多个对象Glsl

分类：编程问答

如何解决多个对象Glsl

搜索独立绘制两个对象时，我在使用Glsl时遇到一些问题。当我搜索查看代码结果时，编译器考虑的对象是第一个纹理，而纹理是第二个纹理，此外，我不知道如何使用独立的方式设置对象的初始位置相同的着色器。 这是我的代码：

var program;
var gl;
var shaderDir; 
var baseDir;
var missileModel;
var pigModel;
var missileStr = 'model/R73-Ready.obj';
var missileTexture = 'model/R73 Texture.png';
var modelStr = 'model/mount.obj';
var modelTexture = 'model/ground_grass_3264_4062_Small.jpg';


function main() {
    
    var lastUpdateTime = (new Date).getTime();
    
    var Rx = 0.0;
    var Ry = 0.0;
    var Rz = 0.0;
    var S  = 0.5;

    utils.resizeCanvasToDisplaySize(gl.canvas);
    gl.viewport(0,gl.canvas.width,gl.canvas.height);
    gl.clearColor(0.85,1.0,0.85,1.0); 
    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
    gl.enable(gl.DEPTH_TEST);

    
    //Here we extract the position of the vertices,the normals,the indices,and the uv coordinates
    var missileVertices = missileModel.vertices;
    var missileNormals = missileModel.vertexNormals;
    var missileIndices = missileModel.indices;
    var missileTexCoords = missileModel.textures;
    
    var pigVertices = pigModel.vertices;
    var pigNormals = pigModel.vertexNormals;
    var pigIndices = pigModel.indices;
    var pigTexCoords = pigModel.textures;
    //###################################################################################
   
    var  positionAttributeLocation = gl.getAttribLocation(program,"a_position");  
    var uvAttributeLocation = gl.getAttribLocation(program,"a_uv");  
    var matrixLocation = gl.getUniformLocation(program,"matrix");  
    var textLocation = gl.getUniformLocation(program,"u_texture");

    var perspectiveMatrix = utils.MakePerspective(120,gl.canvas.width/gl.canvas.height,0.1,100.0);
    var viewMatrix = utils.MakeView(0,0.0,3.0,0.0);
    
    //drawing land
    var vao = gl.createVertexArray();
    gl.bindVertexArray(vao);

    var positionBuffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER,positionBuffer);
    gl.bufferData(gl.ARRAY_BUFFER,new Float32Array(pigVertices),gl.STATIC_DRAW);
    gl.enableVertexAttribArray(positionAttributeLocation);
    gl.vertexAttribPointer(positionAttributeLocation,3,gl.FLOAT,false,0);

    var uvBuffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER,uvBuffer);
    gl.bufferData(gl.ARRAY_BUFFER,new Float32Array(pigTexCoords),gl.STATIC_DRAW);
    gl.enableVertexAttribArray(uvAttributeLocation);
    gl.vertexAttribPointer(uvAttributeLocation,2,0);

    var indexBuffer = gl.createBuffer();
    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER,indexBuffer);
    gl.bufferData(gl.ELEMENT_ARRAY_BUFFER,new Uint16Array(pigIndices),gl.STATIC_DRAW); 

    var texture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D,texture);

    var image = new Image();
    image.src = baseDir+modelTexture;
    image.onload= function() {
    gl.bindTexture(gl.TEXTURE_2D,texture);
    gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL,true);
    gl.texImage2D(gl.TEXTURE_2D,gl.RGBA,gl.UNSIGNED_BYTE,image);
    gl.texParameteri(gl.TEXTURE_2D,gl.TEXTURE_MAG_FILTER,gl.LINEAR);
    gl.texParameteri(gl.TEXTURE_2D,gl.TEXTURE_MIN_FILTER,gl.LINEAR);
    gl.generateMipmap(gl.TEXTURE_2D);
    };
    
    
   //drawing the missile
    
    var missile = gl.createVertexArray();
    gl.bindVertexArray(missile);

    var misspositionBuffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER,misspositionBuffer);
    gl.bufferData(gl.ARRAY_BUFFER,new Float32Array(missileVertices),0);

    var missileuvBuffer = gl.createBuffer();
    gl.bindBuffer(gl.ARRAY_BUFFER,missileuvBuffer);
    gl.bufferData(gl.ARRAY_BUFFER,new Float32Array(missileTexCoords),0);

    var missindexBuffer = gl.createBuffer();
    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER,missindexBuffer);
    gl.bufferData(gl.ELEMENT_ARRAY_BUFFER,new Uint16Array(missileIndices),gl.STATIC_DRAW); 

    var misstexture = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D,misstexture);

    var missimage = new Image();
    missimage.src = baseDir+missileTexture;
    missimage.onload= function() {
    gl.bindTexture(gl.TEXTURE_2D,misstexture);
              gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL,missimage);
              gl.texParameteri(gl.TEXTURE_2D,gl.LINEAR);
              gl.texParameteri(gl.TEXTURE_2D,gl.LINEAR);
    gl.generateMipmap(gl.TEXTURE_2D);
    };
    
    
    drawScene();
    
