public RayInfo(RayInfo vray) {
this.Org = vray.Org;
this.Dir = vray.Dir;
InvDir = 1f / vray.Dir;
this.MinT = vray.MinT;
this.MaxT = vray.MaxT;
}
public override Spectrum tau(RayInfo r, float stepSize, float offset) {
float t0, t1;
float length = r.Dir.Length;
if (length == 0f) return RgbSpectrum.ZeroSpectrum();
RayInfo rn = new RayInfo(r.Org, r.Dir / length, r.MinT * length, r.MaxT * length);
if (!IntersectP(rn, out t0, out t1)) return RgbSpectrum.ZeroSpectrum();
Spectrum tau = new RgbSpectrum();
t0 += offset * stepSize;
while (t0 < t1) {
var pt = rn.Point(t0);
var d = -rn.Dir;
tau += sigma_t(ref pt, ref d, 1.0f);
t0 += stepSize;
}
return tau * stepSize;
}
public RgbSpectrum SamplePhoton(SceneGeometryInfo scene, float u0, float u1, float u2, float u3, float u4, out float pdf, out RayInfo ray)
{
// Choose two points p1 and p2 on scene bounding sphere
var worldCenter = scene.BoundingSphereCenter;
var worldRadius = scene.BoundingSphereRadius * 1.01f;
var p1 = worldCenter + worldRadius * MC.UniformSampleSphere(u0, u1);
var p2 = worldCenter + worldRadius * MC.UniformSampleSphere(u2, u3);
// Construct ray between p1 and p2
ray = new RayInfo(p1, (p2 - p1).Normalize(), 1e-4f, 1e4f);
// Compute InfiniteAreaLight ray weight
Vector toCenter = (worldCenter - p1).Normalize();
var rayDir = ray.Dir;
float costheta = MathLab.AbsDot(ref toCenter, ref rayDir);
pdf = costheta / (4f * MathLab.M_PI * MathLab.M_PI * worldRadius * worldRadius);
return Le(ray.Dir);
}
public bool Intersect(ref RayInfo ray) {
return ShadowIntersectBVH(ref ray);
//return IntersectNode(RootNode, ray);
}
public bool Intersect(ref RayInfo ray, out RayHit intersection) {
intersection = new RayHit();
//return IntersectLBVH(ref ray, ref intersection);
return IntersectBVH(ref ray, ref intersection);
//return IntersectNode(RootNode, ray, out intersection);
}
private RgbSpectrum ShadeBackground(RayInfo ray)
{
if (EnvironmentMap == null)
{
return RgbSpectrum.ZeroSpectrum();
}
return EnvironmentMap.Le(-ray.Dir);
}
private void Intersect(ref RayInfo rayInfo, ref RayHit rayHit) {
//accel.Intersect(ref rayInfo, out rayHit);
}
public RgbSpectrum Sample(ref Point point, ref Normal n, float u0, float u1, float u2, out RayInfo ray, out float pdf)
{
var dir = (Position - point);
var l2 = dir.Length;
dir.Normalize();
pdf = MC.UniformSpherePdf();
ray = new RayInfo(point, dir, 1e-4f, l2 - 1e-4f);
return Power / l2;
}
public RgbSpectrum SamplePhoton(SceneGeometryInfo scene, float u0, float u1, float u2, float u3, float u4, out float pdf, out RayInfo ray)
{
Vector dir = MC.UniformSampleSphere(u0, u1);
ray = new RayInfo(Position+dir*Radius, dir, 1e-4f, 1e4f);
pdf = MathLab.INV4PI;
return (Power * Radius * MathLab.M_PI * 4f);
}
public RgbSpectrum Sample(ref Point point, ref Normal n, float u0, float u1, float u2, out RayInfo ray, out float pdf)
{
var samplePoint = new Point();
float b0, b1, b2;
int tries = 0;
int maxTries = 0;
startTry:
