diff --git a/Curve/CubicBezierCurve2D.cs b/Curve/CubicBezierCurve2D.cs
index ac5b61a..9f3f710 100644
--- a/Curve/CubicBezierCurve2D.cs
+++ b/Curve/CubicBezierCurve2D.cs
@@ -3,13 +3,35 @@ using MoonTools.Core.Curve.Extensions;
 
 namespace MoonTools.Core.Curve
 {
+    /// <summary>
+    /// A 2-dimensional Bezier curve defined by 4 points.
+    /// </summary>
     public struct CubicBezierCurve2D
     {
+        /// <summary>
+        /// The start point.
+        /// </summary>
         public Vector2 p0;
+
+        /// <summary>
+        /// The first control point.
+        /// </summary>
         public Vector2 p1;
+
+        /// <summary>
+        /// The second control point.
+        /// </summary>
         public Vector2 p2;
+
+        /// <summary>
+        /// The end point.
+        /// </summary>
         public Vector2 p3;
 
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
         public CubicBezierCurve2D(Vector2 p0, Vector2 p1, Vector2 p2, Vector2 p3)
         {
             this.p0 = p0;
@@ -18,10 +40,42 @@ namespace MoonTools.Core.Curve
             this.p3 = p3;
         }
 
+        /// <summary>
+        /// Returns the curve coordinate given by t.
+        /// </summary>
+        /// <param name="t">A value between 0 and 1.</param>
         public Vector2 Point(float t) => Point(p0, p1, p2, p3, t);
-        public Vector2 Point(float t, float minT, float maxT) => Point(p0, p1, p2, p3, t, minT, maxT);
+
+        /// <summary>
+        /// Returns the curve coordinate given by a normalized time value.
+        /// </summary>
+        /// <param name="t">A value between startTime and endTime.</param>
+        /// <param name="startTime"></param>
+        /// <param name="endTime"></param>
+        public Vector2 Point(float t, float startTime, float endTime) => Point(p0, p1, p2, p3, t, startTime, endTime);
+
+        /// <summary>
+        /// Returns the instantaneous velocity on the curve given by t.
+        /// </summary>
+        /// <param name="t">A value between 0 and 1.</param>
         public Vector2 Velocity(float t) => Velocity(p0, p1, p2, p3, t);
-        public Vector2 Velocity(float t, float minT, float maxT) => Velocity(p0, p1, p2, p3, TimeHelper.Normalized(t, minT, maxT));
+
+        /// <summary>
+        /// Returns the instantaneous velocity on the curve given by a normalized time value.
+        /// </summary>
+        /// <param name="t">A value between startTime and endTime.</param>
+        /// <param name="startTime"></param>
+        /// <param name="endTime"></param>
+        public Vector2 Velocity(float t, float startTime, float endTime) => Velocity(p0, p1, p2, p3, TimeHelper.Normalized(t, startTime, endTime));
+
+        /// <summary>
+        /// Returns the curve coordinate given by 4 points and a time value.
+        /// </summary>
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
+        /// <param name="t">A value between 0 and 1.</param>
         public static Vector2 Point(Vector2 p0, Vector2 p1, Vector2 p2, Vector2 p3, float t)
         {
             return CubicBezierCurve3D.Point(
@@ -33,11 +87,29 @@ namespace MoonTools.Core.Curve
             ).XY();
         }
 
-        public static Vector2 Point(Vector2 p0, Vector2 p1, Vector2 p2, Vector2 p3, float t, float minT, float maxT)
+        /// <summary>
+        /// Returns the curve coordinate given by 4 points and a normalized time value.
+        /// </summary>
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
+        /// <param name="t">A value between startTime and endTime.</param>
+        /// <param name="startTime"></param>
+        /// <param name="endTime"></param>
+        public static Vector2 Point(Vector2 p0, Vector2 p1, Vector2 p2, Vector2 p3, float t, float startTime, float endTime)
         {
-            return Point(p0, p1, p2, p3, TimeHelper.Normalized(t, minT, maxT));
+            return Point(p0, p1, p2, p3, TimeHelper.Normalized(t, startTime, endTime));
         }
 
+        /// <summary>
+        /// Returns the instantaneous velocity given by 4 points and a time value.
+        /// </summary>
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
+        /// <param name="t">A value between 0 and 1.</param>
         public static Vector2 Velocity(Vector2 p0, Vector2 p1, Vector2 p2, Vector2 p3, float t)
         {
             return CubicBezierCurve3D.Velocity(
@@ -49,6 +121,16 @@ namespace MoonTools.Core.Curve
             ).XY();
         }
 
+        /// <summary>
+        /// Returns the instantaneous velocity given by 4 points and a normalized time value.
+        /// </summary>
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
+        /// <param name="t">A value between startTime and endTime.</param>
+        /// <param name="startTime"></param>
+        /// <param name="endTime"></param>
         public static Vector2 Velocity(Vector2 p0, Vector2 p1, Vector2 p2, Vector2 p3, float t, float minT, float maxT)
         {
             return Velocity(p0, p1, p2, p3, TimeHelper.Normalized(t, minT, maxT));
diff --git a/Curve/CubicBezierCurve3D.cs b/Curve/CubicBezierCurve3D.cs
index eebaf37..4bc27af 100644
--- a/Curve/CubicBezierCurve3D.cs
+++ b/Curve/CubicBezierCurve3D.cs
@@ -2,13 +2,35 @@ using System.Numerics;
 
 namespace MoonTools.Core.Curve
 {
+    /// <summary>
+    /// A 3-dimensional Bezier curve defined by 4 points.
+    /// </summary>
     public struct CubicBezierCurve3D
     {
+        /// <summary>
+        /// The start point.
+        /// </summary>
         public Vector3 p0;
+
+        /// <summary>
+        /// The first control point.
+        /// </summary>
         public Vector3 p1;
+
+        /// <summary>
+        /// The second control point.
+        /// </summary>
         public Vector3 p2;
+
+        /// <summary>
+        /// The end point.
+        /// </summary>
         public Vector3 p3;
 
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
         public CubicBezierCurve3D(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3)
         {
             this.p0 = p0;
@@ -17,14 +39,42 @@ namespace MoonTools.Core.Curve
             this.p3 = p3;
         }
 
+        /// <summary>
+        /// Returns the curve coordinate given by t.
+        /// </summary>
+        /// <param name="t">A value between 0 and 1.</param>
         public Vector3 Point(float t) => Point(p0, p1, p2, p3, t);
 
-        public Vector3 Point(float t, float minT, float maxT) => Point(p0, p1, p2, p3, t, minT, maxT);
+        /// <summary>
+        /// Returns the curve coordinate given by a normalized time value.
+        /// </summary>
+        /// <param name="t"></param>
+        /// <param name="startTime"></param>
+        /// <param name="endTime"></param>
+        public Vector3 Point(float t, float startTime, float endTime) => Point(p0, p1, p2, p3, t, startTime, endTime);
 
+        /// <summary>
+        /// Returns the instantaneous velocity on the curve given by t.
+        /// </summary>
+        /// <param name="t">A value between 0 and 1.</param>
         public Vector3 Velocity(float t) => Velocity(p0, p1, p2, p3, t);
 
-        public Vector3 Velocity(float t, float minT, float maxT) => Velocity(p0, p1, p2, p3, t, minT, maxT);
+        /// <summary>
+        /// Returns the instantaneous velocity on the curve given by a normalized time value.
+        /// </summary>
+        /// <param name="t">A value between 0 and 1.</param>
+        /// <param name="startTime"></param>
+        /// <param name="endTime"></param>
+        public Vector3 Velocity(float t, float startTime, float endTime) => Velocity(p0, p1, p2, p3, t, startTime, endTime);
 
+        /// <summary>
+        /// Returns the curve coordinate given by 4 points and a time value.
+        /// </summary>
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
+        /// <param name="t">A value between 0 and 1.</param>
         public static Vector3 Point(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t)
         {
             ArgumentChecker.CheckT(t);
@@ -35,12 +85,30 @@ namespace MoonTools.Core.Curve
                     t * t * t * p3;
         }
 
-        public static Vector3 Point(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t, float minT, float maxT)
+        /// <summary>
+        /// Returns the curve coordinate given by 4 points and a normalized time value.
+        /// </summary>
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
+        /// <param name="t">A value between startTime and endTime.</param>
+        /// <param name="startTime"></param>
+        /// <param name="endTime"></param>
+        public static Vector3 Point(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t, float startTime, float endTime)
         {
-            ArgumentChecker.CheckT(t, minT, maxT);
-            return Point(p0, p1, p2, p3, TimeHelper.Normalized(t, minT, maxT));
+            ArgumentChecker.CheckT(t, startTime, endTime);
+            return Point(p0, p1, p2, p3, TimeHelper.Normalized(t, startTime, endTime));
         }
 
+        /// <summary>
+        /// Returns the instantaneous velocity given by 4 points and a time value.
+        /// </summary>
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
+        /// <param name="t">A value between 0 and 1.</param>
         public static Vector3 Velocity(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t)
         {
             ArgumentChecker.CheckT(t);
@@ -50,10 +118,21 @@ namespace MoonTools.Core.Curve
                     3f * t * t * (p3 - p2);
         }
 
-        public static Vector3 Velocity(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t, float minT, float maxT)
+        /// <summary>
+        /// Returns the instantaneous velocity given by 4 points and a normalized time value.
+        /// </summary>
+        /// <param name="p0">The start point.</param>
+        /// <param name="p1">The first control point.</param>
+        /// <param name="p2">The second control point.</param>
+        /// <param name="p3">The end point.</param>
+        /// <param name="t">A value between startTime and endTime.</param>
+        /// <param name="startTime"></param>
+        /// <param name="endTime"></param>
+        /// <returns></returns>
+        public static Vector3 Velocity(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t, float startTime, float endTime)
         {
-            ArgumentChecker.CheckT(t, minT, maxT);
-            return Velocity(p0, p1, p2, p3, TimeHelper.Normalized(t, minT, maxT));
+            ArgumentChecker.CheckT(t, startTime, endTime);
+            return Velocity(p0, p1, p2, p3, TimeHelper.Normalized(t, startTime, endTime));
         }
     }
 }
\ No newline at end of file