diff --git a/Intersection/IntrLine2dBox2d.cs b/Intersection/IntrLine2dBox2d.cs
index 32054615941b22002652b43c257042373303b8ae..2d1ea372a5bd91bd523da42b01147e3275afde30 100644
--- a/Intersection/IntrLine2dBox2d.cs
+++ b/Intersection/IntrLine2dBox2d.cs
@@ -25,22 +25,15 @@ namespace Oroxylum
 
         public IntrLine2dBox2d(Line2d line, Box2d box)
         {
-            LineParam0 = 0;
-            LineParam1 = 0;
+            LineParam0 = -float.MaxValue;
+            LineParam1 = float.MaxValue;
             Point0 = 0;
             Point1 = 0;
             Result = E_IntersectionResult.NotComputed;
             Type = E_IntersectionType.Empty;
             Quantity = 0;
 
-            float2 direction = line.Direction;
-
-            if (!direction.IsNormalized())
-                direction = math.normalize(direction);
-
-            LineParam0 = -float.MaxValue;
-            LineParam1 = float.MaxValue;
-            DoClipping(ref LineParam0, ref LineParam1, line.Origin, direction, box,
+            DoClipping(ref LineParam0, ref LineParam1, line.Origin, line.Direction, box,
                       true, ref Quantity, ref Point0, ref Point1, ref Type);
 
             Result = (Type != E_IntersectionType.Empty) ?
diff --git a/Intersection/IntrLine3dBox3d.cs b/Intersection/IntrLine3dBox3d.cs
index 8d2fc7008949b3292efbf03eb25a2dbbd9fc9360..775c7ca3a1ed3c9676bad3c3c4f0f94f9c752f71 100644
--- a/Intersection/IntrLine3dBox3d.cs
+++ b/Intersection/IntrLine3dBox3d.cs
@@ -8,14 +8,127 @@
 */
 
 
+using Unity.Mathematics;
+
 namespace Oroxylum
 {
     /// <summary>
     /// 相交计算结果：3d直线与3dBox
     /// </summary>
-    public class IntrLine3dBox3d 
+    public struct IntrLine3dBox3d
     {
+        public int Quantity;
+        public E_IntersectionResult Result;
+        public E_IntersectionType Type;
+        public float LineParam0, LineParam1;
+        public float3 Point0;
+        public float3 Point1;
+
+        public IntrLine3dBox3d(Line3d line, Box3d box)
+        {
+            Result = E_IntersectionResult.NotComputed;
+            Type = E_IntersectionType.Empty;
+            LineParam0 = -float.MaxValue;
+            LineParam1 = float.MaxValue;
+            Point0 = 0;
+            Point1 = 1;
+            Quantity = 0;
+
+            DoClipping(ref LineParam0, ref LineParam1, line.Origin, line.Direction, box,
+                      true, ref Quantity, ref Point0, ref Point1, ref Type);
+
+            Result = (Type != E_IntersectionType.Empty) ?
+                E_IntersectionResult.Intersects : E_IntersectionResult.NoIntersection;
+        }
+
+        public static bool DoClipping(ref float t0, ref float t1,
+                         float3 origin, float3 direction,
+                         Box3d box, bool solid, ref int quantity,
+                         ref float3 point0, ref float3 point1,
+                         ref E_IntersectionType intrType)
+        {
+            // Convert linear component to box coordinates.
+            float3 diff = origin - box.Center;
+            float3 BOrigin = new float3(
+                diff.Dot(box.AxisX),
+                diff.Dot(box.AxisY),
+                diff.Dot(box.AxisZ)
+            );
+            float3 BDirection = new float3(
+                direction.Dot(box.AxisX),
+                direction.Dot(box.AxisY),
+                direction.Dot(box.AxisZ)
+            );
+
+            double saveT0 = t0, saveT1 = t1;
+            bool notAllClipped =
+                Clip(+BDirection.x, -BOrigin.x - box.Extent.x, ref t0, ref t1) &&
+                Clip(-BDirection.x, +BOrigin.x - box.Extent.x, ref t0, ref t1) &&
+                Clip(+BDirection.y, -BOrigin.y - box.Extent.y, ref t0, ref t1) &&
+                Clip(-BDirection.y, +BOrigin.y - box.Extent.y, ref t0, ref t1) &&
+                Clip(+BDirection.z, -BOrigin.z - box.Extent.z, ref t0, ref t1) &&
+                Clip(-BDirection.z, +BOrigin.z - box.Extent.z, ref t0, ref t1);
+
+            if (notAllClipped && (solid || t0 != saveT0 || t1 != saveT1))
+            {
+                if (t1 > t0)
+                {
+                    intrType = E_IntersectionType.LineSegment;
+                    quantity = 2;
+                    point0 = origin + t0 * direction;
+                    point1 = origin + t1 * direction;
+                }
+                else
+                {
+                    intrType = E_IntersectionType.Point;
+                    quantity = 1;
+                    point0 = origin + t0 * direction;
+                }
+            }
+            else
+            {
+                quantity = 0;
+                intrType = E_IntersectionType.Empty;
+            }
+
+            return intrType != E_IntersectionType.Empty;
+        }
+
+        private static bool Clip(float denom, float numer, ref float t0, ref float t1)
+        {
+            // Return value is 'true' if line segment intersects the current test
+            // plane.  Otherwise 'false' is returned in which case the line segment
+            // is entirely clipped.
+
+            if (denom > 0)
+            {
+                if (numer - denom * t1 > OMath.ZeroTolerance)
+                {
+                    return false;
+                }
+                if (numer > denom * t0)
+                {
+                    t0 = numer / denom;
+                }
+                return true;
+            }
+            else if (denom < 0)
+            {
+                if (numer - denom * t0 > OMath.ZeroTolerance)
+                {
+                    return false;
+                }
+                if (numer > denom * t1)
+                {
+                    t1 = numer / denom;
+                }
+                return true;
+            }
+            else
+            {
+                return numer <= 0;
+            }
+        }
 
