/// <summary>
/// this is the main entrypoint for rendering a scene. this method is responsible for correctly rendering
/// the graphics device (in this case a bitmap).
/// Note that apart from the raytracing, painting on a graphics device is rather slow
/// </summary>
/// <param name="g">the graphics to render on</param>
/// <param name="viewport">basically determines the size of the bitmap to render on</param>
/// <param name="scene">the scene to render.</param>
public void RayTraceScene(Graphics g, Rectangle viewport, Scene scene)
{
int maxsamples = (int)AntiAliasing;
g.FillRectangle(Brushes.Black, viewport);
//Color[] scanline1;
//Color[] scanline2 = null;
//Color[] scanline3 = null;
Color[,] buffer = new Color[viewport.Width + 2, viewport.Height + 2];
for (int y = 0; y < viewport.Height + 2; y++)
{
DateTime timestart = DateTime.Now;
//// used for anti-aliasing
//scanline1 = scanline2;
//scanline2 = scanline3;
//scanline3 = new Color[viewport.Width + 2];
for (int x = 0; x < viewport.Width + 2; x++)
{
double yp = y * 1.0f / viewport.Height * 2 - 1;
double xp = x * 1.0f / viewport.Width * 2 - 1;
Ray ray = scene.Camera.GetRay(xp, yp);
// this will trigger the raytracing algorithm
buffer[x, y] = CalculateColor(ray, scene);
if ((x > 1) && (y > 1))
{
if (AntiAliasing != AntiAliasing.None)
{
Color avg = (buffer[x - 2, y - 2] + buffer[x - 1, y - 2] + buffer[x, y - 2] +
buffer[x - 2, y - 1] + buffer[x - 1, y - 1] + buffer[x, y - 1] +
buffer[x - 2, y] + buffer[x - 1, y] + buffer[x, y]) / 9;
if (AntiAliasing == AntiAliasing.Quick)
{
// this basically implements a simple mean filter
// it quick but not very accurate
buffer[x - 1, y - 1] = avg;
}
else
{ // use a more accurate antialasing method (MonteCarlo implementation)
// this will fire multiple rays per pixel
if (avg.Distance(buffer[x - 1, y - 1]) > 0.18) // 0.18 is a treshold for detailed aliasing
{
for (int i = 0; i < maxsamples; i++)
{
// get some 'random' samples
double rx = Math.Sign(i % 4 - 1.5) * (IntNoise(x + y * viewport.Width * maxsamples * 2 + i) + 1) / 4; // interval <-0.5, 0.5>
double ry = Math.Sign(i % 2 - 0.5) * (IntNoise(x + y * viewport.Width * maxsamples * 2 + 1 + i) + 1) / 4; // interval <-0.5, 0.5>
xp = (x - 1 + rx) * 1.0f / viewport.Width * 2 - 1;
yp = (y - 1 + ry) * 1.0f / viewport.Height * 2 - 1;
ray = scene.Camera.GetRay(xp, yp);
// execute even more ray traces, this makes detailed anti-aliasing expensive
buffer[x - 1, y - 1] += CalculateColor(ray, scene);
}
buffer[x - 1, y - 1] /= (maxsamples + 1);
}
}
}
// this is the slow part of the painting algorithm, it can be greatly speed up
// by directly accessing the bitmap data
Brush br = new SolidBrush(buffer[x - 1, y - 1].ToArgb());
g.FillRectangle(br, viewport.Left + x - 2, viewport.Top + y - 2, 1, 1);
br.Dispose();
}
}
// update progress after every scanline
if (RenderUpdate != null)
{
double progress = (y) / (double)(viewport.Height);
double duration = DateTime.Now.Subtract(timestart).TotalMilliseconds;
double ETA = duration / progress - duration;
RenderUpdate.Invoke((int)progress * 100, duration, ETA, y - 1);
}
}
}
public Tuple <Bitmap, int, RayTracer.RayTracer, int, DateTime> RayTraceRows(Scene scene, Rectangle viewport, int startRow, int numberOfRowsToTrace, RayTracer.RayTracer raytracer, int numberOfRange)
{
Console.SetCursorPosition(10, 2);
Console.Write(" ");
int maxsamples = (int)raytracer.AntiAliasing;
RayTracer.Color [ , ] buffer = new RayTracer.Color [viewport.Width + 2, numberOfRowsToTrace + 2];
DateTime timestart = DateTime.Now;
Bitmap image = new Bitmap(viewport.Width, numberOfRowsToTrace);
int y = 0;
for (y = startRow; y < (startRow + numberOfRowsToTrace) + 2; y++)
{
for (int x = 0; x < viewport.Width + 2; x++)
{
double yp = y * 1.0f / viewport.Height * 2 - 1;
double xp = x * 1.0f / viewport.Width * 2 - 1;
Ray ray = scene.Camera.GetRay(xp, yp);
// this will trigger the raytracing algorithm
buffer [x, y - startRow] = raytracer.CalculateColor(ray, scene);
// if current line is at least 2 lines into the scan
if ((x > 1) && (y > startRow + 1))
{
if (raytracer.AntiAliasing != AntiAliasing.None)
{
