在WebGL中绘制立方体
我不确定这段代码中的问题是什么,但当我尝试绘制远离摄影机视图的立方体线条(最后4行)时,对象会消失。然而,我能画出立方体的8条边线在WebGL中绘制立方体,webgl,Webgl,我不确定这段代码中的问题是什么,但当我尝试绘制远离摄影机视图的立方体线条(最后4行)时,对象会消失。然而,我能画出立方体的8条边线 vec4(-0.5, -0.5, 1.5, 1.0),//1 vec4(-0.5, 0.5, 1.5, 1.0),//2 vec4(-0.5, -0.5, 1.5, 1.0),//1 vec4(0.5, -0.5, 1.5, 1.0),//4 vec4(-0.5, -0.5
vec4(-0.5, -0.5, 1.5, 1.0),//1
vec4(-0.5, 0.5, 1.5, 1.0),//2
vec4(-0.5, -0.5, 1.5, 1.0),//1
vec4(0.5, -0.5, 1.5, 1.0),//4
vec4(-0.5, -0.5, 1.5, 1.0),//1
vec4(-0.5, -0.5, 0.5, 1.0),//5
vec4(-0.5, 0.5, 1.5, 1.0),//2
vec4(0.5, 0.5, 1.5, 1.0),//3
vec4(-0.5, 0.5, 1.5, 1.0),//2
vec4(-0.5, 0.5, 0.5, 1.0),//6
vec4(0.5, 0.5, 1.5, 1.0),//3
vec4(0.5, -0.5, 1.5, 1.0),//4
vec4(0.5, 0.5, 1.5, 1.0),//3
vec4(0.5, 0.5, 0.5, 1.0),//7
vec4(0.5, -0.5, 1.5, 1.0),//4
vec4( 0.5, -0.5, 0.5, 1.0) //8
/*
vec4(-0.5, -0.5, 0.5, 1.0),//5
vec4(-0.5, 0.5, 0.5, 1.0),//6
vec4(-0.5, -0.5, 0.5, 1.0),//5
vec4( 0.5, -0.5, 0.5, 1.0) //8
vec4(-0.5, 0.5, 0.5, 1.0),//6
vec4(0.5, 0.5, 0.5, 1.0),//7
vec4(0.5, 0.5, 0.5, 1.0),//7
vec4( 0.5, -0.5, 0.5, 1.0) //8
*/
立方体的线(点)如下所示。只有前8行(16点)显示,但其余4行(8点)我无法添加到多维数据集
vec4(-0.5, -0.5, 1.5, 1.0),//1
vec4(-0.5, 0.5, 1.5, 1.0),//2
vec4(-0.5, -0.5, 1.5, 1.0),//1
vec4(0.5, -0.5, 1.5, 1.0),//4
vec4(-0.5, -0.5, 1.5, 1.0),//1
vec4(-0.5, -0.5, 0.5, 1.0),//5
vec4(-0.5, 0.5, 1.5, 1.0),//2
vec4(0.5, 0.5, 1.5, 1.0),//3
vec4(-0.5, 0.5, 1.5, 1.0),//2
vec4(-0.5, 0.5, 0.5, 1.0),//6
vec4(0.5, 0.5, 1.5, 1.0),//3
vec4(0.5, -0.5, 1.5, 1.0),//4
vec4(0.5, 0.5, 1.5, 1.0),//3
vec4(0.5, 0.5, 0.5, 1.0),//7
vec4(0.5, -0.5, 1.5, 1.0),//4
vec4( 0.5, -0.5, 0.5, 1.0) //8
/*
vec4(-0.5, -0.5, 0.5, 1.0),//5
vec4(-0.5, 0.5, 0.5, 1.0),//6
vec4(-0.5, -0.5, 0.5, 1.0),//5
vec4( 0.5, -0.5, 0.5, 1.0) //8
vec4(-0.5, 0.5, 0.5, 1.0),//6
vec4(0.5, 0.5, 0.5, 1.0),//7
vec4(0.5, 0.5, 0.5, 1.0),//7
vec4( 0.5, -0.5, 0.5, 1.0) //8
*/
非常感谢您的帮助
代码如下:
<script id="vertex-shader" type="x-shader/x-vertex">
attribute vec4 vPosition;
attribute vec4 vColor;
varying vec4 fColor;
uniform mat4 modelViewMatrix;
uniform mat4 projectionMatrix;
void main()
{
gl_Position = projectionMatrix*modelViewMatrix*vPosition;
fColor = vColor;
}
</script>
<script id="fragment-shader" type="x-shader/x-fragment">
precision mediump float;
varying vec4 fColor;
void
main()
{
gl_FragColor = fColor;
}
</script>
var canvas;
var gl;
var NumVertices = 24;
var vertices = [
vec4(-0.5, -0.5, 1.5, 1.0),//1
vec4(-0.5, 0.5, 1.5, 1.0),//2
vec4(-0.5, -0.5, 1.5, 1.0),//1
vec4(0.5, -0.5, 1.5, 1.0),//4
vec4(-0.5, -0.5, 1.5, 1.0),//1
vec4(-0.5, -0.5, 0.5, 1.0),//5
vec4(-0.5, 0.5, 1.5, 1.0),//2
vec4(0.5, 0.5, 1.5, 1.0),//3
vec4(-0.5, 0.5, 1.5, 1.0),//2
vec4(-0.5, 0.5, 0.5, 1.0),//6
vec4(0.5, 0.5, 1.5, 1.0),//3
vec4(0.5, -0.5, 1.5, 1.0),//4
vec4(0.5, 0.5, 1.5, 1.0),//3
vec4(0.5, 0.5, 0.5, 1.0),//7
vec4(0.5, -0.5, 1.5, 1.0),//4
vec4( 0.5, -0.5, 0.5, 1.0) //8
/*
vec4(-0.5, -0.5, 0.5, 1.0),//5
vec4(-0.5, 0.5, 0.5, 1.0),//6
vec4(-0.5, -0.5, 0.5, 1.0),//5
