public override bool getSample(RayContext rayContext, double ru, double rv, out Vector3 wi, out double invPdf)
{
Vector3 viewDir = rayContext.ray.dir;
Vector3 normal = rayContext.hitData.hitNormal;
Vector3 reflectDir = viewDir - (normal * (normal * viewDir) * 2.0);
reflectDir.normalize();
Matrix3 shadingMatrix = new Matrix3();
shadingMatrix.computeTangentBasis(reflectDir);
double pdf = 1;
invPdf = 1;
wi = MathUtils.getSpecularDir(ru, rv, glossy, out pdf);
wi = shadingMatrix.transformVector(wi);
wi.normalize();
if (pdf < 0.0001)
return false;
invPdf = 1.0 / pdf;
double cosT = rayContext.hitData.hitNormal * wi;
if (cosT < 0.0)
return false;
return true;
}
public bool trace(RayContext rayContext)
{
double maxt = rayContext.ray.maxt;
bool haveIntersection = false;
foreach (GeomPrimitive primitive in m_primitives)
{
if (rayContext.ignorePrimitive == primitive)
continue; //skip this primitive
IntersectionData hitData = new IntersectionData();
if (primitive.intersect(rayContext.ray, hitData))
{
if (maxt > hitData.hitT && hitData.hitT > rayContext.ray.mint)
{
maxt = hitData.hitT;
rayContext.hitData = hitData;
rayContext.hitData.hitPrimitive = primitive;
haveIntersection = true;
}
if (haveIntersection)
{
rayContext.hitData.hitPos = rayContext.ray.p + rayContext.ray.dir * rayContext.hitData.hitT;
}
}
}//foreach
return haveIntersection;
}
public Color3 getFilterColor(RayContext rayContext)
{
if (null != filterTexture)
return filterTexture.evalColor(rayContext);
return filterColor;
}
public virtual Color3 eval(RayContext rayContext, Vector3 wi, out double pdf)
{
pdf = 1.0;
if (null != filterTexture)
return filterTexture.evalColor(rayContext);
return filterColor;
}
public Color3 getTransparency(RayContext rayContext)
{
Color3 transparency = filterColor.getWhiteComplement();
if (null != filterTexture)
transparency = filterTexture.evalColor(rayContext).getWhiteComplement();
return transparency;
}
public override Color3 eval(RayContext rayContext, Vector3 wi, out double pdf)
{
pdf = System.Math.Max( rayContext.hitData.hitNormal * wi, 0.0) * (1.0 / System.Math.PI);
if (null != filterTexture)
return filterTexture.evalColor(rayContext);
return filterColor;
}
public static RayContext createNewContext(RayContext previousContext, Ray newRay)
{
RayContext newContext = new RayContext(newRay);
newContext.traceLevel += previousContext.traceLevel + 1;
newContext.scene = previousContext.scene;
newContext.ignorePrimitive = previousContext.hitData.hitPrimitive;
newContext.m_renderer = previousContext.m_renderer;
newContext.ignoreID = previousContext.ignoreID;
newContext.m_rndContext = previousContext.m_rndContext.createNew(previousContext.randomIndex, 2);
return newContext;
}
public override bool getSample(RayContext rayContext, double ru, double rv, out Vector3 wi, out double invPdf)
{
//в каква посока гледа наблюдателят (входящ лъч)
Vector3 viewDir = rayContext.ray.dir;
//faceforward се грижи нормалата винаги да е от страната на входящия лъч
Vector3 normal = MathUtils.faceforward(rayContext.hitData.hitNormal, viewDir);
//намираме посоката на отразения лъч (изходящ лъч)
wi = viewDir - (normal * (normal * viewDir) * 2.0);
wi.normalize();
invPdf = 0;
return true;
}
public override Color3 eval(RayContext rayContext, Vector3 wi, out double pdf)
{
Vector3 viewDir = rayContext.ray.dir;
Vector3 normal = rayContext.hitData.hitNormal;
Vector3 reflectDir = viewDir - (normal * (normal * viewDir) * 2.0);
reflectDir.normalize();
double cosA = wi * reflectDir;
double k = 0.0f;
if (cosA > 0.0f)
k = System.Math.Pow(cosA, glossy) * (glossy + 1.0f) * (2.0 / System.Math.PI);
pdf = k;
return filterColor *k;
}
