public override bool IsHit(Ray ray, HitRecord record, float near, float far)
{
throw new NotImplementedException();
}
public override bool IsHit(Ray ray, HitRecord record, float near, float far)
{
Vector newCenter;
if (Velocity.IsBlack())
newCenter = Center;
else
{
newCenter = this.Center + ray.Time * this.Velocity;
}
//e - c
Vector eMinusC = ray.Start - newCenter;
//d.(e-c)
float dDotEMinusC = Vector.Dot3(ray.Direction, eMinusC);
float dDotD = Vector.Dot3(ray.Direction, ray.Direction);
//d.(e-c)^2 - (d.d)((e-c).(e-c) - R^2))
float discriminant = dDotEMinusC * dDotEMinusC - dDotD * (Vector.Dot3(eMinusC, eMinusC) - this.Radius * this.Radius);
//Intersection occurs
float t1 = 0, t2 = 0, first_t = 0;
if (discriminant >= 0)
{
t1 = (-dDotEMinusC + (float)Math.Sqrt(discriminant)) / dDotD;
t2 = (-dDotEMinusC - (float)Math.Sqrt(discriminant)) / dDotD;
Vector diff;
Vector worldCoords;
if (t2 >= 0)
first_t = t2;
else if (t1 >= 0)
first_t = t1;
else
return false;
// t*d
diff = ray.Direction * first_t;
// e + t*d
worldCoords = diff + ray.Start;
float distance = diff.Magnitude3();
if (distance <= record.Distance && distance <= ray.MaximumTravelDistance)
{
if (ray.UseBounds)
{
float cameraOrthogonalDistance = Math.Abs(Vector.Dot3(diff, ray.CameraLookDirection));
if (cameraOrthogonalDistance > far && cameraOrthogonalDistance < near)
{
return false;
}
}
record.T = first_t;
record.HitPoint = ray.Start + diff;
record.Distance = distance;
record.Material = this.Material;
record.SurfaceNormal = SurfaceNormal(record.HitPoint, ray.Direction);
if (Material.TextureImage != null)
{
double cos = (record.HitPoint.z - newCenter.z) / Radius;
if (cos < -1)
cos = -1;
else if (cos > 1)
cos = 1;
double theta = Math.Acos(cos);
double phi = Math.Atan2(record.HitPoint.y - newCenter.y, record.HitPoint.x - newCenter.x);
if (phi < 0)
phi += 2 * Math.PI;
float u = (float)(phi / (2 * Math.PI));
float v = (float)((Math.PI - theta) / Math.PI);
//Console.WriteLine(this.textureWidth);
//Console.WriteLine(this.Material.TextureImage.Height);
//int i = (int)(u * (this.textureWidth - 1) + 0.5);
//int j = (int)(v * (this.textureHeight - 1) + 0.5);
record.TextureColor = this.Material.GetTexturePixelColor(u, v);
}
return true;
}
}
return false;
}
public override bool IsHit(Ray ray, HitRecord record, float near, float far)
{
//(d.h)h
Vector dDotHTimesH = Vector.Dot3(ray.Direction, HeightDirection) * HeightDirection;
Vector deltaP = ray.Start - this.BasePoint;
Vector deltaPDotHTimesH = Vector.Dot3(deltaP, HeightDirection) * HeightDirection;
Vector deltaPMinusdeltaPDotHTimesH = deltaP - deltaPDotHTimesH;
Vector dMinusdDotHTimesH = ray.Direction - dDotHTimesH;
float B = 2 * Vector.Dot3(dMinusdDotHTimesH, deltaPMinusdeltaPDotHTimesH);
float A = Vector.Dot3(dMinusdDotHTimesH, dMinusdDotHTimesH);
float C = Vector.Dot3(deltaPMinusdeltaPDotHTimesH, deltaPMinusdeltaPDotHTimesH) - this.Radius * this.Radius;
Vector diff, worldCoords;
float discriminant = B * B - 4 * A * C;
float t1 = 0, t2 = 0, first_t = float.MaxValue;
List<float> candidates = new List<float>();
IntersectionType intersectionType = IntersectionType.Cylinder;