var tri = SampleTriangle();
tri.Sample(ref mesh.scene.Vertices, u2, u1, out samplePoint, out b0, out b1, out b2);
var TriangleNormal =NormalModifier * tri.ComputeNormal(ref mesh.scene.Vertices);
var area = tri.AreaV(ref mesh.scene.Vertices);
//var sampleN = TriangleNormal;
//var N = n;
Vector wi = samplePoint - point;
//wi.Normalize();
float distanceSquared = wi.Length2();
float distance = MathLab.Sqrt(distanceSquared);
wi /= distance;
var nw = -wi;
float sampleNdotMinusWi = Normal.Dot(ref TriangleNormal, ref nw);
float NdotWi = Normal.Dot(ref n, ref wi);
if ((sampleNdotMinusWi <= 0f) || (NdotWi <= 0f))
{
tries++;
if (tries > maxTries)
{
pdf = 0f;
ray = new RayInfo(Point.Zero, Vector.Zero);
return RgbSpectrum.ZeroSpectrum();
}
goto startTry;
}
ray = new RayInfo(point, wi, MathLab.RAY_EPSILON, distance - MathLab.RAY_EPSILON);
pdf = (distanceSquared / (sampleNdotMinusWi * meshArea)) * (1f / Math.Max(1, tries + 1));
// Using 0.01 instead of 0.0 to cut down fireflies
if (pdf <= 0.01f)
{
pdf = 0f;
return RgbSpectrum.ZeroSpectrum();
}
return gain * meshArea;
}
public abstract bool IntersectP(RayInfo ray, out float t0, out float t1);
public RayDifferential(RayInfo vray)
: base(vray)
{
hasDifferentials = false;
}
public RgbSpectrum SamplePhoton(SceneGeometryInfo scene, float u0, float u1, float u2, float u3, float u4, out float pdf,
out RayInfo ray)
{
float b0, b1, b2;
Point orig;
var tri = SampleTriangle(u4);
tri.Sample(ref mesh.scene.Vertices, u0, u1, out orig, out b0, out b1, out b2);
var TriangleNormal = NormalModifier * tri.ComputeNormal(ref mesh.scene.Vertices);
var area = tri.AreaV(ref mesh.scene.Vertices);
// Ray direction
var sampleN = TriangleNormal;
Vector dir = MC.UniformSampleSphere(u2, u3);
float RdotN = Normal.Dot(ref dir, ref sampleN);
if (RdotN < 0f)
{
dir *= -1f;
RdotN = -RdotN;
}
ray = new RayInfo(orig, dir);
pdf = (MathLab.INVTWOPI / area) * (1f / mesh.TrianglesCount);
return (gain * RdotN);
}
//Transform WorldToVolume;
public override bool IntersectP(RayInfo ray, out float t0, out float t1) {
return this.worldBound.Intersect(ray, out t0, out t1);
}
public void GetRay(double xp, double yp, out IRay cameraRay) {
var u = (float)(2.0f * xp / w - 1.0f);
var v = (float)(1.0f - 2.0f * yp / h);
Vector rdir = mRight * u + mUp * v + this.Look;
var rorig = (Position + rdir * 0.1f);
rdir.Normalize();
cameraRay = new RayInfo(rorig, rdir);
}
private RgbSpectrum Shade(MediumInfo currentMedium, float weight, RayInfo vray, IntersectionInfo isect, int depth)
{
var txtn = isect.GeometryInfo.GeoNormal;
var p = isect.GeometryInfo.HitPoint;
Vector v1, v2;
Vector.CoordinateSystem(ref txtn, out v1, out v2);
var Radiance = BaseColor * Vector.AbsDot(ref txtn, ref vray.Dir);
for (int i = 0; i < shadowRayCount; i++)
{
var dir = MC.CosineSampleHemisphere(rnd.Value.NextFloat(), rnd.Value.NextFloat());
dir = new Vector(v1.x * dir.x + v2.x * dir.y + txtn.x * dir.z, v1.y * dir.x + v2.y * dir.y + txtn.y * dir.z, v1.z * dir.x + v2.z * dir.y + txtn.z * dir.z);