public override bool getSample(RayContext rayContext, double ru, double rv, out Vector3 wi, out double invPdf)
{
Vector3 viewDir = rayContext.ray.dir;
Vector3 normal = rayContext.hitData.hitNormal;
double ior = 1.0 / m_ior;
double thetaView = viewDir * normal;
double thetaT = 1.0 - (ior * ior) * (1.0 - thetaView * thetaView);
wi = new Vector3(0, 0, 0);
invPdf = 0;
if (thetaT < 0.0f) // проверка за пълно вътрешно отражение
return false;
wi = ior * viewDir - (ior * thetaView + System.Math.Sqrt(thetaT)) * normal;
invPdf = 0;
return true;
}
public Color3 getRadiance(RayContext rayContext)
{
Vector3 d = new Vector3();
d.set( rayContext.ray.dir );
double len = System.Math.Sqrt(d.x*d.x + d.y*d.y);
double r = (len<0.0001) ? 0.0f : System.Math.Acos(-d.z)/(2.0f*System.Math.PI*len);
double u = r*d.x + 0.5f;
double v = 0.5f - r*d.y;
int w = m_skyTexture.getWidth(), h = m_skyTexture.getHeight();
double x = System.Math.Min(System.Math.Max(u, 0), 1);
double y = System.Math.Min(System.Math.Max(v, 0), 1);
Color3 c = new Color3();//m_skyTexture.evalColor(x, y);
//System.Diagnostics.Debug.WriteLine(x.ToString()+" "+y.ToString());
return c;
}
public override LightSample getSample(RayContext rayContext, double ru, double rv)
{
//намираме векрор между двете точки
Vector3 dir = pos - rayContext.hitData.hitPos;
//определяме каква част от сферата (пространствен ъгъл) покрива точката
double solidAngle = (1.0 / (4.0 * System.Math.PI * dir.getLenghtSqr()));
//максимална дистанция за търсене на пресичания
double maxt = dir.getLenght(); dir.normalize();
//ако светлината се намира под повърхността от която е точката,
//няма смисъл да пресмятаме нищо
if (dir * (rayContext.hitData.hitNormal) <= 0)
return null;
//създаваме "сонда за сянка" и попълваме
LightSample sample = new LightSample();
sample.shadowRay = new Ray();
sample.shadowRay.p.set(rayContext.hitData.hitPos);
sample.shadowRay.dir.set(dir);
sample.shadowRay.maxt = maxt;
//задаваме енергията (изпратена през пространствения ъгъл)
sample.color = color * (power * solidAngle);
return sample;
}
public Color3 illuminate(RayContext rayContext, BRDF brdf)
{
Color3 finalColor = new Color3();
BRDFTypes brdfType = brdf.getType();
if (brdf.matchTypes(BRDFTypes.Diffuse) || brdf.matchTypes(BRDFTypes.Glossy))
{
if (null != m_directLightIntegrator)
finalColor += m_directLightIntegrator.illuminate(rayContext, brdf);
if (brdf.matchTypes(BRDFTypes.Diffuse) && null != m_diffuseIntegrator)
finalColor += m_diffuseIntegrator.illuminate(rayContext, brdf);
}
if (brdf.matchTypes(BRDFTypes.Specular))
{
if (rayContext.traceLevel < m_maxTraceLevel)
if (null != m_specularIntegrator)
finalColor += m_specularIntegrator.illuminate(rayContext, brdf);
}
return finalColor;
}
public Color3 evalColor(RayContext rayContext)
{
return evalColorBilinear(rayContext.hitData.textureUVW.x, rayContext.hitData.textureUVW.y);
}
public override void shade(RayContext rayContext)
{
rayContext.resultColor = texture.evalColor(rayContext);
}
public abstract void shade(RayContext rayContext);
//return True if the sample ray is valid and False otherwise public abstract bool getSample(RayContext rayContext, double ru, double rv, out Vector3 wi, out double invPdf);
public static RayContext startFromPixel(Ray startRay, int pixX, int pixY, Scene _scene, IIntegrator integrator)
{
RayContext newContext = new RayContext(startRay);
newContext.scene = _scene;
newContext.m_renderer = integrator;
newContext.m_rndContext = new RandomContext(2, 17 * pixX + 73 * pixY);
return newContext;
}
public Color3 shadeBackground(RayContext rayContext)
{
if (null != m_skyDome)
return m_skyDome.getRadiance(rayContext);
return backgroundColor;
}
public bool trace(RayContext rayContext)
