Unity3D笔记十八 GL图像库

谁践踏了优雅 2021-12-12 11:13 320阅读 0赞

1、绘制2D图像的时需要使用GL.LoadOrtho()方法来将图形映射到平面中。

2、所有绘制相关的内容都要写在OnPostRender()方法中。

3、有关GL图像库的脚本需要绑定到Hierarchy视图中Camera上，否则无法显示绘制的图像。

4、在GL图像库的平面坐标系中，每个点的横坐标和纵坐标都应当是0与1之间的浮点数，而真实的像素坐标需要根据这个浮点数来计算

一、绘制线

别忘了添加物理材质public Material material;

using UnityEngine;
    using System.Collections;
    
    /// <summary>
    /// GL 图像库
    /// 1、GL图像库是底层的图像库，主要功能是使用程序来绘制常见的2D与3D几何图形。这些图形
    /// 具有一定的特殊性，它们不属于3D网格图形，只会以面的形式渲染
    /// 
    /// 2、绘制2D图像时，需要使用GL.LoadOrtho()方法来将图形映射在平面中，绘制的是3D图形，就无须使用此方法
    /// 
    /// 3、使用GL图像库时，需要将所有绘制相关的内容写在OnPostRender()方法中
    /// </summary>
    public class _7_5 : MonoBehaviour
    {
        /// <summary>
        /// 绘制线段的材质
        /// </summary>
        public Material material;
    
    
        private void OnPostRender()
        {
            if (!material)
            {
                Debug.Log("请给材质资源赋值");
                return;
            }
            material.SetPass(0);//设置该材质通道，0为默认值
            GL.LoadOrtho();//设置绘制2D图像
            GL.Begin(GL.LINES);//表示开始绘制，绘制类型为线段
            DrawLine(0, 0, 200, 100);//绘制线段0
            DrawLine(0, 50, 200, 150);//绘制线段1
            DrawLine(0, 100, 200, 200);//绘制线段2
            GL.End();//结束绘制
        }
    
        private void DrawLine(float x1, float y1, float x2, float y2)
        {
            //绘制线段，需要将屏幕中某个点的像素坐标除以屏幕宽或高
            GL.Vertex(new Vector3(x1 / Screen.width, y1 / Screen.height, 0));// ['vɜ:teks] n. 最高点；顶点；<数>（三角形、圆锥体等与底相对的）顶；
            GL.Vertex(new Vector3(x2 / Screen.width, y2 / Screen.height, 0));
        }
    
        // Use this for initialization
        void Start()
        {
    
        }
    
        // Update is called once per frame
        void Update()
        {
    
        }
    }

![270804465949331.jpg][]

二、绘制曲线

using UnityEngine;
    using System.Collections;
    using System.Collections.Generic;
    /// <summary>
    /// 绘制曲线
    /// </summary>
    public class _7_5_1 : MonoBehaviour
    {
        /// <summary>
        /// 绘制线段材质
        /// </summary>
        public Material material;
    
        private List<Vector3> lineInfo;
        // Use this for initialization
        void Start()
        {
            //初始化鼠标线段链表
            lineInfo = new List<Vector3>();
        }
    
        // Update is called once per frame
        void Update()
        {
            //将每次鼠标改变的位置存储进链表
            lineInfo.Add(Input.mousePosition);
        }
    
        private void OnGUI()
        {
            GUILayout.Label("当前鼠标x轴位置" + Input.mousePosition.x);
            GUILayout.Label("当前鼠标y轴位置" + Input.mousePosition.y);
        }
    
        private void OnPostRender()
        {
            if (!material)
            {
                Debug.LogError("请给材质资源赋值");
                return;
            }
            material.SetPass(0);//设置该材质通道，0为默认值
            GL.LoadOrtho();//设置绘制2D图像
            GL.Begin(GL.LINES);//表示开始绘制，绘制类型为线段 
            for (int i = 0; i < lineInfo.Count - 1; i++)
            {
                Vector3 start = lineInfo[i];
                Vector3 end = lineInfo[i + 1];
                //绘制线段
                DrawLine(start.x, start.y, end.x, end.y);
            }
            GL.End();
        }
        /// <summary>
        /// 绘制线段
        /// </summary>
        /// <param name="x1"></param>
        /// <param name="y1"></param>
        /// <param name="x2"></param>
        /// <param name="y2"></param>
        private void DrawLine(float x1, float y1, float x2, float y2)
        {
            //绘制线段，需要将屏幕中某个点的像素坐标点除以屏幕宽或高
            GL.Vertex(new Vector3(x1 / Screen.width, y1 / Screen.height, 0));// [ˈvɜ:ˌteks] 最高点；顶点
            GL.Vertex(new Vector3(x2 / Screen.width, y2 / Screen.height, 0));
        }
    }

![271035513289605.jpg][]