stats.intersections++;
if (!manager.Intersect(new RayInfo(p, dir, 1e-4f, maxOcclussionRayLength)))
{
Radiance += AddedRadiance * (1.0f / shadowRayCount);
}
}
return Radiance;
}
private bool IntersectNode(Node node, ref RayInfo ray) {
if (node == null) {
return false;
}
float t1 = 0f, u = 0f, v = 0f;
if (IntersectBox(node.Bound, ref ray)) {
//ray.MinT = t0;
// ray.MaxT = t1;
if (node.nPrims > 0) {
for (var np = node.StartOffset; np < (node.StartOffset + node.nPrims); np++) {
if (Intersect(ref triangles[np], sceneVertices, ref ray, ref t1, ref u, ref v))
{
return true;
}
}
}
return IntersectNode(node.Left, ref ray) || IntersectNode(node.Right, ref ray);
}
return false;
}
protected PathVertex[] PropagatePath(RayInfo startRay, int maxPaths)
{
IntersectionInfo isect;
var vertices = new PathVertex[maxPaths];
var ray = new RayInfo(startRay);
var sm = rnd.Value;
for (int i = 0; i < maxPaths; i++)
{
Interlocked.Increment(ref stats.totalRays);
if (manager.Intersect(ray, out isect))
{
var vertice = new PathVertex { Wi = -ray.Dir };
Interlocked.Increment(ref stats.intersections);
var triangle = GetTriangle(isect.PrimitiveId, isect.PrimitiveIndex);
if (IsLight(triangle))
{
var lt = GetLight(triangle.Owner);
vertice.Emittance = lt.Le(ray.Dir);
vertices[i] = (vertice);
break;
}
vertice.Intersection = isect;
var bsdf = matLib.GetSurfMat(isect.Material.Name);
vertice.Bsdf = bsdf.First;
var t = RgbSpectrum.Unit;
vertice.BsdfSample = bsdf.Sample_f(ref vertice.Wi, out vertice.Wo, ref isect.GeometryInfo.GeoNormal,
ref isect.GeometryInfo.ShadingNormal, ref t,
sm.NextFloat(),
sm.NextFloat(),
sm.NextFloat(), ref isect.TextureData , out vertice.BsdfPdf,
out vertice.SpecularBounce);
vertices[i] = (vertice);
ray = new RayInfo(isect.GeometryInfo.HitPoint, vertice.Wo);
}
else
{
vertices[i] = (new PathVertex() { Wi = -ray.Dir });
break;
}
}
return vertices;
}
public abstract RgbSpectrum tau(RayInfo ray, float step = 1f, float offset = 0.5f);
public static RgbSpectrum EstimateDirect(ref Vector wo, IAccellerationStructure intersector, SceneGeometryInfo scene, ILight light, IntersectionInfo isect, SurfaceBsdf bsdf, FastRandom rnd)
{
RgbSpectrum Ld = new RgbSpectrum();
Vector wi;
float lightPdf, bsdfPdf;
RayInfo shadowRay;
RgbSpectrum Li = light.Sample(ref isect.GeometryInfo.HitPoint, ref isect.GeometryInfo.GeoNormal, rnd.NextFloat(), rnd.NextFloat(), rnd.NextFloat(),
out shadowRay, out lightPdf);
if (lightPdf > 0f && !Li.IsBlack())
{
wi = -shadowRay.Dir;
RgbSpectrum f ;
bsdf.f(ref wo, ref wi, ref isect.GeometryInfo.GeoNormal, ref Ld, out f);
if (!f.IsBlack() && !intersector.Intersect(shadowRay))
{
// Add light's contribution to reflected radiance
//Li *= visibility.Transmittance(scene, renderer, NULL, rng, arena);
if (light.IsDelta)
Ld += f * Li * (Vector.AbsDot(ref wi, ref isect.GeometryInfo.GeoNormal) / lightPdf);
else
{