if (discriminant >= 0)
{
t1 = (-B - (float)Math.Sqrt(discriminant)) / (2 * A);
t2 = (-B + (float)Math.Sqrt(discriminant)) / (2 * A);
if (t1 >= 0 && IsInside(ray.Start + ray.Direction*t1))
{
first_t = t1;
}
if (t2 >= 0 && IsInside(ray.Start + ray.Direction*t2) && t2 < first_t)
{
first_t = t2;
}
}
float hDotd = Vector.Dot3(this.HeightDirection, ray.Direction);
if (hDotd != 0)
{
float basePlaneT = Vector.Dot3(this.HeightDirection, this.BasePoint) - Vector.Dot3(this.HeightDirection, ray.Start);
basePlaneT = basePlaneT / hDotd;
if (basePlaneT > 0 && IsCap(this.BasePoint, basePlaneT * ray.Direction + ray.Start) && basePlaneT < first_t)
{
intersectionType = IntersectionType.Base;
first_t = basePlaneT;
}
float endPlaneT = Vector.Dot3(this.HeightDirection, this.EndPoint) - Vector.Dot3(this.HeightDirection, ray.Start);
endPlaneT = endPlaneT / hDotd;
if (endPlaneT > 0 && IsCap(this.EndPoint, endPlaneT * ray.Direction + ray.Start) && endPlaneT < first_t)
{
intersectionType = IntersectionType.End;
first_t = endPlaneT;
}
}
if (first_t == float.MaxValue)
return false;
// t*d
diff = ray.Direction * first_t;
// e + t*d
worldCoords = diff + ray.Start;
float distance = diff.Magnitude3();
if (distance <= record.Distance && distance <= ray.MaximumTravelDistance)
{
if (ray.UseBounds)
{
float cameraOrthogonalDistance = Math.Abs(Vector.Dot3(diff, ray.CameraLookDirection));
if (cameraOrthogonalDistance > far && cameraOrthogonalDistance < near)
{
return false;
}
}
record.T = first_t;
record.HitPoint = ray.Start + diff;
record.Distance = distance;
record.Material = this.Material;
if (intersectionType == IntersectionType.Cylinder)
{
record.SurfaceNormal = SurfaceNormal(record.HitPoint, ray.Direction);
if (Material.TextureImage != null)
{
float heightReached = Vector.Dot3(HeightDirection, record.HitPoint - this.BasePoint);
float u = heightReached / Height;
Vector circCenter = BasePoint + HeightDirection * heightReached;
Vector projection = record.HitPoint - circCenter;
projection.Normalize3();
float similarity = Vector.Dot3(projection, Tangent);
float theta = (float)Math.Acos(similarity);
float v = (float)((Math.PI - theta) / Math.PI);
v = v < 0 ? -v : v;
record.TextureColor = this.Material.GetTexturePixelColor(u, v);
// float v =
}
}
else
{
record.SurfaceNormal = PlaneNormal(record.HitPoint, ray.Direction);
if (Material.TextureImage != null)
{
Vector circCenter = intersectionType == IntersectionType.Base ? BasePoint : EndPoint;
Vector projection = record.HitPoint - circCenter;
float length = projection.Magnitude3();
projection.Normalize3();
float similarity = Vector.Dot3(projection, Tangent);
float theta = (float)Math.Acos(similarity);
float u = length / Radius;
float v = (float)((Math.PI - theta) / Math.PI);
v = v < 0 ? -v : v;
record.TextureColor = this.Material.GetTexturePixelColor(u, v);
// float v =
}
}
// record.SurfaceNormal = SurfaceNormal(record.HitPoint, ray.Direction);
return true;
}
return false;
}
public override bool IsHit(Ray ray, HitRecord record, float near, float far)
{
bool isHit = false;
foreach (SceneTriangle triangle in triangles)
{
isHit = triangle.IsHit(ray, record, near, far) || isHit;