-        
     }
-}
+}
\ No newline at end of file
diff --git a/Math/Box3d.cs b/Math/Box3d.cs
index 45c3099c4f6b41bf1e568cfc1a8aa364ae513c02..76e5f0f8b662b90f99d2aee4b6f449238349397c 100644
--- a/Math/Box3d.cs
+++ b/Math/Box3d.cs
@@ -8,6 +8,8 @@
 */
 
 
+using Unity.Mathematics;
+
 namespace Oroxylum
 {
     /// <summary>
@@ -15,6 +17,13 @@ namespace Oroxylum
     /// </summary>
     public struct Box3d
     {
+        public float3 Center;
+        public float3 Extent;
+
+         public  float3 AxisX => new float3(1.0f, 0.0f, 0.0f);
+         public  float3 AxisY => new float3(0.0f, 1.0f, 0.0f);
+         public  float3 AxisZ => new float3(0.0f, 0.0f, 1.0f);
+
 
 
     }
diff --git a/Math/Line2d.cs b/Math/Line2d.cs
index 3781f885ed6ba8468e5ae8e680b5f0326509dd9a..c64a16f49f43f09540554f79056602875277476f 100644
--- a/Math/Line2d.cs
+++ b/Math/Line2d.cs
@@ -18,13 +18,16 @@ namespace Oroxylum
     public struct Line2d
     {
         public float2 Origin;
-        public float2 Direction;
 
+        /// <summary>
+        /// 直线方向，已经 normalize
+        /// </summary>
+        public float2 Direction;
 
         public Line2d(float2 origin, float2 direction)
         {
             this.Origin = origin;
-            this.Direction = direction;
+            this.Direction = math.normalize(direction);
         }
 
         public static Line2d FromPoints(float2 p0, float2 p1)
@@ -37,7 +40,7 @@ namespace Oroxylum
         public float2 ClosestPoint(float2 p)
         {
             float t = (p - Origin).Dot(Direction);
-            return Origin + t * Direction;
+            return Origin + (t * Direction);
         }
 
         public double DistanceSquared(float2 p)