bsdfPdf = bsdf.Pdf(ref wo, ref wi, BxDFTypes.BSDF_ALL_TYPES);
float weight = MC.PowerHeuristic(1, lightPdf, 1, bsdfPdf);
Ld += f * Li * (Vector.AbsDot(ref wi, ref isect.GeometryInfo.GeoNormal) * weight / lightPdf);
}
}
}
if (!light.IsDelta)
{
//float bsdfPdf;
bool spb;
BsdfSampleData result;
bsdf.Sample_f(ref wo, ref isect.GeometryInfo.GeoNormal, ref isect.GeometryInfo.ShadingNormal, ref Ld, rnd.NextFloat(),
rnd.NextFloat(), rnd.NextFloat(), ref isect.TextureData, out result);
bsdfPdf = result.Pdf;
if (!result.F.IsBlack() && result.Pdf > 0f)
{
if (lightPdf > 0f)
{
float weight = MC.PowerHeuristic(1, bsdfPdf, 1, lightPdf);
IntersectionInfo lightIsect;
RgbSpectrum li = new RgbSpectrum();
var ray = new RayInfo(isect.GeometryInfo.HitPoint, result.Wi, 1e-4f, 1e+4f);
if (intersector.Intersect(ray, out lightIsect))
{
if (light is TriangleLight && lightIsect.PrimitiveId.Equals(((TriangleLight)light).Owner.Id))
li = light.Le(-result.Wi);
}
else
li = light.Le(ray.Dir);
if (!li.IsBlack())
{
//Li *= scene->Transmittance(ray);
Ld += result.F * li * Vector.AbsDot(ref result.Wi, ref isect.GeometryInfo.GeoNormal) * weight / bsdfPdf;
}
}
}
}
/*
if (!light->IsDeltaLight()) {
BxDFType flags = BxDFType(BSDF_ALL & ~BSDF_SPECULAR);
Spectrum f = bsdf->Sample_f(wo, &wi,
bs1, bs2, bcs, &bsdfPdf, flags);
if (!f.Black() && bsdfPdf > 0.) {
lightPdf = light->Pdf(p, n, wi);
if (lightPdf > 0.) {
// Add light contribution from BSDF sampling
float weight = PowerHeuristic(1, bsdfPdf, 1, lightPdf);
Intersection lightIsect;
Spectrum Li(0.f);
RayDifferential ray(p, wi);
if (scene->Intersect(ray, &lightIsect)) {
if (lightIsect.primitive->GetAreaLight() == light)
Li = lightIsect.Le(-wi);
}
else
Li = light->Le(ray);
if (!Li.Black()) {
Li *= scene->Transmittance(ray);
Ld += f * Li * AbsDot(wi, n) * weight / bsdfPdf;
}
}
}
}
*/
return Ld;
}
public void GenerateRay(float xp, float yp, out RayInfo ray)
{
var u = 2.0f * xp / Width - 1.0f;
var v = 1.0f - 2.0f * yp / Height;
Vector rdir = x * u + y * v + dir;
var rorig = (Position + rdir * 0.1f);
rdir.Normalize();
ray = new RayInfo(rorig, -rdir);
}
public RgbSpectrum Sample(ref Point point, ref Normal n, float u0, float u1, float u2, out RayInfo ray, out float pdf)
{
var wi = MC.CosineSampleHemisphere(u1, u2);
pdf = wi.z * MathLab.INVPI;
Vector v1, v2;
Vector.CoordinateSystem(n.ToVec(), out v1, out v2);
wi = new Vector(
v1.x * wi.x + v2.x * wi.y + n.x * wi.z,
v1.y * wi.x + v2.y * wi.y + n.y * wi.z,
v1.z * wi.x + v2.z * wi.y + n.z * wi.z);
ray = new RayInfo(point, wi, 1e-4f, float.MaxValue);
return Le(wi);
}
public RgbSpectrum Sample(ref Point point, ref Normal n, float u0, float u1, float u2, out RayInfo ray, out float pdf)
{
var l = Position - point + MC.UniformSampleSphere(u0, u1) * Radius; // vector to random point on source
var Dist = l.Length; // distance to light source
var Attenuation = 17f / Dist; // distance attenuation of light
pdf = MC.UniformSpherePdf();
