/// <summary>
/// Finds where a line hits the plane, if anywhere.
/// </summary>
/// <param name="start">The start of the line.</param>
/// <param name="end">The end of the line.</param>
/// <returns>A location of the hit, or NaN if none.</returns>
public Location IntersectLine(Location start, Location end)
{
Location ba = end - start;
double nDotA = Normal.Dot(start);
double nDotBA = Normal.Dot(ba);
double t = -(nDotA + D) / (nDotBA);
if (t < 0) // || t > 1
{
return(Location.NaN);
}
return(start + t * ba);
}
public Plane(Location v1, Location v2, Location v3)
{
vec1 = v1;
vec2 = v2;
vec3 = v3;
Normal = (v2 - v1).CrossProduct(v3 - v1).Normalize();
D = -(Normal.Dot(vec1));
}
public Plane(Location v1, Location v2, Location v3, Location _normal)
{
vec1 = v1;
vec2 = v2;
vec3 = v3;
Normal = _normal;
D = -(Normal.Dot(vec1));
}
public static Matrix LookAtLH(Location start, Location end, Location up)
{
Location zAxis = (end - start).Normalize();
Location xAxis = up.CrossProduct(zAxis).Normalize();
Location yAxis = zAxis.CrossProduct(xAxis);
return(new Matrix((double)xAxis.X, (double)yAxis.X, (double)zAxis.X, 0, (double)xAxis.Y,
(double)yAxis.Y, (double)zAxis.Y, 0, (double)xAxis.Z, (double)yAxis.Z, (double)zAxis.Z, 0,
(double)-xAxis.Dot(start), (double)-yAxis.Dot(start), (double)-zAxis.Dot(start), 1));
}