public IntersectResult Intersect(Ray3 ray, double maxDistance)
{
if (!BoundingBox.Intersect(ray, maxDistance))
{
return(IntersectResult.NoHit());
}
if (normal.SqrLength() == 0)
{
return(IntersectResult.NoHit());
}
Vector3 w0 = ray.Origin - vertices[0];
double x = -normal ^ w0;
double y = normal ^ ray.Direction;
double distance = x / y;
if (y == 0 || distance < 0)
{
return(IntersectResult.NoHit());
}
Vector3 position = ray.GetPoint(distance);
double uu = edgeAB ^ edgeAB;
double uv = edgeAB ^ edgeAC;
double vv = edgeAC ^ edgeAC;
Vector3 w = position - vertices[0];
double wu = w ^ (edgeAB);
double wv = w ^ (edgeAC);
double D = uv * uv - uu * vv;
double beta = (uv * wv - vv * wu) / D;
if (beta < 0 || beta > 1)
{
return(IntersectResult.NoHit());
}
double gamma = (uv * wu - uu * wv) / D;
if (gamma < 0 || beta + gamma > 1)
{
return(IntersectResult.NoHit());
}
double alpha = 1 - beta - gamma;
Vector3 newNormal = normal;
if (distance > 0 && normals != null)
{
Vector3 n1Interpolated = normals[0] * alpha;
Vector3 n2Interpolated = normals[1] * beta;
Vector3 n3Interpolated = normals[2] * gamma;
newNormal = n1Interpolated + n2Interpolated + n3Interpolated;
}
IntersectResult result = new IntersectResult(this, distance, position, newNormal);
if (textures != null)
{
Vector2 t1Interpolated = textures[0] * alpha;
Vector2 t2Interpolated = textures[1] * beta;
Vector2 t3Interpolated = textures[2] * gamma;
result.TextureCoordinates = t1Interpolated + t2Interpolated + t3Interpolated;
}
return(result);
}
public override IntersectResult Intersect(Ray3 ray)
{
double a = ray.Direction ^ normal;
if (a >= 0)
{
return(IntersectResult.NoHit());
}
double b = normal ^ (ray.Origin - position);
double distance = -b / a;
return(new IntersectResult(this, distance, ray.GetPoint(distance), normal));
}
public override IntersectResult Intersect(Ray3 ray)
{
Vector3 v = ray.Origin - center;
double a0 = v.SqrLength() - radius * radius;
double DdotV = ray.Direction ^ v;
if (DdotV <= 0)
{
double discr = DdotV * DdotV - a0;
if (discr >= 0)
{
double distance = -DdotV - Math.Sqrt(discr);
Vector3 position = ray.GetPoint(distance);
Vector3 normal = (position - center).Normalize();
IntersectResult result = new IntersectResult(this, distance, position, normal);
result.TextureCoordinates = new Vector2(
(Math.PI + Math.Atan2(position.Z - center.Z, position.X - center.X)) / (Math.PI * 2),
1.0 - ((Math.PI / 2) + Math.Asin((position.Y - center.Y) / radius)) / Math.PI);
return(result);
}
}
return(IntersectResult.NoHit());
}
