/// <summary>
/// Projects points onto plane (shortest distance).
/// </summary>
public static V3d[] Project(this Plane3d plane, V3d[] pointArray, int startIndex = 0, int count = 0)
{
if (pointArray == null)
{
throw new ArgumentNullException();
}
if (startIndex < 0 || startIndex >= pointArray.Length)
{
throw new ArgumentOutOfRangeException();
}
if (count < 0 || startIndex + count >= pointArray.Length)
{
throw new ArgumentOutOfRangeException();
}
if (count == 0)
{
count = pointArray.Length - startIndex;
}
var normal = plane.Normal;
var result = new V3d[count];
for (int i = startIndex, j = 0; j < count; i++, j++)
{
var p = pointArray[i];
var height = plane.Height(p);
result[j] = p - height * normal;
}
return(result);
}
public bool HitsCylinder(Cylinder3d cylinder,
double tmin, double tmax,
ref RayHit3d hit)
{
var axisDir = cylinder.Axis.Direction.Normalized;
// Vector Cyl.P0 -> Ray.Origin
var op = Origin - cylinder.P0;
// normal RayDirection - CylinderAxis
var normal = Direction.Cross(axisDir);
var unitNormal = normal.Normalized;
// normal (Vec Cyl.P0 -> Ray.Origin) - CylinderAxis
var normal2 = op.Cross(axisDir);
var t = -normal2.Dot(unitNormal) / normal.Length;
var radius = cylinder.Radius;
if (cylinder.DistanceScale != 0)
{ // cylinder gets bigger, the further away it is
var pnt = GetPointOnRay(t);
var dis = V3d.Distance(pnt, this.Origin);
radius = ((cylinder.Radius / cylinder.DistanceScale) * dis) * 2;
}
// between enitre rays (caps are ignored)
var shortestDistance = Fun.Abs(op.Dot(unitNormal));
if (shortestDistance <= radius)
{
var s = Fun.Abs(Fun.Sqrt(radius.Square() - shortestDistance.Square()) / Direction.Length);
var t1 = t - s; // first hit of Cylinder shell
var t2 = t + s; // second hit of Cylinder shell
if (t1 > tmin && t1 < tmax)
{
tmin = t1;
}
if (t2 < tmax && t2 > tmin)
{
tmax = t2;
}
hit.T = t1;
hit.Point = GetPointOnRay(t1);
// check if found point is outside of Cylinder Caps
var bottomPlane = new Plane3d(cylinder.Circle0.Normal, cylinder.Circle0.Center);
var topPlane = new Plane3d(cylinder.Circle1.Normal, cylinder.Circle1.Center);
var heightBottom = bottomPlane.Height(hit.Point);
var heightTop = topPlane.Height(hit.Point);
// t1 lies outside of caps => find closest cap hit
if (heightBottom > 0 || heightTop > 0)
{
hit.T = tmax;
// intersect with bottom Cylinder Cap
var bottomHit = HitsPlane(bottomPlane, tmin, tmax, ref hit);
// intersect with top Cylinder Cap
var topHit = HitsPlane(topPlane, tmin, tmax, ref hit);
// hit still close enough to cylinder axis?
var distance = cylinder.Axis.Ray3d.GetMinimalDistanceTo(hit.Point);
if (distance <= radius && (bottomHit || topHit))
{
return(true);
}
}
else
{
return(true);
}
}
hit.T = tmax;
hit.Point = V3d.NaN;
return(false);
}
/// <summary> /// Projects a point onto the plane (shortest distance). /// </summary> public static V3d Project(this Plane3d plane, V3d p) => p - plane.Height(p) * plane.Normal;
/// <summary>
/// Projects a point onto the plane (shortest distance).
/// </summary>
public static V3d Project(this Plane3d plane, V3d p)
{
return(p - plane.Height(p) * plane.Normal);
}