ray = new RayInfo(point, l / Dist, 1e-4f, Dist - 1e-4f);
return (Power*Radius / Dist);
}
public static bool IntersectBox(BBox box, RayInfo ray)
{
float t0 = ray.Min;
float t1 = ray.Max;
var rayInvDir = 1f / ray.Dir;
//1f /ray.Dir;
float invDirX = rayInvDir.x;
if (!process_box_coord(ref t0, ref t1, box.Min.x - ray.Org.x, box.Max.x - ray.Org.x, invDirX))
return false;
float invDirY = rayInvDir.y;
if (!process_box_coord(ref t0, ref t1, box.Min.y - ray.Org.y, box.Max.y - ray.Org.y, invDirY))
return false;
float invDirZ = rayInvDir.z;
if (!process_box_coord(ref t0, ref t1, box.Min.z - ray.Org.z, box.Max.z - ray.Org.z, invDirZ))
return false;
return true;
}
public bool IntersectLBVH(ref RayInfo ray, ref RayHit sp) {
int currentNode = 0;
float u = 0f, v = 0f, t1 = float.MaxValue, dist = float.MaxValue;
bool hit = false;
int stopNode = gpuBvhTree[0].SkipOffset;
sp.Index = RayBuffer.NotHit;
while (currentNode < stopNode) {
if (BBox.IntersectBox(ref gpuBvhTree[currentNode].Bound, ref ray)) {
if (gpuBvhTree[currentNode].PrimOffset != 0)
{
if (Intersect(ref triangles[gpuBvhTree[currentNode].PrimOffset], sceneVertices, ref ray, ref t1, ref u,
ref v)) {
var triangleIndex = gpuBvhTree[currentNode].PrimOffset;
dist = t1;
sp.Index = (uint)(triangleIndex);
sp.Distance = dist;
sp.U = u;
sp.V = v;
hit = true;
}
}
currentNode++;
}
else {
currentNode = gpuBvhTree[currentNode].SkipOffset;
}
}
return hit;
}
private RgbSpectrum Trace(RayInfo ray, float weight, MediumInfo currentMedium, int depth)
{
IntersectionInfo isect;
//RaysTraced++;
stats.totalRays++;
var color = new RgbSpectrum(0f);
if (manager.Intersect(ray, out isect))
{
stats.intersections++;
//Intersections++;
color = this.Shade(currentMedium, weight, ray, isect, depth);
}
else
{
color = this.ShadeBackground(ray);
}
return color;
}
public bool Intersect(ref Point[] meshVertices, ref RayInfo ray, ref float thit, ref float u, ref float v) {
Vector s1;
if (!edgesInitialized) {
Point.Sub(ref meshVertices[v1], ref meshVertices[v0], out e1);
Point.Sub(ref meshVertices[v2], ref meshVertices[v0], out e2);
edgesInitialized = true;
}
Vector.Cross(ref ray.Dir, ref e2, out s1);
var divisor = Vector.Dot(ref s1, ref e1);
if (divisor < MathLab.Epsilon)
return false;
var invDivisor = 1f / divisor;
Vector d, s2;
d = ray.Org - meshVertices[v0];
//Point.Sub(ref ray.Org, ref meshVertices[v0], out d);
var b1 = Vector.Dot(ref d, ref s1) * invDivisor;
if (b1 < 0f)
return false;
Vector.Cross(ref d, ref e1, out s2);
var b2 = Vector.Dot(ref ray.Dir, ref s2) * invDivisor;
if (b2 < 0f)
return false;
var b0 = 1f - b1 - b2;
if (b0 < 0f)
return false;
var t = Vector.Dot(ref e2, ref s2) * invDivisor;
if (t < ray.MinT || t > ray.MaxT)
return false;
thit = t;
u = b1;
v = b2;
return true;
}
private bool IntersectBVH(ref RayInfo ray, ref RayHit sp) {
if (bvhTree.Length == 0)
return false;
int triangleIndex = -1;
float u = 0f, v = 0f;
bool hit = false;
Vector invDir = ray.InvDirection;