}
if (isHit)
{
record.ObjectName = this.Name;
if (Material.TextureImage != null)
{
Vector l1 = Vertex[1] - Vertex[0];
Vector l2 = Vertex[3] - Vertex[0];
float f = l1.x;
float g = l2.x;
float h = record.HitPoint.x;
float i = Vertex[0].x;
float j = l1.y;
float k = l2.y;
float l = record.HitPoint.y;
float m = Vertex[0].y;
float n = l1.z;
float o = l2.z;
float p = record.HitPoint.z;
float q = Vertex[0].z;
float det = g * j - f * k;
if (det == 0)
{
det = o * j - n * k;
if (det == 0)
{
det = g * n - f * o;
j = n;
k = o;
l = p;
m = q;
}
else
{
f = n;
h = o;
h = p;
i = q;
}
}
if (det != 0)
{
float alpha = (g * l - g * m - h * k + i * k) / det;
float beta = (-f * l + f * m + h * j - i * j) / det;
//if (RenderingParameters.showMouse)
//{
//Console.WriteLine("alpha: " + alpha + "\tbeta: " + beta);
record.TextureColor = this.Material.GetTexturePixelColor(alpha, beta);
}
// }
}
}
return isHit;
}
public abstract bool IsHit(Ray ray, HitRecord record, float near, float far);
public override bool IsHit(Ray ray, HitRecord record, float near, float far)
{
//Vamos precalculando variables auxiliares para facilitar el calculo y aumentar eficiencia
//Convencion de nombres usada es la misma del libro "Fundamentals of Computer Graphics":
/*
* | a d g | | beta | | j |
* | b e h | | gamma | = | k |
* | c f i | | t | = | l |
*/
float a = Vertex[0].x - Vertex[1].x;
float b = Vertex[0].y - Vertex[1].y;
float c = Vertex[0].z - Vertex[1].z;
float d = Vertex[0].x - Vertex[2].x;
float e = Vertex[0].y - Vertex[2].y;
float f = Vertex[0].z - Vertex[2].z;
float g = ray.Direction.x;
float h = ray.Direction.y;
float i = ray.Direction.z;
float j = Vertex[0].x - ray.Start.x;
float k = Vertex[0].y - ray.Start.y;
float l = Vertex[0].z - ray.Start.z;
float eiMinushf = e * i - h * f;
float gfMinusdi = g * f - d * i;
float dhMinuseg = d * h - e * g;
float akMinusjb = a * k - j * b;
float jcMinusal = j * c - a * l;
float blMinuskc = b * l - k * c;
float M = a * eiMinushf + b * gfMinusdi + c * dhMinuseg;
//e + td = punto triangulo
float t = -(f * akMinusjb + e * jcMinusal + d * blMinuskc) / M;
if (t >= 0)
{
float gamma = (i * akMinusjb + h * jcMinusal + g * blMinuskc) / M;
if (gamma >= 0)
{
float beta = (j * eiMinushf + k * gfMinusdi + l * dhMinuseg) / M;
//alpha = 1 - beta - gamma
if (beta >= 0 && 1 - beta - gamma >= 0)
{
Vector diff = t * ray.Direction;
float distance = diff.Magnitude3();
if (distance <= record.Distance && distance <= ray.MaximumTravelDistance)
{
if (ray.UseBounds)
{
float cameraOrthogonalDistance = Math.Abs(Vector.Dot3(diff, ray.CameraLookDirection));
if (cameraOrthogonalDistance > far && cameraOrthogonalDistance < near)
{
return false;
}
}
record.T = t;
record.HitPoint = ray.Start + diff;
record.Distance = distance;
record.Material = Materials[0];
record.SurfaceNormal = SurfaceNormal(record.HitPoint, ray.Direction);
if (record.Material.TextureImage != null)
{
float alpha = 1 - beta - gamma;
float u = alpha * U[0] + beta * U[1] + gamma * U[2];
float v = alpha * V[0] + beta * V[1] + gamma * V[2];
record.TextureColor = record.Material.GetTexturePixelColor(u, v);
}
return true;
}
}
}
}
return false;
}