{
return m_bruteforceTracer.trace( rayContext );
}
public static RayContext createNewContextGI(RayContext previousContext, Ray newRay)
{
RayContext newContext = createNewContext(previousContext, newRay);
newContext.traceLevelGI += previousContext.traceLevelGI + 1;
return newContext;
}
public void shade(RayContext rayContext)
{
if( trace(rayContext) ) {
if( null != rayContext.hitData.hitPrimitive ) {
rayContext.hitData.hitPrimitive.shader.shade(rayContext);
return;
}
}
rayContext.resultColor.set( shadeBackground(rayContext) );
}
public bool traceShadowRay(Ray shadowRay, RayContext origContext)
{
RayContext rayContext = RayContext.createNewContext(origContext, shadowRay);
rayContext.ignorePrimitive = origContext.hitData.hitPrimitive;
rayContext.isShadowRay = true;
return trace(rayContext);
}
public bool trace(RayContext rayContext)
{
GeomPrimitive hitObject;
rayContext.hitData = null;
GetIntersection(rayContext.ray.p, rayContext.ray.dir, rayContext.ignorePrimitive, out hitObject, rayContext.ray.p, rayContext);
if (rayContext.hitData == null)
return false;
return rayContext.hitData.hasIntersection ;
}
public void GetIntersection(
Vector3 rayOrigin, Vector3 rayDirection, GeomPrimitive lastHit,
out GeomPrimitive pHitObject, Vector3 pStart, RayContext rayContext)
{
//hitPosition = null;
pHitObject = null;
// is branch: step through subcells and recurse
if (isBranch)
{
//if (pStart == null)
// pStart = rayOrigin;
// find which subcell holds ray origin (ray origin is inside cell)
int subCell = 0;
for (int i = 3; i-- > 0; )
{
// compare dimension with center
if (pStart[i] >= ((bound[i] + bound[i + 3]) * 0.5f))
subCell |= 1 << i;
}
// step through intersected subcells
Vector3 cellPosition = new Vector3(pStart);
for (; ; )
{
if (null != spatial[subCell])
{
// intersect subcell
spatial[subCell].GetIntersection(rayOrigin, rayDirection, lastHit, out pHitObject, cellPosition, rayContext);
// exit if item hit
if (null != pHitObject)
break;
}
// find next subcell ray moves to
// (by finding which face of the corner ahead is crossed first)
int axis = 2;
float[] step = new float[3]; // todo - move this allocation?
for (int i = 3; i-- > 0; axis = step[i] < step[axis] ? i : axis)
{
bool high = ((subCell >> i) & 1) != 0;
float face = (rayDirection[i] < 0.0f) ^ high ? bound[i + ((high ? 1 : 0) * 3)] : (bound[i] + bound[i + 3]) * 0.5f;
// distance to face
// (div by zero produces infinity, which is later discarded)
step[i] = (float)(face - rayOrigin[i]) / (float)rayDirection[i];
}
// leaving branch if: subcell is low and direction is negative,
// or subcell is high and direction is positive
if ((((subCell >> axis) & 1) != 0) ^ (rayDirection[axis] < 0.0f))
break;
// move to (outer face of) next subcell
cellPosition = rayOrigin + (rayDirection * step[axis]);
subCell = subCell ^ (1 << axis);
}
}
else
{ // is leaf: exhaustively intersect contained items
//float nearestDistance = float.MaxValue;
// step through items
foreach (GeomPrimitive item in triangles)
{
if (rayContext.ignorePrimitive == item)
continue; //skip this primitive
if (item == lastHit)
continue; //skip this primitive
IntersectionData hitData = new IntersectionData();
if (item.intersect(rayContext.ray, hitData))
{
// check intersection is inside cell bound (with tolerance)
Vector3 hit = rayOrigin + (rayDirection * hitData.hitT);
float t = TOLERANCE;
if ((bound[0] - hit[0] <= t) && (hit[0] - bound[3] <= t) &&
(bound[1] - hit[1] <= t) && (hit[1] - bound[4] <= t) &&
(bound[2] - hit[2] <= t) && (hit[2] - bound[5] <= t))
{
pHitObject = item;
//nearestDistance = distance;
//hitPosition = hit;
rayContext.hitData = hitData;
rayContext.hitData.hitPrimitive = item;
