply(worldLight.lightVec, -1));
lightCos = Math.Abs(Vector3.DotProduct(lightRay, triangle.normal));
reflectHit = GetRayHit(world, intersect, lightRay, triangle);
diffuse = Colour.Combine(triangle.material.diffuse, world.light.colour, world.light.brightness * lightCos * triangle.material.diffuseVal);
}
else if (world.light.GetType() == typeof(SpotLight))
{
//Spot lighting
SpotLight worldLight = (SpotLight)world.light;
Vector3 spotVector = Vector3.Unit(Vector3.Multiply(worldLight.lightVec, -1));
lightRay = Vector3.Subtract(world.light.origin, intersect);
float lightDistance = lightRay.Magnitude();
lightRay = Vector3.Unit(lightRay);
lightCos = Math.Abs(Vector3.DotProduct(lightRay, triangle.normal));
if (Vector3.DotProduct(spotVector, lightRay) >= Math.Cos(worldLight.spotAngle))
{
reflectHit = GetRayHit(world, intersect, lightRay, triangle);
diffuse = Colour.Combine(triangle.material.diffuse, world.light.colour, world.light.brightness * lightCos * triangle.material.diffuseVal / (lightDistance * lightDistance));
}
else
{
reflectHit = new RayHit();
reflectHit.hit = true;
diffuse = new Colour(ColourList.BLACK);
}
}
else
{
//Point lighting
lightRay = Vector3.Subtract(world.light.origin, intersect);
float lightDistance = lightRay.Magnitude();
lightRay = Vector3.Unit(lightRay);
lightCos = Math.Abs(Vector3.DotProduct(lightRay, triangle.normal));
reflectHit = GetRayHit(world, intersect, lightRay, triangle);
diffuse = Colour.Combine(triangle.material.diffuse, world.light.colour, world.light.brightness * lightCos * triangle.material.diffuseVal / (lightDistance * lightDistance));
}
Colour ambient = Colour.Combine(triangle.material.diffuse, background, world.ambientBrightness);
Colour reflection = new Colour(ColourList.BLACK);
Colour specular = new Colour(ColourList.BLACK);
if (reflectiveBounces > 0 && triangle.material.reflectivity > 0)
{
//Checks for recursive reflectivity
Vector3 reverseVector = Vector3.Unit(Vector3.Multiply(viewVector, -1));
Vector3 reflectance = Vector3.Subtract(Vector3.Multiply(triangle.normal, 2 * Vector3.DotProduct(triangle.normal, reverseVector)), reverseVector);
Vector3 lightReflectance = Vector3.Subtract(Vector3.Multiply(triangle.normal, 2 * Vector3.DotProduct(triangle.normal, lightRay)), lightRay);
float specularDot = Vector3.DotProduct(lightReflectance, reverseVector);
if (specularDot < 0)
{
specularDot = 0;
}
specular = Colour.Combine(triangle.material.specular, world.light.colour, triangle.material.reflectivity * (float)Math.Pow(specularDot, triangle.material.shininess));
RayHit reflectionHit = GetRayHit(world, intersect, reflectance, triangle);
if (reflectionHit.hit)
{
float smallestDistance = reflectionHit.distances[0];
Vector3 reflectionIntersect = reflectionHit.intersects[0];
Triangle reflectionTriangle = reflectionHit.triangles[0];
for (int k = 1; k < reflectionHit.intersects.Count; k++)
{
if (reflectionHit.distances[k] < smallestDistance)
{
smallestDistance = reflectionHit.distances[k];
reflectionIntersect = reflectionHit.intersects[k];
reflectionTriangle = reflectionHit.triangles[k];
}
}
reflection = Colour.Add(reflection, Colour.Multiply(RayTrace(world, reflectance, reflectionIntersect, reflectionTriangle, reflectiveBounces - 1), triangle.material.reflectivity));
}
}
if (reflectHit.hit)
{
return(Colour.Add(ambient, reflection));
}
else
{
return(Colour.Add(ambient, diffuse, reflection, specular));
}
}
/*
* Checks to see if the current ray is intersecting a triangle
* This is where the most optimization is required
*/
public RayHit GetRayHit(WorldSpace world, Vector3 start, Vector3 ray, Triangle exclusionTriangle)
{
RayHit h = new RayHit();
for (int i = 0; i < world.objects.Count; i++)
{
//Checks to see if the ray is within an object's AABB
Vector3 minAABB = world.objects[i].minAABB;
Vector3 maxAABB = world.objects[i].maxAABB;
float tx1 = (minAABB.x - start.x) / ray.x;
float tx2 = (maxAABB.x - start.x) / ray.x;
float ty1 = (minAABB.y - start.y) / ray.y;
float ty2 = (maxAABB.y - start.y) / ray.y;
float tz1 = (minAABB.z - start.z) / ray.z;
float tz2 = (maxAABB.z - start.z) / ray.z;
float tmin, tmax;
if (tx1 < tx2)
{
tmin = tx1;
tmax = tx2;
}
else
{
tmin = tx2;
tmax = tx1;
}
float tmpmin, tmpmax;
if (ty1 < ty2)
{
tmpmin = ty1;
tmpmax = ty2;
}
else
{
tmpmin = ty2;
tmpmax = ty1;
}
if (tmax < tmpmin)
{
tmpmin = tmax;
}
if (tmin > tmpmax)
{
tmpmax = tmin;
}