RayTracer.Color avg = (buffer [x - 2, y - startRow - 2] + buffer [x - 1, y - startRow - 2] + buffer [x, y - startRow - 2] +
buffer [x - 2, y - startRow - 1] + buffer [x - 1, y - startRow - 1] + buffer [x, y - startRow - 1] +
buffer [x - 2, y - startRow] + buffer [x - 1, y - startRow] + buffer [x, y - startRow]) / 9;
if (raytracer.AntiAliasing == AntiAliasing.Quick)
{
// this basically implements a simple mean filter
// it quick but not very accurate
buffer [x - 1, y - startRow - 1] = avg;
}
else
{ // use a more accurate antialasing method (MonteCarlo implementation)
// this will fire multiple rays per pixel
if (avg.Distance(buffer [x - 1, y - startRow - 1]) > 0.18) // 0.18 is a treshold for detailed aliasing
{
for (int i = 0; i < maxsamples; i++)
{
// get some 'random' samples
double rx = Math.Sign(i % 4 - 1.5) * (raytracer.IntNoise(x + y * viewport.Width * maxsamples * 2 + i) + 1) / 4; // interval <-0.5, 0.5>
double ry = Math.Sign(i % 2 - 0.5) * (raytracer.IntNoise(x + y * viewport.Width * maxsamples * 2 + 1 + i) + 1) / 4; // interval <-0.5, 0.5>
xp = (x - 1 + rx) * 1.0f / viewport.Width * 2 - 1;
yp = (y - 1 + ry) * 1.0f / viewport.Height * 2 - 1;
ray = scene.Camera.GetRay(xp, yp);
// execute even more ray traces, this makes detailed anti-aliasing expensive
buffer [x - 1, y - startRow - 1] += raytracer.CalculateColor(ray, scene);
}
buffer [x - 1, y - startRow - 1] /= (maxsamples + 1);
}
}
}
image.SetPixel(x - 2, y - startRow - 2, buffer [x - 1, y - startRow - 1].ToArgb());
}
}
//if ( ((y - startRow) / numberOfRowsToTrace * 100) % 10 == 0 )
//{
// Console.SetCursorPosition(10, 3);
// Console.Write(((y-startRow) / numberOfRowsToTrace * 100) + "% ");
//}
}
Console.SetCursorPosition(10, 3);
Console.Write(100 + "% ");
return(Tuple.Create <Bitmap, int, RayTracer.RayTracer, int, DateTime>(image, numberOfRange, raytracer, startRow, timestart));
}
public Bitmap RayTraceRows(Scene scene, Rectangle viewport, int startRow, int numberOfRowsToTrace)
{
int maxsamples = (int)AntiAliasing;
Color[,] buffer = new Color[viewport.Width + 2, numberOfRowsToTrace + 2];
Bitmap image = new Bitmap(viewport.Width, numberOfRowsToTrace);
for (int y = startRow; y < (startRow + numberOfRowsToTrace) + 2; y++)
{
for (int x = 0; x < viewport.Width + 2; x++)
{
double yp = y * 1.0f / viewport.Height * 2 - 1;
double xp = x * 1.0f / viewport.Width * 2 - 1;
Ray ray = scene.Camera.GetRay(xp, yp);
// this will trigger the raytracing algorithm
buffer[x, y - startRow] = CalculateColor(ray, scene);
// if current line is at least 2 lines into the scan
if ((x > 1) && (y > startRow + 1))
{
if (AntiAliasing != AntiAliasing.None)
{
Color avg = (buffer[x - 2, y - startRow - 2] + buffer[x - 1, y - startRow - 2] + buffer[x, y - startRow - 2] +
buffer[x - 2, y - startRow - 1] + buffer[x - 1, y - startRow - 1] + buffer[x, y - startRow - 1] +
buffer[x - 2, y - startRow] + buffer[x - 1, y - startRow] + buffer[x, y - startRow]) / 9;
if (AntiAliasing == AntiAliasing.Quick)
{
// this basically implements a simple mean filter
// it quick but not very accurate
buffer[x - 1, y - startRow - 1] = avg;
}
else
{ // use a more accurate antialasing method (MonteCarlo implementation)
// this will fire multiple rays per pixel
if (avg.Distance(buffer[x - 1, y - startRow - 1]) > 0.18) // 0.18 is a treshold for detailed aliasing
{
for (int i = 0; i < maxsamples; i++)
{
// get some 'random' samples
double rx = Math.Sign(i % 4 - 1.5) * (IntNoise(x + y * viewport.Width * maxsamples * 2 + i) + 1) / 4; // interval <-0.5, 0.5>
double ry = Math.Sign(i % 2 - 0.5) * (IntNoise(x + y * viewport.Width * maxsamples * 2 + 1 + i) + 1) / 4; // interval <-0.5, 0.5>
xp = (x - 1 + rx) * 1.0f / viewport.Width * 2 - 1;
yp = (y - 1 + ry) * 1.0f / viewport.Height * 2 - 1;
ray = scene.Camera.GetRay(xp, yp);
// execute even more ray traces, this makes detailed anti-aliasing expensive
buffer[x - 1, y - startRow - 1] += CalculateColor(ray, scene);
}
buffer[x - 1, y - startRow - 1] /= (maxsamples + 1);
}
}
}
image.SetPixel(x - 2, y - startRow - 2, buffer[x - 1, y - startRow - 1].ToArgb());
}
}
System.Windows.Forms.Application.DoEvents();
}
return(image);
}
