public Bitmap CreateBitmap()
{
Bitmap image = new Bitmap(this.width, this.height);
Random rand = new Random(0);
Photonmap photonmap = new Photonmap(this.intersectionFinder, this.data.LightSource, 100000);
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
int sampleCount = 10;
Vector sum = new Vector(0, 0, 0);
for (int i = 0; i < sampleCount; i++)
{
sum += EstimateColorWithPhotonmapping(x, y, rand, photonmap);
}
sum /= sampleCount;
image.SetPixel(x, y, VectorToColor(sum));
}
}
return(image);
}
private Vector EstimateColorWithPhotonmapping(int x, int y, Random rand, Photonmap photonmap)
{
Ray primaryRay = data.Camera.GetPrimaryRay(x, y);
float cosAtCamera = Vector.Dot(primaryRay.Direction, this.data.Camera.Forward);
Vector pathWeight = new Vector(1, 1, 1) * cosAtCamera;
var eyePoint = this.intersectionFinder.GetIntersectionPoint(primaryRay);
Vector pixelColor = new Vector(0, 0, 0);
if (eyePoint != null)
{
if (eyePoint.IsLocatedOnLightSource)
{
return(eyePoint.Emission);
}
pathWeight = Vector.Mult(pathWeight, DiffuseBrdf.Evaluate(eyePoint));
//Direct Lighting
var lightPoint = data.LightSource.GetRandomPointOnLightSource(rand);
if (IsVisible(eyePoint.Position, lightPoint.Position))
{
pixelColor += Vector.Mult(pathWeight, lightPoint.Color * GeometryTerm(eyePoint, lightPoint) / lightPoint.PdfA);
}
//Final Gathering
Vector newDirection = DiffuseBrdf.SampleDirection(eyePoint.Normal, rand);
pathWeight = pathWeight * Vector.Dot(eyePoint.Normal, newDirection) / DiffuseBrdf.PdfW(eyePoint.Normal, newDirection);
var finalGatherPoint = this.intersectionFinder.GetIntersectionPoint(new Ray(eyePoint.Position, newDirection));
if (finalGatherPoint != null)
{
//100000 3000 1000
float searchRadius = 0.00634257728f * 2;//0.0383904837f;//0.065260686f;
var photons = photonmap.SearchPhotons(finalGatherPoint, searchRadius);
float kernelFunction = 1.0f / (searchRadius * searchRadius * (float)Math.PI);
foreach (var photon in photons)
{
pixelColor += Vector.Mult(pathWeight, Vector.Mult(DiffuseBrdf.Evaluate(finalGatherPoint), photon.PathWeight) * kernelFunction);
}
}
}
return(pixelColor);
}
public Bitmap CreateBitmap()
{
Bitmap image = new Bitmap(this.width, this.height);
Random rand = new Random(0);
Photonmap photonmap = new Photonmap(this.intersectionFinder, this.data.LightSource, 100000);
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
Vector pixelColor = GetPixelColorFromPhotonmap(x, y, photonmap);
image.SetPixel(x, y, VectorToColor(pixelColor));
}
}
return(image);
}
private Vector GetPixelColorFromPhotonmap(int x, int y, Photonmap photonmap)
{
Ray primaryRay = data.Camera.GetPrimaryRay(x, y);
float cosAtCamera = Vector.Dot(primaryRay.Direction, this.data.Camera.Forward);
Vector pathWeight = new Vector(1, 1, 1) * cosAtCamera;
var eyePoint = this.intersectionFinder.GetIntersectionPoint(primaryRay);
Vector pixelColor = new Vector(0, 0, 0);
if (eyePoint != null)
{
//100000 3000 1000
float searchRadius = 0.00634257728f * 2;//0.0383904837f;//0.065260686f;
var photons = photonmap.SearchPhotons(eyePoint, searchRadius);
float kernelFunction = 1.0f / (searchRadius * searchRadius * (float)Math.PI);
foreach (var photon in photons)
{
pixelColor += Vector.Mult(pathWeight, Vector.Mult(DiffuseBrdf.Evaluate(eyePoint), photon.PathWeight) * kernelFunction);
}
}
return(pixelColor);
}
