void tRender(int start, int end)
{
for (int i = start; i < end; i++)
{
for (int j = -_height / 2; j < _height / 2; j++)
{
Point3D p = _center + _direction * _distance + v1 * i / _zoom + v2 * j / _zoom;
Vector3D v = (Vector3D)p - (Vector3D)_center;
v /= v.Length;
Ray ray = new Ray(v, _center, 1, 1);
if (UpdateBitmap != null)
{
UpdateBitmap(renderer, i + _width / 2, j + _height / 2, ray.TraceRay(_space));
}
}
}
renderCounter++;
}
public Color TraceRay(Space3D space)
{
List <Intersection> intersections = new List <Intersection>();
foreach (Traceable t in space.objects)
{
if (t.FindIntersect(this) != null)
{
intersections.Add(t.FindIntersect(this));
}
}
int index = -1;
double distance = double.MaxValue;
for (int i = 0; i < intersections.Count; i++)
{
if (intersections[i].distance < distance && intersections[i].distance > 1)
{
distance = intersections[i].distance;
index = i;
}
}
double r = 0;
double g = 0;
double b = 0;
if (index > -1)
{
//if (traceDepth > 1)
//{
// System.Diagnostics.Trace.WriteLine("Hit after reflection!");
//}
Point3D intersectionPoint = origin + distance * vector;
//ambient
r += (double)space.ambient.R / 255 * (double)intersections[index].ambient.R / 255;
g += (double)space.ambient.G / 255 * (double)intersections[index].ambient.G / 255;
b += (double)space.ambient.B / 255 * (double)intersections[index].ambient.B / 255;
//lights
foreach (Light light in space.lights)
{
//diffuse
Color lightColor = light.getColor(intersectionPoint);
Vector3D lightDirection = light.getDirection(intersectionPoint);
Vector3D normal = intersections[index].normal;
lightDirection /= lightDirection.Length;
double dotProduct = Vector3D.DotProduct(lightDirection, normal);
if (dotProduct < 0)
{
r += ((double)intersections[index].ambient.R / 255) * ((double)lightColor.R / 255) * -dotProduct;
g += ((double)intersections[index].ambient.G / 255) * ((double)lightColor.G / 255) * -dotProduct;
b += ((double)intersections[index].ambient.B / 255) * ((double)lightColor.B / 255) * -dotProduct;
//specular
//refract
double refractConstRatio = refractConst / intersections[index].refractConst;
Vector3D refractDirection = refractConstRatio * lightDirection + (refractConstRatio * -dotProduct - Math.Sqrt(1 - Math.Pow(refractConstRatio, 2) * (1 - Math.Pow(dotProduct, 2)))) * normal;
refractDirection /= refractDirection.Length;
dotProduct = Vector3D.DotProduct(refractDirection, normal);
if (dotProduct > 0)
{
r += ((double)intersections[index].material.R / 255) * ((double)lightColor.R / 255) * Math.Pow(-dotProduct, intersections[index].specularConst);
g += ((double)intersections[index].material.G / 255) * ((double)lightColor.G / 255) * Math.Pow(-dotProduct, intersections[index].specularConst);
b += ((double)intersections[index].material.B / 255) * ((double)lightColor.B / 255) * Math.Pow(-dotProduct, intersections[index].specularConst);
}
//reflect
Vector3D lightReflect = lightDirection - 2 * dotProduct * normal;
lightReflect /= lightReflect.Length;
dotProduct = Vector3D.DotProduct(lightReflect, vector);
if (dotProduct < 0)
{
//System.Diagnostics.Trace.WriteLine("dotproduct = " + dotProduct);
r += ((double)intersections[index].specular.R / 255) * ((double)lightColor.R / 255) * Math.Pow(-dotProduct, intersections[index].specularConst);
g += ((double)intersections[index].specular.G / 255) * ((double)lightColor.G / 255) * Math.Pow(-dotProduct, intersections[index].specularConst);
b += ((double)intersections[index].specular.B / 255) * ((double)lightColor.B / 255) * Math.Pow(-dotProduct, intersections[index].specularConst);
}
}
}
//reflection
if (traceDepth < space.MaxDepth)
{
Vector3D normal = intersections[index].normal;
double dotProduct = Vector3D.DotProduct(vector, normal);
if (dotProduct < 0)
{
Ray reflectRay = new Ray(vector - 2 * dotProduct * normal, intersectionPoint, refractConst, traceDepth + 1);
Color reflectColor = reflectRay.TraceRay(space);
r += (double)reflectColor.R / 255;
g += (double)reflectColor.G / 255;
b += (double)reflectColor.B / 255;
}
}
//refraction
if (traceDepth < space.MaxDepth && intersections[index].refractConst != 0)
{
Vector3D normal = intersections[index].normal;
double dotProduct = Vector3D.DotProduct(vector, normal);
double refractConstRatio = refractConst / intersections[index].refractConst;
if (dotProduct < 0)
{
Vector3D refractDirection = refractConstRatio * vector + (refractConstRatio * -dotProduct - Math.Sqrt(1 - Math.Pow(refractConstRatio, 2) * (1 - Math.Pow(dotProduct, 2)))) * normal;
refractDirection /= refractDirection.Length;
dotProduct = Vector3D.DotProduct(refractDirection, normal);
if (dotProduct < 0)
{
Ray refractRay = new Ray(refractDirection, intersectionPoint, intersections[index].refractConst, traceDepth + 1);
Color refractColor = refractRay.TraceRay(space);
r += intersections[index].material.R / 255 * (double)refractColor.R / 255;
g += intersections[index].material.G / 255 * (double)refractColor.G / 255;
b += intersections[index].material.B / 255 * (double)refractColor.B / 255;
}
}
if (dotProduct > 0)
{
Vector3D refractDirection = refractConstRatio * vector + (refractConstRatio * dotProduct - Math.Sqrt(1 - Math.Pow(refractConstRatio, 2) * (1 - Math.Pow(dotProduct, 2)))) * normal;
refractDirection /= refractDirection.Length;
dotProduct = Vector3D.DotProduct(refractDirection, normal);
if (dotProduct > 0)
{
Ray refractRay = new Ray(refractDirection, intersectionPoint, 1, traceDepth + 1);
Color refractColor = refractRay.TraceRay(space);
r += (double)refractColor.R / 255;
g += (double)refractColor.G / 255;
b += (double)refractColor.B / 255;
}
}
}
}
if (r > 1)
{
r = 1;
}
r *= 255;
if (g > 1)
{
g = 1;
}
g *= 255;
if (b > 1)
{
b = 1;
}
b *= 255;
return(Color.FromArgb((int)r, (int)g, (int)b));
}