Esempio n. 1
0
	/// Distance between point p and line segment p1, p2
	static double distance(math::vec3 const& p, math::vec3 const& p1, math::vec3 const& p2)
	{
		math::vec3 const v = p2 - p1;
		math::vec3 const w = p - p1;

		double const c1 = w.dot(v);
		double const c2 = v.dot(v);
		double const b = c1 / c2;

		math::vec3 const pb = p1 + v * b;
		return p.distance(pb);
	}
Esempio n. 2
0
	static bool segment_plane_intersect(math::vec3 const& segment_point1, math::vec3 const& segment_point2,
		math::vec3 const&  plane_p0, math::vec3 const&  plane_n, math::vec3& result)
	{
		math::vec3 const dir = (segment_point2 - segment_point1).normalize(); // ray direction
		double const denom = plane_n.dot(dir);
		if (math::is_zero(denom))
		{
			return false; // no intersection: ray is parallel to plane
		}

		math::vec3 const p1 = plane_p0 - segment_point1;
		double const d = p1.dot(plane_n) / denom;
		result = segment_point1 + dir * d; // intersection point
		return true;
	}
Esempio n. 3
0
	static bool segment_sphere_intersect(math::vec3 const& segment_point1, math::vec3 const& segment_point2,
		math::vec3 const& sphere_center, double sphere_radius)
	{
#if 0
		math::vec3 closest_point;
		closest_point.get_nearest_point_on_line(sphere_center, segment_point1, segment_point2);

		math::vec3 const distance = closest_point - sphere_center;
		double const sqr_distance = distance.dot(distance);
		double const sqr_radius = sphere_radius * sphere_radius;

		return sqr_distance <= sqr_radius;
#else
		math::vec3 const p = segment_point1 - sphere_center; // ray_origin - sphere_center
		math::vec3 const d = (segment_point2 - segment_point1).normalize(); // ray_direction

		double const a = d.dot(d);
		double const b = 2 * d.dot(p);
		double const c = p.dot(p) - sphere_radius * sphere_radius;

		double const D = b * b - 4 * a * c;

		if (D >= 0)
		{
			/*
			intersection points:

			double t[2];
			t[0] = (-b - sqrt(D)) / (2 * a);
			t[1] = (-b + sqrt(D)) / (2 * a);

			math::vec3 result[2];
			result[0] = segment_point1 + d * t[0];
			result[1] = segment_point1 + d * t[1];
			*/
			return true;
		}
		return false;
#endif
	}