raytracing

Quote:

2) in shadow tests, how do you deal with refraction? I mean you can cast a ray to the light. If it hits a transparent primitive, it wouldn't prolly hit the light then. But that doesn't mean another ray from the light wouldn't! It might go a bit to the side and refract just the way we need. How do we deal with this?

using System;using Math;namespace Raytrace{	/// <summary>	/// CSphere Stores specific information and methods for 	/// creating and modifying a sphere for use in the raytace's 	/// graphics function	/// </summary>	public class CSphere : Raytrace.CShape	{				/// <summary>		/// Creates a sphere with a radius of 0 at location {0,0,0}		/// </summary>		public CSphere()		{			Radius = 0;			Location = new Math.CVector(0,0,0);		}						/// <summary>		/// Radius of the sphere		/// </summary>		public double Radius;				/// <summary>		/// Location holds the position of the CSphere 		/// in object space		/// </summary>		public CVector Location;				/// <summary>		/// Intersection function used to check for intersection 		/// of CRay and CSphere		/// </summary>		/// <param name="CheckRay">CRay to check for intersection 		/// with CSphere</param>		/// <param name="Intersect">CVector that the closest 		/// intersection point will be saved to _if_ CheckIntersect 		/// returns true </param>		/// <returns>		/// CheckIntersect returns true if the CRay intersects		/// this CSphere and sets Intersect to closest intersection		/// CheckIntersect returns false if the CRay does not 		/// intersect this CSphere and sets Intersect to {0,0,0}		/// </returns>		public override bool CheckIntersect(CRay CheckRay, 			ref CVector Intersect)		{			CVector RayDirection = new CVector(CheckRay.DirectionVector());			CVector StartToSphere = new CVector(Location.X - CheckRay.RayStart.X,Location.Y - CheckRay.RayStart.Y,Location.Z - CheckRay.RayStart.Z);			double disc, v,d;			v = CVector.DotProduct(StartToSphere,RayDirection);			disc = Radius * Radius - (CVector.DotProduct(RayDirection,RayDirection) - v * v);			if (disc <0)				return (false);			else			{				d = System.Math.Sqrt(disc);				Intersect.X = CheckRay.RayStart.X + (v - d) * RayDirection.X;				Intersect.Y = CheckRay.RayStart.Y + (v - d) * RayDirection.Y;				Intersect.Z = CheckRay.RayStart.Z + (v - d) * RayDirection.Z;			}			return (true);		}				}}