三、绘制四边形

绘制四边形，需要使用GL.Begin(GL.QUADS)方法

using UnityEngine;
    using System.Collections;
    
    public class _7_5_3 : MonoBehaviour
    {
        /// <summary>
        /// 可用材质0
        /// </summary>
        public Material material0;
        /// <summary>
        /// 可用材质1
        /// </summary>
        public Material material1;
        /// <summary>
        /// 可用材质2
        /// </summary>
        public Material material2;
    
        private void OnPostRender()
        {
            //绘制正四边形
            DrawRect(100, 100, 100, 100, material0);
            DrawRect(250, 100, 100, 100, material1);
            //绘制无规则四边形
            DrawQuads(15, 5, 10, 115, 95, 110, 90, 10, material2);
        }
    
        /// <summary>
        /// 绘制正四边形
        /// </summary>
        /// <param name="x">x轴起始坐标</param>
        /// <param name="y">y轴起始坐标</param>
        /// <param name="width">正四边形的宽</param>
        /// <param name="height">正四边形的高</param>
        /// <param name="material"></param>
        private void DrawRect(float x, float y, float width, float height, Material material)
        {
            GL.PushMatrix();   // [ˈmeɪtrɪks]n. <数>矩阵；模型；基质；母体，子宫
            material.SetPass(0);
            GL.LoadOrtho();
            GL.Begin(GL.QUADS);//绘制类型为四边形
            GL.Vertex3(x / Screen.width, y / Screen.height, 0);//['vɜ:teks] n. 最高点；顶点
            GL.Vertex3(x / Screen.width, (y + height) / Screen.height, 0);
            GL.Vertex3((x + width) / Screen.width, (y + height) / Screen.height, 0);
            GL.Vertex3((x + width) / Screen.width, y / Screen.height, 0);
            GL.End();
            GL.PopMatrix();
        }
    
    
        /// <summary>
        /// 绘制无规则的四边形
        /// </summary>
        /// <param name="x1">起始点1的横坐标</param>
        /// <param name="y1">起始点1的纵坐标</param>
        /// <param name="x2">起始点2的横坐标</param>
        /// <param name="y2">起始点2的纵坐标</param>
        /// <param name="x3">起始点3的横坐标</param>
        /// <param name="y3">起始点3的纵坐标</param>
        /// <param name="x3">起始点4的横坐标</param>
        /// <param name="y3">起始点4的纵坐标</param>
        /// <param name="material">material</param>
        private void DrawQuads(float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4, Material material)
        {
            GL.PushMatrix();
            material.SetPass(0);
            GL.LoadOrtho();
            GL.Begin(GL.QUADS);//绘制类型为四边形
            GL.Vertex3(x1 / Screen.width, y1 / Screen.height, 0);
            GL.Vertex3(x2 / Screen.width, y2 / Screen.height, 0);
            GL.Vertex3(x3 / Screen.width, y3 / Screen.height, 0);
            GL.Vertex3(x4 / Screen.width, y4 / Screen.height, 0);
            GL.End();
            GL.PopMatrix();
        }
    
        // Use this for initialization
        void Start()
        {
    
        }
    
        // Update is called once per frame
        void Update()
        {
    
        }
    }

![271304497811658.jpg][]

四、绘制三角形

使用GL.Begin(GL.TRIANGLE)方法,参数为三角形的类型。**\[****'traɪæŋɡl****\]****n.** 三角形；三人一组；三角铁；三角板

using UnityEngine;
    using System.Collections;
    /// <summary>
    /// 绘制三角形
    /// 使用GL.Vertex3()方法确定三角形三个顶点的位置，并将绘制三角形
    ///的所有方法封装在DrawTriangle()方法中，最后使用GL.End()方法将三角形显示在屏幕中。
    ///需要说明的是，在调用DrawTriangle()方法时，需要将三个点的坐标与材质传入该方法。
    /// </summary>
    public class _7_5_4 : MonoBehaviour
    {
        /// <summary>
        /// 材质
        /// </summary>
        public Material material;
    
    
        private void OnPostRender()
        {
            //绘制三角形
            DrawTriangle(100, 0, 100, 200, 200, 100, material);
        }
        /// <summary>
        ///绘制三角形
        ///Triangle n. 三角形；三人一组['traɪæŋɡl]
        /// </summary>
        private void DrawTriangle(float x1, float y1, float x2, float y2, float x3, float y3, Material material)
        {
            material.SetPass(0);
            GL.LoadOrtho();
            GL.Begin(GL.TRIANGLES);//绘制三角形
            GL.Vertex3(x1 / Screen.width, y1 / Screen.height, 0);
            GL.Vertex3(x2 / Screen.width, y2 / Screen.height, 0);
            GL.Vertex3(x3 / Screen.width, y3 / Screen.height, 0);
            GL.End();
        }
    
        // Use this for initialization
        void Start()
        {
    
        }
    
        // Update is called once per frame
        void Update()
        {
    
        }
    }

![271316525473949.jpg][]

五、绘制3D几何图形

using UnityEngine;
    using System.Collections;
    
    /// <summary>
    /// 绘制 3D几何图形
    /// </summary>
    public class _7_5_5 : MonoBehaviour
    {
    