vec4( 0.5, -0.5, 0.5, 1.0) //8
vec4(-0.5, 0.5, 0.5, 1.0),//6
vec4(0.5, 0.5, 0.5, 1.0),//7
vec4(0.5, 0.5, 0.5, 1.0),//7
vec4( 0.5, -0.5, 0.5, 1.0) //8
*/
];
var vertexColors = [
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
/*
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
vec4( 1.0, 0.0, 0.0, 1.0 ), // red
*/
];
var near = 0.3;
var far = 10.0;
var radius = 4.0;
var theta = 0.0;
var phi = 0.0;
var dr = 5.0 * Math.PI/180.0;
var fovy = 90.0; // Field-of-view in Y direction angle (in degrees)
var aspect; // Viewport aspect ratio
var modelViewMatrix, projectionMatrix;
var modelViewMatrixLoc, projectionMatrixLoc;
var eye;
const at = vec3(0.0, 0.0, 0.0);
const up = vec3(0.0, 1.0, 0.0);
var program;
var program_originline;
var cBuffer;
var vColor;
var vBuffer;
var vPosition;
var l_vBuffer;
var l_vPosition;
var l_cBuffer;
var l_vColor;
window.onload = function init() {
canvas = document.getElementById( "gl-canvas" );
gl = WebGLUtils.setupWebGL( canvas );
if ( !gl ) { alert( "WebGL isn't available" ); }
gl.viewport( 0, 0, canvas.width, canvas.height );
aspect = canvas.width/canvas.height;
gl.clearColor( 0.0, 0.0, 0.0, 1.0 );
gl.enable(gl.DEPTH_TEST);
// Load shaders and initialize attribute buffers
program_originline = initShaders( gl, "vertex-shader", "fragment-shader" );
program = initShaders( gl, "vertex-shader", "fragment-shader" );
//CUBE Buffers
cBuffer = gl.createBuffer();
gl.bindBuffer( gl.ARRAY_BUFFER, cBuffer );
//gl.bufferData( gl.ARRAY_BUFFER, flatten(colorsArray), gl.STATIC_DRAW );
gl.bufferData( gl.ARRAY_BUFFER, flatten(vertexColors), gl.STATIC_DRAW );
vColor = gl.getAttribLocation( program, "vColor" );
//gl.vertexAttribPointer( vColor, 4, gl.FLOAT, false, 0, 0 );
//gl.enableVertexAttribArray( vColor);
vBuffer = gl.createBuffer();
gl.bindBuffer( gl.ARRAY_BUFFER, vBuffer );
//gl.bufferData( gl.ARRAY_BUFFER, flatten(pointsArray), gl.STATIC_DRAW );
gl.bufferData( gl.ARRAY_BUFFER, flatten(vertices), gl.STATIC_DRAW );
vPosition = gl.getAttribLocation( program, "vPosition" );
//Static Line
var l_vertices = [
vec4(0.0, 0.0, 0.0, 1.0),
vec4(5.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 5.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 5.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(-5.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, -5.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, -5.0, 1.0),
];
// Load the data into the GPU
l_vBuffer = gl.createBuffer();
gl.bindBuffer( gl.ARRAY_BUFFER, l_vBuffer );
gl.bufferData( gl.ARRAY_BUFFER, flatten(l_vertices), gl.STATIC_DRAW );
// Associate out shader variables with our data buffer
l_vPosition = gl.getAttribLocation( program_originline, "vPosition" );
var l_colors = [
vec4(1.0, 1.0, 0.0, 1.0),
vec4(1.0, 1.0, 0.0, 1.0),
vec4(1.0, 1.0, 0.0, 1.0),
vec4(1.0, 1.0, 0.0, 1.0),
vec4(1.0, 1.0, 0.0, 1.0),
vec4(1.0, 1.0, 0.0, 1.0),
vec4(0.0, 0.0, 1.0, 1.0),
