public ViewForm(string fileName)
{
InitializeComponent();
Manager = new SceneManager();
context = Manager.LoadScene(fileName, ctlCanvas.ClientRectangle.Width, ctlCanvas.ClientRectangle.Height);
this.imagePlane = context.Image;
iteration = 0;
rnd = new DotNetSampler();
ctlCanvas.Image = new Bitmap(ctlCanvas.ClientRectangle.Width, ctlCanvas.ClientRectangle.Height);
}
} // Camera
public void GetFrame(Scene scene, Sampler randomIn, Image image)
{
RayTracer rayTracer = new RayTracer(scene);
int width = image.Width;
int height = image.Height;
float halfAngle = (float)Math.Tan(viewAngle * 0.5f);
#if PARALLEL
Parallel.For(0, height, delegate(int y)
{
var random = randomIn.Clone();
#else
for (int y = 0; y < height; ++y)
{
Random random = randomIn;
#endif
for (int x = 0; x < width; ++x)
{
// make image plane displacement vector coefficients
float xF = (float)((x + random.GetNextSample()) * 2.0f / width) - 1.0f;
float yF = (float)((y + random.GetNextSample()) * 2.0f / height) - 1.0f;
// make image plane offset vector
Vector offset = (right * xF) + (up * yF * (height / width));
// make sample ray direction, stratified by pixels
Vector sampleDirection = (viewDirection + offset * halfAngle).Unitize();
// get radiance from RayTracer
Vector radiance = rayTracer.GetRadiance(ViewPosition, sampleDirection, random, null);
// add radiance to image
image.AddToPixel(x, y, radiance);
}
}
#if PARALLEL
);
#endif
}
}
Vector SampleEmitters(Vector rayDirection, SurfacePoint surfacePoint, Sampler random)
{
Vector radiance;
// single emitter sample, ideal diffuse BRDF:
// reflected = (emitivity * solidangle) * (emitterscount) *
// (cos(emitdirection) / pi * reflectivity)
// -- SurfacePoint does the first and last parts (in separate methods)
// get position on an emitter
Vector emitterPosition;
Triangle emitter;
scene.GetEmitter(random, out emitterPosition, out emitter);
// check an emitter was found
if (null != emitter)
{
// make direction to emit point
Vector emitDirection = (emitterPosition - surfacePoint.Position).Unitize();
// send shadow ray
Triangle hitObject;
Vector hitPosition;
scene.GetIntersection(surfacePoint.Position, emitDirection, surfacePoint.Item, out hitObject, out hitPosition);
StatsCounter.RayTraced();
// if unshadowed, get inward emission value
Vector emissionIn = null;
if ((null == hitObject) || (emitter == hitObject))
emissionIn = new SurfacePoint(emitter, emitterPosition).GetEmission(surfacePoint.Position, -emitDirection, true);
else
emissionIn = new Vector();
// get amount reflected by surface
radiance = surfacePoint.GetReflection(emitDirection, emissionIn * scene.GetEmittersCount(), -rayDirection);
}
else
radiance = new Vector();
return radiance;
}
public Vector GetRadiance(Vector rayOrigin, Vector rayDirection, Sampler random, Triangle lastHit)
{
// intersect ray with scene
Triangle pHitObject;
Vector hitPosition;
scene.GetIntersection(rayOrigin, rayDirection, lastHit, out pHitObject, out hitPosition);
Vector radiance;
if (null != pHitObject)
{
// make surface point of intersection
SurfacePoint surfacePoint = new SurfacePoint(pHitObject, hitPosition);
// local emission only for first-hit
if (lastHit != null)
radiance = Vector.ZERO;
else
radiance = surfacePoint.GetEmission(rayOrigin, -rayDirection, false);
// add emitter sample
radiance = radiance + SampleEmitters(rayDirection, surfacePoint, random);
// add recursive reflection
//
// single hemisphere sample, ideal diffuse BRDF:
// reflected = (inradiance * pi) * (cos(in) / pi * color) * reflectance
// -- reflectance magnitude is 'scaled' by the russian roulette, cos is
// importance sampled (both done by SurfacePoint), and the pi and 1/pi
// cancel out
Vector nextDirection;
Vector color;
// check surface bounces ray, recurse
if (surfacePoint.GetNextDirection(random, -rayDirection, out nextDirection, out color))
radiance = radiance + (color * GetRadiance(surfacePoint.Position, nextDirection, random, surfacePoint.Item));
}
else // no hit: default/background scene emission
radiance = scene.GetDefaultEmission(-rayDirection);
return radiance;
}
public Vector GetSamplePoint(Sampler random)
{
// get two randoms
float sqr1 = (float)Math.Sqrt(random.GetNextSample());
float r2 = (float)random.GetNextSample();
// make barycentric coords
float a = 1.0f - sqr1;
float b = (1.0f - r2) * sqr1;
// make position from barycentrics
// calculate interpolation by using two edges as axes scaled by the
// barycentrics
return edge1 * a + edge2 * b + verts[0];
}
public void GetEmitter(Sampler random, out Vector position, out Triangle triangle)
{
if (emitters.Count != 0)
{
// select emitter
// not using lower bits, by treating the random as fixed-point i.f bits
int index = ((((int)(int.MaxValue*random.GetNextSample()) & ((1 << MAX_EMITTERS_P) - 1)) * emitters.Count) >> MAX_EMITTERS_P);
// get position on triangle
position = emitters[index].GetSamplePoint(random);
triangle = emitters[index];
}
else
{
position = Vector.ZERO;
triangle = null;
}
}