    function animate(){
    var currentTime = (new Date).getTime();
   if(lastUpdateTime != null){
      //var deltaC = 0; //(30 * (currentTime - lastUpdateTime)) / 1000.0;
      Rx = 90;
      Ry = 90;
      Rz = 90;    
    }
    worldMatrix = utils.MakeWorld(0.0,Rx,Ry,Rz,S);
    lastUpdateTime = currentTime;               
  }
    
    function drawScene() {
    animate();

    utils.resizeCanvasToDisplaySize(gl.canvas);
    gl.clearColor(0.85,1.0);
    gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);

    var viewWorldMatrix = utils.multiplyMatrices(viewMatrix,worldMatrix);
    var projectionMatrix = utils.multiplyMatrices(perspectiveMatrix,viewWorldMatrix);

    gl.uniformMatrix4fv(matrixLocation,gl.FALSE,utils.transposeMatrix(projectionMatrix));

    gl.activeTexture(gl.TEXTURE0);
    gl.uniform1i(textLocation,misstexture);

    gl.bindVertexArray(missile);
    gl.drawElements(gl.TRIANGLES,missileIndices.length,gl.UNSIGNED_SHORT,0 );
        
    gl.activeTexture(gl.TEXTURE0);
    gl.uniform1i(textLocation,texture);

    gl.bindVertexArray(vao);
    gl.drawElements(gl.TRIANGLES,pigIndices.length,0 );


    window.requestAnimationFrame(drawScene);
  }
}

async function init(){
  
    var path = window.location.pathname;
    var page = path.split("/").pop();
    baseDir = window.location.href.replace(page,'');
    shaderDir = baseDir+"shaders/";

    var canvas = document.getElementById("c");
    gl = canvas.getContext("webgl2");
    if (!gl) {
        document.write("GL context not opened");
        return;
    }

    await utils.loadFiles([shaderDir + 'vs.glsl',shaderDir + 'fs.glsl'],function (shaderText) {
      var vertexShader = utils.createShader(gl,gl.VERTEX_SHADER,shaderText[0]);
      var fragmentShader = utils.createShader(gl,gl.FRAGMENT_SHADER,shaderText[1]);
      program = utils.createProgram(gl,vertexShader,fragmentShader); 

    });
    gl.useProgram(program);
    
    //###################################################################################
    //This loads the obj model in the pigModel variable
    var pigObjStr = await utils.get_objstr(baseDir+ missileStr);
    missileModel = new OBJ.Mesh(pigObjStr);
   
    var pigObjStr1 = await utils.get_objstr(baseDir+ modelStr);
    pigModel = new OBJ.Mesh(pigObjStr1);

    main();
}

window.onload = init;

解决方法

bindTexture将命名纹理绑定到纹理目标和当前纹理单元。当前纹理单位由activeTexture设置。
纹理单位是命名的纹理对象和纹理采样器统一之间的绑定点。采样器制服必须由纹理单位设置，而不是纹理对象名称。

您必须将纹理单位（索引）分配给纹理采样器制服，并且必须在绘制对象之前将纹理绑定到纹理单位：

gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D,misstexture);
gl.uniform1i(textLocation,0); // 0 because 'misstexture' is bound to texture unit 0  

gl.bindVertexArray(missile);
gl.drawElements(gl.TRIANGLES,missileIndices.length,gl.UNSIGNED_SHORT,0);
        
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D,texture);
gl.uniform1i(textLocation,0);  // 0 because 'texture' is bound to texture unit 0

gl.bindVertexArray(vao);
gl.drawElements(gl.TRIANGLES,pigIndices.length,0);

当然可以将纹理绑定到不同的纹理单元：

gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D,misstexture);

gl.activeTexture(gl.TEXTURE1);
gl.bindTexture(gl.TEXTURE_2D,texture);

并在绘制对象之前将纹理采样器设置为统一

gl.uniform1i(textLocation,0); // 0 because 'misstexture' is bound to texture unit 0 
gl.bindVertexArray(missile);
gl.drawElements(gl.TRIANGLES,0);

gl.uniform1i(textLocation,1);  // 1 because 'texture' is bound to texture unit 1
gl.bindVertexArray(vao);
gl.drawElements(gl.TRIANGLES,0);
,

@ Rabbid76指出，您对gl.uniform1i的纹理调用是错误的。您需要传递纹理单元索引，而不是WebGLTexture

对于位置，通常在渲染时通过均匀地将矩阵传递给着色器来设置对象的位置

for each object
  set vertex array
  gl.useProgram(whateverProgramThisObjectNeeds)
  bind textures to texture units
  set uniforms to tell shader which texture units you bound the textures to
  set uniforms for material settings (colors,etc..)
  set uniforms for matrices (projection,view,model)
  gl.drawArrays or gl.drawElements

您通常不会将位置硬编码到着色器中。设置“初始”位置不是WebGL的一部分。 WebGL只是绘制点，线和三角形。对象的位置是代码的一部分。将它们存储在数组，地图，树，场景图，游戏对象，您要化妆的东西中，然后遍历要绘制的对象，并设置一些制服以将它们绘制在正确的位置。

版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 dio@foxmail.com 举报，一经查实，本站将立刻删除。

相关推荐

导入项目后报错问题
依赖报错 idea导入项目后依赖报错，解决方案：https://blog.csdn.net/weixin_42420249/article/details/81191861 依赖版本报错：更换其他版本 无法下载依赖可参考：https://blog.csdn.net/weixin_42628809/a
idea不能识别yaml文件
使用mybatis plus常见错误
错误1：代码生成器依赖和mybatis依赖冲突 启动项目时报错如下 2021-12-03 13:33:33.927 ERROR 7228 [ main] o.s.b.d.LoggingFailureAnalysisReporter : *************************** APPL
gradle常见问题与错误
错误1：gradle项目控制台输出为乱码 # 解决方案：https://blog.csdn.net/weixin_43501566/article/details/112482302 # 在gradle-wrapper.properties 添加以下内容 org.gradle.jvmargs=-Df
Mybatis Plus传入参数0不起作用
错误还原：在查询的过程中，传入的workType为0时，该条件不起作用 <select id="xxx"> SELECT di.id, di.name, di.work_type, di.updated... <where> <if test=&qu
linux中make编译源码包失败
报错如下，gcc版本太低 ^ server.c:5346:31: 错误：‘struct redisServer’没有名为‘server_cpulist’的成员 redisSetCpuAffinity(server.server_cpulist); ^ server.c: 在函数‘hasActiveC
微服务启动错误：Command line is too long. Shorten command line for
解决方案1 1、改项目中.idea/workspace.xml配置文件，增加dynamic.classpath参数 2、搜索PropertiesComponent，添加如下 <property name="dynamic.classpath" value="tru
vue常见错误
删除根组件app.vue中的默认代码后报错：Module Error (from ./node_modules/eslint-loader/index.js): 解决方案：关闭ESlint代码检测，在项目根目录创建vue.config.js，在文件中添加 module.exports = { lin
spark常见错误
查看spark默认的python版本 [root@master day27]# pyspark /home/software/spark-2.3.4-bin-hadoop2.7/conf/spark-env.sh: line 2: /usr/local/hadoop/bin/hadoop: No s
matplotlib报错：AttributeError: module 'backend_interagg' has no attribute 'FigureCanvas'. Did you mean: 'FigureCanvasAgg'?
使用本地python环境可以成功执行 import pandas as pd import matplotlib.pyplot as plt # 设置字体 plt.rcParams['font.sans-serif'] = ['SimHei'] # 能正确显示负号 p
gitlab登录失败，报错：This challenge page was accidentally cached by an intermediary and is no longer available.
设置时间 控制面板
后端开发常见错误
错误1：Request method ‘DELETE‘ not supported 错误还原：controller层有一个接口，访问该接口时报错：Request method ‘DELETE‘ not supported 错误原因：没有接收到前端传入的参数，修改为如下 参考 错误2：cannot r
docker常见错误
错误1：启动docker镜像时报错：Error response from daemon: driver failed programming external connectivity on endpoint quirky_allen 解决方法：重启docker -> systemctl r
idea常见错误
错误1：private field ‘xxx‘ is never assigned 按Altʾnter快捷键，选择第2项 参考：https://blog.csdn.net/shi_hong_fei_hei/article/details/88814070 错误2：启动时报错，不能找到主启动类 #
pip安装依赖失败
报错如下，通过源不能下载，最后警告pip需升级版本 Requirement already satisfied: pip in c:\users\ychen\appdata\local\programs\python\python310\lib\site-packages (22.0.4) Coll
maven常见错误
错误1：maven打包报错 错误还原：使用maven打包项目时报错如下 [ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:3.2.0:resources (default-resources)
cloud项目中常见错误
错误1：服务调用时报错 服务消费者模块assess通过openFeign调用服务提供者模块hires 如下为服务提供者模块hires的控制层接口 @RestController @RequestMapping("/hires") public class FeignControl
springboot常见错误
错误1：运行项目后报如下错误 解决方案 报错2：Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project sb 解决方案：在pom.
springmvc拦截器中使用redisTemplate报空指针异常
参考 错误原因 过滤器或拦截器在生效时，redisTemplate还没有注入 解决方案：在注入容器时就生效 @Component //项目运行时就注入Spring容器 public class RedisBean { @Resource private RedisTemplate<String
vite报错：npm ERR! command C:WINDOWSsystem32cmd.exe /d /s /c C:UsersychenAppDataLocalTempnpx-dde1c848.cmd
使用vite构建项目报错 C:\Users\ychen\work>npm init @vitejs/app @vitejs/create-app is deprecated, use npm init vite instead C:\Users\ychen\AppData\Local\npm-
pythonJavaScriptjavaHTMLPHPreactjsC#AndroidCSSNode.jssqlrpython-3.xMysqLjQueryc++pandasFlutterangularIOSdjangolinuxswifttypescript路由器JSON路由器设置无线路由器h3c华三华三路由器设置华三路由器电脑软件教程arraysdocker软件图文教程Cvue.jslaravelspring-boot