vec4(0.0, 0.0, 1.0, 1.0),
vec4(0.0, 0.0, 1.0, 1.0),
vec4(0.0, 0.0, 1.0, 1.0),
vec4(0.0, 0.0, 1.0, 1.0),
vec4(0.0, 0.0, 1.0, 1.0),
];
l_cBuffer = gl.createBuffer();
gl.bindBuffer( gl.ARRAY_BUFFER, l_cBuffer );
gl.bufferData( gl.ARRAY_BUFFER, flatten(l_colors), gl.STATIC_DRAW );
l_vColor = gl.getAttribLocation( program_originline, "vColor" );
// buttons for viewing parameters
document.getElementById("Button1").onclick = function(){near *= 1.1; far *= 1.1;};
document.getElementById("Button2").onclick = function(){near *= 0.9; far *= 0.9;};
document.getElementById("Button3").onclick = function(){radius *= 2.0;};
document.getElementById("Button4").onclick = function(){radius *= 0.5;};
document.getElementById("Button5").onclick = function(){theta += dr;};
document.getElementById("Button6").onclick = function(){theta -= dr;};
document.getElementById("Button7").onclick = function(){phi += dr;};
document.getElementById("Button8").onclick = function(){phi -= dr;};
render();
}
var render = function(){
gl.clear( gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
//LINE PROGRAM
gl.useProgram( program_originline );
gl.enableVertexAttribArray( l_vPosition );
gl.bindBuffer( gl.ARRAY_BUFFER, l_vBuffer );
gl.vertexAttribPointer( l_vPosition, 4, gl.FLOAT, false, 0, 0 );
gl.enableVertexAttribArray( l_vColor );
gl.bindBuffer( gl.ARRAY_BUFFER, l_cBuffer );
gl.vertexAttribPointer( l_vColor, 4, gl.FLOAT, false, 0, 0 );
gl.drawArrays( gl.LINES, 0, 12);
modelViewMatrixLoc = gl.getUniformLocation( program_originline, "modelViewMatrix" );
projectionMatrixLoc = gl.getUniformLocation( program_originline, "projectionMatrix" );
eye = vec3(radius*Math.sin(theta)*Math.cos(phi),
radius*Math.sin(theta)*Math.sin(phi), radius*Math.cos(theta));
modelViewMatrix = lookAt(eye, at , up);
projectionMatrix = perspective(fovy, aspect, near, far);
gl.uniformMatrix4fv( modelViewMatrixLoc, false, flatten(modelViewMatrix) );
gl.uniformMatrix4fv( projectionMatrixLoc, false, flatten(projectionMatrix) );
//CUBE PROGRAM
gl.useProgram( program );
gl.enableVertexAttribArray( vPosition );
gl.bindBuffer( gl.ARRAY_BUFFER, vBuffer );
gl.vertexAttribPointer( vPosition, 4, gl.FLOAT, false, 0, 0 );
gl.enableVertexAttribArray( vColor);
gl.bindBuffer( gl.ARRAY_BUFFER, cBuffer );
gl.vertexAttribPointer( vColor, 4, gl.FLOAT, false, 0, 0 );
gl.drawArrays( gl.LINES, 0, 18 );
modelViewMatrixLoc = gl.getUniformLocation( program, "modelViewMatrix" );
projectionMatrixLoc = gl.getUniformLocation( program, "projectionMatrix" );
eye = vec3(radius*Math.sin(theta)*Math.cos(phi),radius*Math.sin(theta)*Math.sin(phi), radius*Math.cos(theta));
modelViewMatrix = lookAt(eye, at , up);
projectionMatrix = perspective(fovy, aspect, near, far);
gl.uniformMatrix4fv( modelViewMatrixLoc, false, flatten(modelViewMatrix) );
gl.uniformMatrix4fv( projectionMatrixLoc, false, flatten(projectionMatrix) );
requestAnimFrame(render);