        #region 材质
        public Material material0;
        public Material material1;
        public Material material2;
        #endregion
    
        private void OnPostRender()
        {
            //绘制正四边形
            DrawRect(100, 100, 100, 100, material0);
            DrawRect(250, 100, 100, 100, material1);
            //绘制无规则四边形
            DrawQuads(15, 5, 10, 115, 95, 110, 90, 10, material2);
        }
        /// <summary>
        /// 绘制正四边形
        /// </summary>
        /// <param name="x">x轴起始坐标</param>
        /// <param name="y">y轴起始坐标</param>
        /// <param name="width">正四边形的宽</param>
        /// <param name="height">正四边形的高</param>
        /// <param name="material">material</param>
        private void DrawRect(float x, float y, float width, float height, Material material)
        {
            GL.PushMatrix();
            material.SetPass(0);
            GL.Begin(GL.QUADS);//四边形
            GL.Vertex3(x / Screen.width, y / Screen.height, 0);
            GL.Vertex3(x / Screen.width, (y + height) / Screen.height, 0);
            GL.Vertex3((x + width) / Screen.width, (y + height) / Screen.height, 0);
            GL.Vertex3(x / Screen.width, (y + height) / Screen.height, 0);
            GL.End();
            GL.PopMatrix();
        }
    
        /// <summary>
        /// 绘制无规则四边形
        /// </summary>
        /// <param name="x1">起始点1的横坐标</param>
        /// <param name="y1">起始点1的纵坐标</param>
        /// <param name="x2">起始点2的横坐标</param>
        /// <param name="y2">起始点2的纵坐标</param>
        /// <param name="x3">起始点3的横坐标</param>
        /// <param name="y3">起始点3的纵坐标</param>
        /// <param name="x4">起始点4的横坐标</param>
        /// <param name="y4">起始点4的纵坐标</param>
        /// <param name="material">material</param>
        private void DrawQuads(float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4,
                               Material material)
        {
            GL.PushMatrix();//[ˈmeɪtrɪks] n. <数>矩阵；模型；基质；母体，子宫
            material.SetPass(0);
            GL.Begin(GL.QUADS);
            GL.Vertex3(x1 / Screen.width, y1 / Screen.height, 0);
            GL.Vertex3(x2 / Screen.width, y2 / Screen.height, 0);
            GL.Vertex3(x3 / Screen.width, y3 / Screen.height, 0);
            GL.Vertex3(x4 / Screen.width, y4 / Screen.height, 0);
            GL.End();
            GL.PopMatrix();
        }
    
        // Use this for initialization
        void Start()
        {
    
        }
    
        // Update is called once per frame
        void Update()
        {
    
        }
    }

六、绘制线

任何一个模型都由若干网格面组成，而每一个面又由若干个三角形组成，也就是说，模型是由若干个三角形面组成的

using UnityEngine;
    using System.Collections;
    
    public class _7_5_7 : MonoBehaviour
    {
    
    
        #region 构成三角形1的三个顶点位置
        Vector3 v0 = new Vector3(5, 0, 0);
    
        Vector3 v1 = new Vector3(0, 5, 0);
    
        Vector3 v2 = new Vector3(0, 0, 5);
        #endregion
        //构成三角形2的三个顶点位置
        Vector3 v3 = new Vector3(-5, 0, 0);
        Vector3 v4 = new Vector3(0, -5, 0);
        Vector3 v5 = new Vector3(0, 0, -5);
        //构成三角形1的贴图比例
        Vector2 u0 = new Vector2(0, 0);
        Vector2 u1 = new Vector2(0, 5);
        Vector2 u2 = new Vector2(5, 5);
        //构成三角形2的贴图比例
        Vector2 u3 = new Vector2(0, 0);
        Vector2 u4 = new Vector2(0, 1);
        Vector2 u5 = new Vector2(1, 1);
    
        // Use this for initialization
        void Start()
        {
            //得到网格渲染器对象
            MeshFilter meshFilter = (MeshFilter)GameObject.Find("face").GetComponent(typeof(MeshFilter));
            Mesh mesh = meshFilter.mesh; //通过渲染器对象得到网格对象
            mesh.vertices = new Vector3[] { v0, v1, v2, v3, v4, v5 };// n. 至高点，头顶；最高点( vertex的名词复数 )；[ˈvə:tisi:z] 
            mesh.uv = new Vector2[] { v0, v1, v2, v3, v4, v5 };//设置三角形面上的贴图比例
            mesh.triangles = new int[] { 0, 1, 2, 3, 4, 5 };//[t'raɪæŋɡlz] n. 三角形( triangle的名词复数 )；
        }
    
        // Update is called once per frame
        void Update()
        {
    
        }
    }

转载于:https://www.cnblogs.com/PEPE/p/3534562.html

[270804465949331.jpg]: /images/20211211/5e36848def2841f0bd77e02e3264716f.png
[271035513289605.jpg]: /images/20211211/067be25e5cb2499fbde82b86685629e4.png
[271304497811658.jpg]: /images/20211211/a568f9e932d64037a32cd097af480084.png
[271316525473949.jpg]: /images/20211211/408465a15b5043d9ba2d00f92f01c5d0.png