public override bool RayIntersects(Ray ray, out float distance)
{
if (CollisionType == CollisionType.Box)
{
return(RayIntersectsBoundingBox(ray, out distance));
}
var pos = Vector3.TransformPosition(Vector3.Zero, Transform);
var sphere = new BSphere(pos, Scale.X / 2f);
return(Ray.IntersectsSphere(ray, sphere, out distance));
}
public static bool IntersectsSphere(Ray ray, BSphere sphere, out float distance)
{
distance = float.NaN;
var a = Vector3.Dot(ray.Direction, ray.Origin - sphere.Center);
var b = (ray.Origin - sphere.Center).Length;
var c = (a * a) - (b * b) + (sphere.Radius * sphere.Radius);
if (c < 0f)
{
return(false);
}
if (NearZero(c))
{
distance = -a;
return(true);
}
var d = (float)Math.Sqrt(c);
distance = Math.Min(-a + d, -a - d);//+|-
return(true);
}