Question

在THREEJS中创建ShaderMaterial时，传递片段和顶点着色器：

new THREE.ShaderMaterial({
    uniforms: {
        time: { value: 1.0 },
        resolution: { value: new THREE.Vector2() }
    },
    attributes: {
        vertexOpacity: { value: [] }
    },
    vertexShader: document.getElementById('v-shader').textContent,
    fragmentShader: document.getElementById('f-shader').textContent
});

但我正在使用一个使用双遍顶点着色器的教程：

//Horizontal
attribute vec4 a_position;
attribute vec2 a_texCoord;

varying vec2 v_texCoord;
varying vec2 v_blurTexCoords[14];

void main()
{
    gl_Position = a_position;
    v_texCoord = a_texCoord;
    v_blurTexCoords[ 0] = v_texCoord + vec2(-0.028, 0.0);
    v_blurTexCoords[ 1] = v_texCoord + vec2(-0.024, 0.0);
    v_blurTexCoords[ 2] = v_texCoord + vec2(-0.020, 0.0);
    v_blurTexCoords[ 3] = v_texCoord + vec2(-0.016, 0.0);
    v_blurTexCoords[ 4] = v_texCoord + vec2(-0.012, 0.0);
    v_blurTexCoords[ 5] = v_texCoord + vec2(-0.008, 0.0);
    v_blurTexCoords[ 6] = v_texCoord + vec2(-0.004, 0.0);
    v_blurTexCoords[ 7] = v_texCoord + vec2( 0.004, 0.0);
    v_blurTexCoords[ 8] = v_texCoord + vec2( 0.008, 0.0);
    v_blurTexCoords[ 9] = v_texCoord + vec2( 0.012, 0.0);
    v_blurTexCoords[10] = v_texCoord + vec2( 0.016, 0.0);
    v_blurTexCoords[11] = v_texCoord + vec2( 0.020, 0.0);
    v_blurTexCoords[12] = v_texCoord + vec2( 0.024, 0.0);
    v_blurTexCoords[13] = v_texCoord + vec2( 0.028, 0.0);
}

和

//Vertical
attribute vec4 a_position;
attribute vec2 a_texCoord;

varying vec2 v_texCoord;
varying vec2 v_blurTexCoords[14];

void main()
{
    gl_Position = a_position;
    v_texCoord = a_texCoord;
    v_blurTexCoords[ 0] = v_texCoord + vec2(0.0, -0.028);
    v_blurTexCoords[ 1] = v_texCoord + vec2(0.0, -0.024);
    v_blurTexCoords[ 2] = v_texCoord + vec2(0.0, -0.020);
    v_blurTexCoords[ 3] = v_texCoord + vec2(0.0, -0.016);
    v_blurTexCoords[ 4] = v_texCoord + vec2(0.0, -0.012);
    v_blurTexCoords[ 5] = v_texCoord + vec2(0.0, -0.008);
    v_blurTexCoords[ 6] = v_texCoord + vec2(0.0, -0.004);
    v_blurTexCoords[ 7] = v_texCoord + vec2(0.0,  0.004);
    v_blurTexCoords[ 8] = v_texCoord + vec2(0.0,  0.008);
    v_blurTexCoords[ 9] = v_texCoord + vec2(0.0,  0.012);
    v_blurTexCoords[10] = v_texCoord + vec2(0.0,  0.016);
    v_blurTexCoords[11] = v_texCoord + vec2(0.0,  0.020);
    v_blurTexCoords[12] = v_texCoord + vec2(0.0,  0.024);
    v_blurTexCoords[13] = v_texCoord + vec2(0.0,  0.028);
}

但是如何在Threejs素材中添加两遍顶点着色器？

我还在尝试学习如何使用着色器，所以请告诉我，我是否走错了方向......

Answer 1

着色器程序在webgl中始终只有1个顶点着色器和1个片段着色器。当2遍渲染是nessecary时，有2个程序都在场景中的同一数据集上执行。

最有可能在你的2遍渲染中，你得到2个渲染为2个渲染的程序，然后在一个帧中组合。一个例子是http://threejs.org/examples/#webgl_rtt。

如何将多个顶点着色器添加到ShaderMaterial？

1 个答案: