unity3d 图形吧 之 场景中画圆



孙广东：2015-2-6/2:28  转载请注明出处：http://blog.csdn.net/u010019717

更全的内容请看我的游戏蛮牛地址：http://www.unitymanual.com/space-uid-18602.html 

先看一下效果：

   

区别就是一个2d一个3d.

2d就不介绍了，相对简单一些，对于3d的内容，我们先来看一看数学中的一个题和答案，这样就很容易理解程序了。

这样就好办了！    直接看下面几个脚本吧。

using UnityEngine;using System.Collections;using SunGuangDong.Math;[ExecuteInEditMode]public class DrawCircleMono : MonoBehaviour {private Vector3 m_Normal ;// Use this for initializationvoid Start () {m_Normal = new Vector3 (0, 1, 0);}void OnDrawGizmos(){Circle2d circle2 = new Circle2d(transform.position, 5);DrawCircle(ref circle2, Color.red);Vector3 center = new Vector3 (transform.position.x, transform.position.y + 0.2f, transform.position.z);Circle3d circle3 = new Circle3d(ref center,ref m_Normal, 5);DrawCircle (circle3, Color.red, 40);}protected void DrawCircle(ref Circle2d circle, Color color){int count = 40;float delta = 2f * Mathf.PI / count;Vector3 prev = circle.Eval(0);Color tempColor = Gizmos.color;Gizmos.color = color;for (int i = 1; i <= count; ++i){Vector3 curr = circle.Eval(i * delta);Gizmos.DrawLine(prev, curr);prev = curr;}Gizmos.color = tempColor;}protected void DrawCircle(Vector2 center, float radius, Color color){Circle2d circle = new Circle2d(ref center, radius);int count = 40;float delta = 2f * Mathf.PI / count;Vector3 prev = circle.Eval(0);Color tempColor = Gizmos.color;Gizmos.color = color;for (int i = 1; i <= count; ++i){Vector3 curr = circle.Eval(i * delta);Gizmos.DrawLine(prev, curr);prev = curr;}Gizmos.color = tempColor;}protected void DrawCircle(Circle3d circle, Color color, int count = 20){float delta = 2f * Mathf.PI / count;Vector3 prev = circle.Eval(0);Color tempColor = Gizmos.color;Gizmos.color = color;for (int i = 1; i <= count; ++i){Vector3 curr = circle.Eval(i * delta);Gizmos.DrawLine(prev, curr);prev = curr;}Gizmos.color = tempColor;}}

上面这个脚本在 挂到场景中的任意对象上，如Cube

namespace SunGuangDong.Math{    using System;    using System.Collections.Generic;    using System.Runtime.InteropServices;    using UnityEngine;    [StructLayout(LayoutKind.Sequential)]    public struct Circle2d    {        public Vector2 Center;        public float Radius;        public Circle2d(ref Vector2 center, float radius)        {            this.Center = center;            this.Radius = radius;        }        public Circle2d(Vector2 center, float radius)        {            this.Center = center;            this.Radius = radius;        }        public float CalcPerimeter()        {            return (6.283185f * this.Radius);        }        public float CalcArea()        {            return ((3.141593f * this.Radius) * this.Radius);        }        public Vector2 Eval(float t)        {            return new Vector2(this.Center.x + (this.Radius * Mathf.Cos(t)), this.Center.y + (this.Radius * Mathf.Sin(t)));        }        public Vector2 Eval(float t, float radius)        {            return new Vector2(this.Center.x + (radius * Mathf.Cos(t)), this.Center.y + (radius * Mathf.Sin(t)));        }        public bool Contains(ref Vector2 point)        {            Vector2 vector = point - this.Center;return (vector.magnitude <= (this.Radius * this.Radius));        }        public bool Contains(Vector2 point)        {            Vector2 vector = point - this.Center;return (vector.magnitude <= (this.Radius * this.Radius));        }        public void Include(ref Circle2d circle)        {            Vector2 vector = circle.Center - this.Center;float num = vector.magnitude;            float num2 = circle.Radius - this.Radius;            float num3 = num2 * num2;            if (num3 >= num)            {                if (num2 >= 0f)                {                    this = circle;                }            }            else            {                float num4 = Mathf.Sqrt(num);                if (num4 > 1E-05f)                {                    float num5 = (num4 + num2) / (2f * num4);                    this.Center += (Vector2) (num5 * vector);                }                this.Radius = 0.5f * ((num4 + this.Radius) + circle.Radius);            }        }        public void Include(Circle2d circle)        {            this.Include(ref circle);        }    }}

namespace SunGuangDong.Math{    using System;    using System.Runtime.InteropServices;    using UnityEngine;    [StructLayout(LayoutKind.Sequential)]    public struct Circle3d    {        public Vector3 Center;        public Vector3 Axis0;        public Vector3 Axis1;        public Vector3 Normal;        public float Radius;        public Circle3d(ref Vector3 center, ref Vector3 normal, float radius)        {            this.Center = center;            this.Normal = normal;            Vector3ex.CreateOrthonormalBasis(out this.Axis0, out this.Axis1, ref this.Normal);            this.Radius = radius;        }        public Circle3d(Vector3 center, Vector3 normal, float radius)        {            this.Center = center;            this.Normal = normal;            Vector3ex.CreateOrthonormalBasis(out this.Axis0, out this.Axis1, ref this.Normal);            this.Radius = radius;        }        public float CalcPerimeter()        {            return (6.283185f * this.Radius);        }        public float CalcArea()        {            return ((3.141593f * this.Radius) * this.Radius);        }        public Vector3 Eval(float t)        {            return (this.Center + ((Vector3) (this.Radius * ((Mathf.Cos(t) * this.Axis0) + (Mathf.Sin(t) * this.Axis1)))));        }        public Vector3 Eval(float t, float radius)        {            return (this.Center + ((Vector3) (radius * ((Mathf.Cos(t) * this.Axis0) + (Mathf.Sin(t) * this.Axis1)))));        }    }}

namespace SunGuangDong.Math{    using System;    using System.Collections.Generic;    using System.Runtime.CompilerServices;    using System.Runtime.InteropServices;    using UnityEngine;    public static class Vector3ex    {        public static readonly Vector3 Zero = new Vector3(0f, 0f, 0f);        public static void CreateOrthonormalBasis(out Vector3 u, out Vector3 v, ref Vector3 w)        {            if (Mathf.Abs(w.x) >= Mathf.Abs(w.y))            {                float num = Mathfex.InvSqrt((w.x * w.x) + (w.z * w.z));                u.x = -w.z * num;                u.y = 0f;                u.z = w.x * num;                v.x = w.y * u.z;                v.y = (w.z * u.x) - (w.x * u.z);                v.z = -w.y * u.x;            }            else            {                float num2 = Mathfex.InvSqrt((w.y * w.y) + (w.z * w.z));                u.x = 0f;                u.y = w.z * num2;                u.z = -w.y * num2;                v.x = (w.y * u.z) - (w.z * u.y);                v.y = -w.x * u.z;                v.z = w.x * u.y;            }        }}}

namespace SunGuangDong.Math{    using System;    using System.Runtime.InteropServices;    using UnityEngine;    public static class Mathfex    {        public const float Pi = 3.141593f;        public static float InvSqrt(float value)        {            if (value != 0f)            {                return (1f / Mathf.Sqrt(value));            }            return 0f;        }    }}

最后附上一些其他图片吧。