OpenSim.Region.Framework.Scenes.SceneObjectPart.TestIntersection C# (CSharp) Method

        public EntityIntersection TestIntersection(Ray iray, Quaternion parentrot)
        {
            // In this case we're using a sphere with a radius of the largest dimension of the prim
            // TODO: Change to take shape into account

            EntityIntersection result = new EntityIntersection();
            Vector3 vAbsolutePosition = AbsolutePosition;
            Vector3 vScale = Scale;
            Vector3 rOrigin = iray.Origin;
            Vector3 rDirection = iray.Direction;

            //rDirection = rDirection.Normalize();
            // Buidling the first part of the Quadratic equation
            Vector3 r2ndDirection = rDirection*rDirection;
            float itestPart1 = r2ndDirection.X + r2ndDirection.Y + r2ndDirection.Z;

            // Buidling the second part of the Quadratic equation
            Vector3 tmVal2 = rOrigin - vAbsolutePosition;
            Vector3 r2Direction = rDirection*2.0f;
            Vector3 tmVal3 = r2Direction*tmVal2;

            float itestPart2 = tmVal3.X + tmVal3.Y + tmVal3.Z;

            // Buidling the third part of the Quadratic equation
            Vector3 tmVal4 = rOrigin*rOrigin;
            Vector3 tmVal5 = vAbsolutePosition*vAbsolutePosition;

            Vector3 tmVal6 = vAbsolutePosition*rOrigin;

            // Set Radius to the largest dimension of the prim
            float radius = 0f;
            if (vScale.X > radius)
                radius = vScale.X;
            if (vScale.Y > radius)
                radius = vScale.Y;
            if (vScale.Z > radius)
                radius = vScale.Z;

            // the second part of this is the default prim size
            // once we factor in the aabb of the prim we're adding we can
            // change this to;
            // radius = (radius / 2) - 0.01f;
            //
            radius = (radius / 2) + (0.5f / 2) - 0.1f;

            //radius = radius;

            float itestPart3 = tmVal4.X + tmVal4.Y + tmVal4.Z + tmVal5.X + tmVal5.Y + tmVal5.Z -
                               (2.0f*(tmVal6.X + tmVal6.Y + tmVal6.Z + (radius*radius)));

            // Yuk Quadradrics..    Solve first
            float rootsqr = (itestPart2*itestPart2) - (4.0f*itestPart1*itestPart3);
            if (rootsqr < 0.0f)
            {
                // No intersection
                return result;
            }
            float root = ((-itestPart2) - (float) Math.Sqrt((double) rootsqr))/(itestPart1*2.0f);

            if (root < 0.0f)
            {
                // perform second quadratic root solution
                root = ((-itestPart2) + (float) Math.Sqrt((double) rootsqr))/(itestPart1*2.0f);

                // is there any intersection?
                if (root < 0.0f)
                {
                    // nope, no intersection
                    return result;
                }
            }

            // We got an intersection.  putting together an EntityIntersection object with the
            // intersection information
            Vector3 ipoint =
                new Vector3(iray.Origin.X + (iray.Direction.X*root), iray.Origin.Y + (iray.Direction.Y*root),
                            iray.Origin.Z + (iray.Direction.Z*root));

            result.HitTF = true;
            result.ipoint = ipoint;

            // Normal is calculated by the difference and then normalizing the result
            Vector3 normalpart = ipoint - vAbsolutePosition;
            result.normal = normalpart / normalpart.Length();

            // It's funny how the Vector3 object has a Distance function, but the Axiom.Math object doesn't.
            // I can write a function to do it..    but I like the fact that this one is Static.

            Vector3 distanceConvert1 = new Vector3(iray.Origin.X, iray.Origin.Y, iray.Origin.Z);
            Vector3 distanceConvert2 = new Vector3(ipoint.X, ipoint.Y, ipoint.Z);
            float distance = (float) Util.GetDistanceTo(distanceConvert1, distanceConvert2);

            result.distance = distance;

            return result;
        }