}
属性向量4位置;
属性向量4彩色;
可变的vec4颜色;
统一mat4模型视图矩阵;
均匀mat4投影矩阵;
void main()
{
gl_位置=投影矩阵*模型视图矩阵*位置;
fColor=vColor;
}
精密中泵浮子;
可变的vec4颜色;
无效的
main()
{
gl_FragColor=fColor;
}
var帆布;
var-gl;
var NumVertices=24;
变量顶点=[
vec4(-0.5,-0.5,1.5,1.0),//1
vec4(-0.5,0.5,1.5,1.0),//2
vec4(-0.5,-0.5,1.5,1.0),//1
vec4(0.5,-0.5,1.5,1.0),//4
vec4(-0.5,-0.5,1.5,1.0),//1
vec4(-0.5,-0.5,0.5,1.0),//5
vec4(-0.5,0.5,1.5,1.0),//2
vec4(0.5,0.5,1.5,1.0),//3
vec4(-0.5,0.5,1.5,1.0),//2
vec4(-0.5,0.5,0.5,1.0),//6
vec4(0.5,0.5,1.5,1.0),//3
vec4(0.5,-0.5,1.5,1.0),//4
vec4(0.5,0.5,1.5,1.0),//3
vec4(0.5,0.5,0.5,1.0),//7
vec4(0.5,-0.5,1.5,1.0),//4
vec4(0.5,-0.5,0.5,1.0)//8
/*
vec4(-0.5,-0.5,0.5,1.0),//5
vec4(-0.5,0.5,0.5,1.0),//6
vec4(-0.5,-0.5,0.5,1.0),//5
vec4(0.5,-0.5,0.5,1.0)//8
vec4(-0.5,0.5,0.5,1.0),//6
vec4(0.5,0.5,0.5,1.0),//7
vec4(0.5,0.5,0.5,1.0),//7
vec4(0.5,-0.5,0.5,1.0)//8
*/
];
可变顶点颜色=[
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
/*
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
vec4(1.0,0.0,0.0,1.0),//红色
*/
];
var近=0.3;
var-far=10.0;
var半径=4.0;
varθ=0.0;
var phi=0.0;
var-dr=5.0*Math.PI/180.0;
变量fovy=90.0;//Y方向的视野角度(以度为单位)
变量方面;//视口纵横比
var modelViewMatrix,projectionMatrix;
var modelViewMatrixLoc,projectionMatrixLoc;
外翻眼;
常数at=vec3(0.0,0.0,0.0);
常数up=vec3(0.0,1.0,0.0);
var程序;
var程序的原始版本;
var cBuffer;
色差;
var vBuffer;
变量位置;
var l_vBuffer;
变量lvposition;
var l_cBuffer;
var l_vColor;
window.onload=函数init(){
画布=document.getElementById(“gl画布”);
gl=WebGLUtils.setupWebGL(画布);
如果(!gl){alert(“WebGL不可用”);}
总图视口(0,0,canvas.width,canvas.height);
纵横比=canvas.width/canvas.height;
gl.clearColor(0.0,0.0,0.0,1.0);
总帐启用(总帐深度测试);
//加载着色器并初始化属性缓冲区
program_originline=initShaders(gl,“顶点着色器”、“片段着色器”);
程序=初始着色器(gl,“顶点着色器”、“片段着色器”);
//多维数据集缓冲区
cBuffer=gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER,cBuffer);
//gl.bufferData(gl.ARRAY\u BUFFER、展平(colorsArray)、gl.STATIC\u DRAW);
gl.bufferData(gl.ARRAY\u BUFFER,展平(顶点颜色),gl.STATIC\u DRAW);
vColor=gl.getAttribLocation(程序,“vColor”);
//gl.VertexAttribute指针(vColor,4,gl.FLOAT,false,0,0);
//gl.EnableVertexAttributeArray(vColor);
vBuffer=gl.createBuffer();
gl.bindBuffer(gl.ARRAY\u BUFFER,vBuffer);
//gl.bufferData(gl.ARRAY\u BUFFER、展平(pointsArray)、gl.STATIC\u DRAW);
gl.bufferData(gl.ARRAY\u BUFFER、展平(顶点)、gl.STATIC\u DRAW);
vPosition=gl.getAttriblLocation(程序,“vPosition”);
//静态线
var l_顶点=[
vec4(0.0,0.0,0.0,1.0),
vec4(5.0,0.0,0.0,1.0),
vec4(0.0,0.0,0.0,1.0),
vec4(0.0,5.0,0.0,1.0),
vec4(0.0,0.0,0.0,1.0),
vec4(0.0,0.0,5.0,1.0),
vec4(0.0,0.0,0.0,1.0),
vec4(-5.0,0.0,0.0,1.0),
vec4(0.0,0.0,0.0,1.0),
vec4(0.0,-5.0,0.0,1.0),
vec4(0.0,0.0,0.0,1.0),
vec4(0.0,0.0,-5.0,1.0),
];
//将数据加载到GPU中
l_vBuffer=gl.createBuffer();
gl.bindBuffer(gl.ARRAY\u BUFFER,l\u vBuffer);
gl.bufferData(gl.ARRAY\u BUFFER、展平(l\u顶点)、gl.STATIC\u DRAW);
//将着色器变量与数据缓冲区相关联
l_vPosition=gl.getAttriblosition(程序初始,“vPosition”);
变量l_颜色=[
vec4(1.0,1.0,0.0,1.0),
vec4(1.0,