public void Accumulate(System.Drawing.Point pixel, Ray r, double t) {
PerPixel pp = _grid[pixel];
if (pp == null) {
pp = new PerPixel(_max_entries, r, t);
_grid[pixel] = pp;
} else {
pp.Add(t);
}
}
/// <summary>
/// Ray/Plane intersection
/// </summary>
/// <param name="r">Ray</param>
/// <param name="p">Plane</param>
/// <param name="t">Parametric t</param>
/// <returns></returns>
public static bool RayPlane(Ray r, Plane p, out double t) {
// http://www.siggraph.org/education/materials/HyperGraph/raytrace/rayplane_intersection.htm
double denom = Vector.ScalarProduct(p.Normal, r.Direction);
if (Math.Abs(denom) > 1e-10) {
// Since the ray passes through the origin, the intersection calculation can
// be greatly simplified.
t = -p.D / denom;
return true;
} else {
t = Double.MaxValue;
return false;
}
}
/// <summary>
/// Find best intersection of eye-rays and reference planes.
/// </summary>
/// <remarks>Best is defined as the the plane with the shortest distance</remarks>
/// <param name="eye_rays">Eye-rays</param>
/// <param name="planes">Calibrated reference planes</param>
/// <param name="isect_t">Parametric ray intersection distance</param>
/// <param name="isect_p">Intersection points (optional).</param>
public static void FindEyeRayPlaneIntersections(Ray[] eye_rays, Plane[] planes, out double[] isect_t, out Vector[] isect_p, out int[] isect_plane_ids) {
isect_t = new double[eye_rays.Length];
isect_p = new Vector[eye_rays.Length];
isect_plane_ids = new int[eye_rays.Length];
for (int i = 0; i < eye_rays.Length; ++i) {
Ray r = eye_rays[i];
double t = Double.MaxValue;
int id = -1;
for (int p = 0; p < planes.Length; ++p) {
double this_t;
Intersection.RayPlane(r, planes[p], out this_t);
if (this_t < t) {
t = this_t;
id = p;
}
}
isect_t[i] = t;
isect_p[i] = r.At(t);
isect_plane_ids[i] = id;
}
}
/// <summary>
/// Construct eye-rays through the specified pixels
/// </summary>
/// <param name="icp">Intrinsic camera parameters</param>
/// <param name="pixels">Pixels</param>
/// <returns>Enumerable ray collection</returns>
public static Ray[] EyeRays(Emgu.CV.IntrinsicCameraParameters icp, PointF[] pixels) {
Ray[] rays = new Ray[pixels.Length];
if (pixels.Length > 0) {
// 1. Undistort pixels
PointF[] undistorted_pixels = icp.Undistort(pixels, null, icp.IntrinsicMatrix);
// 2. Create rays
// Use inverse intrinsic calibration and depth = 1
double cx = icp.IntrinsicMatrix.Data[0, 2];
double cy = icp.IntrinsicMatrix.Data[1, 2];
double fx = icp.IntrinsicMatrix.Data[0, 0];
double fy = icp.IntrinsicMatrix.Data[1, 1];
Vector direction = new Vector(3);
for (int i = 0; i < undistorted_pixels.Length; ++i) {
PointF pixel = undistorted_pixels[i];
direction[0] = (pixel.X - cx) / fx;
direction[1] = (pixel.Y - cy) / fy;
direction[2] = 1;
rays[i] = new Ray(direction.Normalize());
}
}
return rays;
}
/// <summary>
/// Construct from capacity and first entry
/// </summary>
/// <param name="capacity"></param>
/// <param name="first"></param>
public PerPixel(int capacity, Ray r, double t) {
_ts = new List<double>(capacity);
_ts.Add(t);
_r = r;
}
/// <summary>
/// Construct PerPixel from first entry:
/// Since this the first t-value is passed to the constructor,
/// t_mean is set to t.
/// </summary>
/// <param name="first"></param>
public PerPixel(Ray r, double t) {
_tmean = t;
_r = r;
_t_count = 1;
}
public void At() {
Ray r = new Ray(MakeVector(1, 0, 0));
Assert.AreEqual(0, (MakeVector(1, 0, 0) - r.At(1)).Norm(), 0.00001);
Assert.AreEqual(0, (MakeVector(5, 0, 0) - r.At(5)).Norm(), 0.00001);
}
public void Construction() {
Ray r = new Ray(MakeVector(1, 0, 0));
Assert.AreEqual(0, (MakeVector(1, 0, 0) - r.Direction).Norm(), 0.0001);
}