//new Vector(1f / ray.Dir.x, 1f / ray.Dir.y, 1f / ray.Dir.z);
var dirIsNeg = new[] { invDir.x < 0, invDir.y < 0, invDir.z < 0 };
int todoOffset = 0, nodeNum = 0;
int[] todo = new int[TraversalStackSize];
var dist = float.MaxValue;
while (true) {
var node = bvhTree[nodeNum];
float t1 = 0f;
if (BBox.IntersectBox(ref node.Bound, ref ray)) {
//if (node.bbox.Intersect(vray, out t0, out t2)) {
if (node.PrimitiveCount > 0) {
for (var i = 0; i < node.PrimitiveCount; ++i) {
if (Intersect(ref triangles[node.PrimOffset + i], sceneVertices, ref ray, ref t1, ref u, ref v)) {
if (dist > t1) {
triangleIndex = node.PrimOffset + i;
dist = t1;
sp.Index = (uint)(triangleIndex);
sp.Distance = dist;
sp.U = u;
sp.V = v;
hit = true;
}
}
}
if (todoOffset == 0)
break;
nodeNum = todo[--todoOffset];
}
else {
if (dirIsNeg[node.Axis]) {
todo[todoOffset++] = nodeNum + 1;
nodeNum = node.SecondChildOffset;
}
else {
todo[todoOffset++] = node.SecondChildOffset;
nodeNum = nodeNum + 1;
}
}
}
else {
if (todoOffset == 0)
break;
nodeNum = todo[--todoOffset];
}
}
if (hit) {
return true;
}
sp.Index = RayBuffer.NotHit;
return false;
}
public static bool IntersectBox(AABB box, RayInfo ray)
{
float t0 = ray.minT;
float t1 = ray.maxT;
//float hitt0 = t0;
//float hitt1 = t1;
if (!process_box_coord(ref t0, ref t1, box.Min.x - ray.Org.x, box.Max.x - ray.Org.x, 1f / ray.Dir.x))
return false;
if (!process_box_coord(ref t0, ref t1, box.Min.y - ray.Org.y, box.Max.y - ray.Org.y, 1f / ray.Dir.y))
return false;
if (!process_box_coord(ref t0, ref t1, box.Min.z - ray.Org.z, box.Max.z - ray.Org.z, 1f / ray.Dir.z))
return false;
/*
for (int i = 0; i < 3; ++i) {
// Update interval for _i_th bounding box slab
float invRayDir = 1f / ray.Direction[i];
if (!process_box_coord(ref t0, ref t1, min[i] - ray.Origin[i], max[i] - ray.Origin[i], invRayDir)) return false;
}
* */
//ray.MinT = t0;
//ray.MaxT = t1;
//hitt0 = t0;
//hitt1 = t1;
return true;
}
private bool ShadowIntersectBVH(ref RayInfo ray) {
if (nodes.Count == 0)
return false;
bool hit = false;
Vector invDir = ray.InvDirection;
//new Vector(1f / ray.Dir.x, 1f / ray.Dir.y, 1f / ray.Dir.z);
var dirIsNeg = new[] { invDir.x < 0, invDir.y < 0, invDir.z < 0 };
int todoOffset = 0, nodeNum = 0;
int[] todo = new int[TraversalStackSize];
while (true) {
var node = bvhTree[nodeNum];
float t1 = 0f, u = 0f, v = 0f;
if (BBox.IntersectBox(ref node.Bound, ref ray)) {
if (node.PrimitiveCount > 0) {
for (var i = 0; i < node.PrimitiveCount; ++i) {
if (!Intersect(ref triangles[node.PrimOffset + i], sceneVertices, ref ray, ref t1, ref u, ref v))
continue;
hit = true;
break;
}
if (todoOffset == 0)
break;
nodeNum = todo[--todoOffset];
}
else {
if (dirIsNeg[node.Axis]) {
todo[todoOffset++] = nodeNum + 1;
nodeNum = node.SecondChildOffset;
}
else {
todo[todoOffset++] = node.SecondChildOffset;
nodeNum = nodeNum + 1;
}
}
}
else {
if (todoOffset == 0)
break;
nodeNum = todo[--todoOffset];
}
}
return hit;
}
