public RayTriangleIntersection IntersectionTest(Triangle triangle)
{
var result = new RayTriangleIntersection();
result.triangle = triangle;
result.ray = this;
var vx = triangle.RightCorner - this.origin;
var vy = triangle.LeftCorner - this.origin;
var vz = triangle.RootCorner - this.origin;
Matrix3 mat = Matrix3.FromColumnVectors(vx, vy, vz);
if (mat.Det == 0)//ray begin from triangle plane: no intersection
{
return(result);
}
Matrix3 matinv = mat.Inv;
Vector3 directive = matinv * direction;
//if(directive.MagnitudeSqr == 0) // impossible case
if (directive.X < 0 || directive.Y < 0 || directive.Z < 0)
{
return(result);
}
directive *= (1 / (directive.X + directive.Y + directive.Z));
result.HitPoint = mat * directive + this.origin;
result.distance = (result.HitPoint - this.origin).Magnitude;
result.IsIntersect = true;
return(result);
}
public RayTriangleIntersection IntersectionTest(Ray ray, List <Triangle> triangles)
{
RayTriangleIntersection firstIntersection = null;
foreach (var tri in triangles)
{
var intersection = ray.IntersectionTest(tri);
if (intersection.IsIntersect && intersection.distance > 0.000001)
{
if (firstIntersection == null || firstIntersection.distance > intersection.distance)
{
firstIntersection = intersection;
}
}
}
return(firstIntersection);
}
public Vector3 Trace(Ray ray, List <Triangle> triangles, int depth)
{
RayTriangleIntersection firstIntersection = IntersectionTest(ray, triangles);
Material mat = defaultMat;
//foreach (var tri in triangles)
//{
// var intersection = ray.IntersectionTest(tri);
// if (intersection.IsIntersect && intersection.distance > 0.000001)
// {
// if (firstIntersection == null || firstIntersection.distance > intersection.distance)
// {
// firstIntersection = intersection;
// }
// }
//}
if (firstIntersection != null)
{
if (firstIntersection.triangle.material != null)
{
mat = firstIntersection.triangle.material;
}
}
else
{
return(new ZeroVector3());
}
if (depth <= 0)
{
return(mat.Ambient(firstIntersection.triangle.PlaneNormal, -ray.direction));
}
Vector3 sum = Vector3.Zero;
//var randomDirections = RandomDirections.Get();
//int cnt = (int)Math.Pow(16, depth);
List <Vector3> dist = SphericalCode.DepthDestMap[depth];
var randMat = Matrix3.RandomRotate();
for (int ri = 0; ri < dist.Count; ri++)
{
//var dir = new Vector3(random.NextDouble() - 0.5, random.NextDouble() - 0.5, random.NextDouble() - 0.5);
//dir *= 0.2;
//dir += dist[ri];
var dir = randMat * dist[ri];
dir.Normalize();
var commingLight = Trace(new Ray(firstIntersection.HitPoint, dir), triangles, depth - 1);
foreach (var f in mat.lightDistributions)
{
var factor = f.GetFactor(firstIntersection.HitPoint, firstIntersection.triangle.PlaneNormal, -dir, -ray.direction);
var additionLight = new Vector3();
additionLight.X = commingLight.X * factor.X;
additionLight.Y = commingLight.Y * factor.Y;
additionLight.Z = commingLight.Z * factor.Z;
sum += additionLight;
}
}
sum *= 1.0 / dist.Count;
Vector3 result = sum + mat.Ambient(firstIntersection.triangle.PlaneNormal, -ray.direction);
return(result);
}