if (tmin < tmpmin)
{
tmin = tmpmin;
}
if (tmax > tmpmax)
{
tmax = tmpmax;
}
if (tz1 < tz2)
{
tmpmin = tz1;
tmpmax = tz2;
}
else
{
tmpmin = tz2;
tmpmax = tz1;
}
if (tmax < tmpmin)
{
tmpmin = tmax;
}
if (tmin > tmpmax)
{
tmpmax = tmin;
}
if (tmin < tmpmin)
{
tmin = tmpmin;
}
if (tmax > tmpmax)
{
tmax = tmpmax;
}
if (tmax == tmin)
{
continue;
}
//Checks each triangle for intersection with vectors
for (int j = 0; j < world.objects[i].triangles.Length; j++)
{
Triangle currentTriangle = world.objects[i].triangles[j];
if (currentTriangle == exclusionTriangle)
{
continue;
}
if (Vector3.DotProduct(currentTriangle.normal, ray) >= 0)
{
continue;
}
float npb = Vector3.DotProduct(currentTriangle.normal, Vector3.Subtract(start, currentTriangle.vertices[1]));
float nr = Vector3.DotProduct(currentTriangle.normal, ray);
float t = 0; // distance
if (nr != 0)
{
t = -npb / nr;
}
if (t <= 0)
{
continue;
}
Vector3 ab = Vector3.Subtract(currentTriangle.vertices[0], currentTriangle.vertices[1]);
Vector3 cb = Vector3.Subtract(currentTriangle.vertices[2], currentTriangle.vertices[1]);
Vector3 ac = Vector3.Subtract(currentTriangle.vertices[0], currentTriangle.vertices[2]);
Vector3 intersect = Vector3.Add(start, Vector3.Multiply(ray, t));
Vector3 da = Vector3.Subtract(intersect, currentTriangle.vertices[0]);
Vector3 db = Vector3.Subtract(intersect, currentTriangle.vertices[1]);
Vector3 dc = Vector3.Subtract(intersect, currentTriangle.vertices[2]);
//Checks to see if there is a point of intersection
if (Vector3.DotProduct(currentTriangle.normal, Vector3.CrossProduct(da, ab)) >= 0 && Vector3.DotProduct(currentTriangle.normal, Vector3.CrossProduct(cb, db)) >= 0 && Vector3.DotProduct(currentTriangle.normal, Vector3.CrossProduct(ac, dc)) >= 0)
{
h.hit = true;
h.triangles.Add(currentTriangle);
h.intersects.Add(intersect);
h.distances.Add(t);
}
}
}
return(h);
}
static void Main(string[] args)
{
int width = 1280;
int height = 720;
string filename = "image";
Console.WriteLine("Importing models...\t 0% complete");
Importer importer = new Importer();
Console.WriteLine("Generating scene...\t25% complete");
Camera camera = new Camera(new Vector3(0, 3, 0), new Vector3(0, 0, -15), 80.0f, 1.0f, 40.0f, (float)height / width, true, new Colour(155, 230, 255));
WorldSpace world = new WorldSpace(0.15f);
Material orangeFlat = new Material(new Colour(ColourList.ORANGE), new Colour(ColourList.WHITE), 1.0f, 0.0f, 0);
Material greenShiny = new Material(new Colour(ColourList.YELLOW), new Colour(ColourList.WHITE), 1.0f, 0.5f, 5);
Material floorGrey = new Material(new Colour(ColourList.GREY), new Colour(ColourList.WHITE), 1.0f, 0.5f, 20);
Material glossPurple = new Material(new Colour(ColourList.PURPLE), new Colour(ColourList.WHITE), 1.0f, 0.9f, 3);
WorldObject pyramid = new WorldObject(
new Vector3(5, 1.5f, -1.5f),
new Vector3[] {
new Vector3(0, -1, 0),
new Vector3(1, 1, -1),
new Vector3(1, 1, 1),
new Vector3(-1, 1, 0)
},
new int[, ] {
{ 0, 1, 2 },
{ 0, 3, 1 },
{ 0, 2, 3 },
{ 3, 2, 1 }
},
new Material[] {
greenShiny,
orangeFlat,
greenShiny,
orangeFlat
}
);
WorldObject sphere = importer.ImportSTL(
new Vector3(6, 1.5f, 0),
glossPurple,
"sphere.stl"
);
WorldObject floor = new WorldObject(
new Vector3(0, 0, 0),
new Vector3[] {
new Vector3(0, 0, -20),
new Vector3(0, 0, 20),
new Vector3(40, 0, -20),
new Vector3(40, 0, 20),
new Vector3(0, -1, 0)
},
new int[, ] {
{ 0, 1, 2 },
{ 1, 3, 2 }
},
new Material[] {
floorGrey,
floorGrey
}
);
pyramid.RotateZ(45);
LightSource light = new PointLight(new Vector3(3.0f, 5.0f, 1.0f), 30.0f, new Colour(255, 247, 219));
//LightSource light = new SpotLight(new Vector3(3.0f, 5.0f, 1.0f), new Vector3(1, -1, 0), 60.0f, new Colour(36, 36, 36), 30.0f);
//LightSource light = new DirectionalLight(new Vector3(1, -1, -1), 0.7f, new Colour(255, 247, 219));
world.AddObject(pyramid);
world.AddObject(sphere);
world.AddObject(floor);
world.SetLight(light);
Exporter exporter = new Exporter(width, height);
Colour[,] image = new Colour[width, height];
Console.WriteLine("Rendering image...\t50% complete");
exporter.SetImage(camera.GetImage(world, width, height, 8));
Console.WriteLine("Exporting...\t\t75% complete");
exporter.CreateFile(filename);
Console.WriteLine("All jobs finished\t100% complete\n");
Console.WriteLine("Exported file " + filename + ".ppm");
Console.WriteLine("Press any key to continue");
Console.ReadLine();
}