rayContext.hitData.hitPos = rayContext.ray.p + rayContext.ray.dir * rayContext.hitData.hitT;
rayContext.hitData.hasIntersection = true;
}
}
}
}
}
public Color3 illuminate(RayContext rayContext, BRDF brdf)
{
return new Color3();
}
public Color3 illuminate(RayContext rayContext, BRDF brdf)
{
//вземаме списък с всички светлини в сцената
List<Light> lights = rayContext.scene.getLights();
//в sumColor ще сумираме тяхната енергия
Color3 sumColor = new Color3();
foreach (Light light in lights)
{
Color3 color = new Color3();
//задаваме максималната бройка лъчи
//с които ще проследяваме към всяка светлина
int numSamples = 25;
int curSample = 0; //номер на текущ лъч
LightSample lightSample;
rayContext.randomIndex = 0;
do
{
curSample++;
//генерирме двойка случайни числа (ru, rv)
double ru = rayContext.getRandom(0, curSample);
double rv = rayContext.getRandom(1, curSample);
//искаме от светлината да върне сонда за сянка
lightSample = light.getSample(rayContext, ru, rv);
rayContext.randomIndex++;
if (null == lightSample)
continue;
//пресмятаме косинуса между нормалата на повърхността и лъча към лампата
double cosT = rayContext.hitData.hitNormal * (lightSample.shadowRay.dir);
if (cosT < 0.00001) cosT = 0.0;
//проверяваме за засенчване
if (rayContext.scene.traceShadowRay(lightSample.shadowRay, rayContext))
continue;
double pdf = 1.0;
//пресмятаме, каква част от светлината ще отрази BRFD-a
Color3 brdfCol = brdf.eval(rayContext, lightSample.shadowRay.dir, out pdf);
color += brdfCol * pdf * lightSample.color * cosT;
//ако светлината е точкова ни е нужен само един лъч
if (light.isSingular())
break;
} while (curSample < numSamples);
if (curSample < 1)
curSample = 1;
//сумираме резултата от всички сампъли
color *= 1.0 / (double)curSample;
sumColor += color;
}
int lightsCount = lights.Count;
if (lightsCount < 1)
lightsCount = 1;
//сумираме енергията от всички светлини
sumColor *= 1.0 / (double)lightsCount;
return sumColor;
}
public abstract LightSample getSample(RayContext rayContext, double ru, double rv);
public override void shade(RayContext rayContext)
{
rayContext.resultColor = color;
}
public Color3 illuminate(RayContext rayContext, BRDF brdf)
{
Ray newRay = new Ray();
double invPdf = 0;
//във finalColor ще сумираме резултатния цвят
Color3 finalColor = new Color3();
//задаваме максималната бройка лъчи
//с които ще проследяваме грапави отражения
int numSamples = 10;
int curSample = 0; //номер на текущ лъч
for (curSample = 0; curSample < numSamples; curSample++)
{
//генерирме двойка случайни числа (ru, rv)
double ru = rayContext.getRandom(0, curSample);
double rv = rayContext.getRandom(1, curSample);
//искаме brdf да конструира лъч използвайки (ru, rv)
bool isValidSample = brdf.getSample(rayContext, ru, rv, out newRay.dir, out invPdf);
if (!isValidSample)
continue;
//конструираме нов лъч от текущата точка
//и го обвиваме във собствен контекст
newRay.p = rayContext.hitData.hitPos;
RayContext newContext = RayContext.createNewContext(rayContext, newRay);
//извикваме функцията shade, която проследява
//лъча в сцената и го осветява
rayContext.scene.shade(newContext);
double cosT = rayContext.hitData.hitNormal * (newRay.dir);
if (cosT < 0.0) cosT *= -1.0;
double pdf;
Color3 w = new Color3(1, 1, 1);
//пресмятаме, каква част от светлината ще отрази BRFD-a
w = brdf.eval(rayContext, newRay.dir, out pdf);
if (!brdf.isSingular())
{
w *= cosT * invPdf;
}
//добавяме енергията на новия лъч
finalColor += newContext.resultColor * w;
//if (Double.IsNaN(finalColor.getIntensity()))
// break;
if (brdf.isSingular())
break;
}
//сумираме енергията от всички лъчи
if (curSample > 0)
finalColor *= 1.0 / (double)curSample;
return finalColor;
}
