我是three.js的新手，但我无法实现以下效果：渲染2个场景并将其与混合着色器混合。第一个TexturePass可以，但是第二个则像频闪仪一样闪烁。结果可以在这里看到：https://codepen.io/anon/pen/jYKqyj?editors=0010#0
这是代码：
THREE.Custom = THREE.Custom || {};
// Taken from https://github.com/stemkoski/stemkoski.github.com/blob/master/Three.js/js/shaders/AdditiveBlendShader.js
THREE.Custom.AdditiveShader = {
uniforms: {
tDiffuse: { type: "t", value: null },
tAdd: { type: "t", value: null },
fCoeff: { type: "f", value: 1.0 }
},
vertexShader: [
"varying vec2 vUv;",
"void main() {",
"vUv = uv;",
"gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );",
"}"
].join("\n"),
fragmentShader: [
"uniform sampler2D tDiffuse;",
"uniform sampler2D tAdd;",
"uniform float fCoeff;",
"varying vec2 vUv;",
"void main() {",
"vec4 texel = texture2D( tDiffuse, vUv );",
"vec4 add = texture2D( tAdd, vUv );",
"gl_FragColor = texel + add * fCoeff, 1.0;",
"}"
].join("\n")
};
var TestBlending = (function (){
var canvasWidth, canvasHeight, canvasRatio;
var clock = new THREE.Clock();
var container, camera, scene1, scene2, renderer;
var stats, statsDisplay = true;
var box1, box2;
var composerFinal, composerScene1, composerScene2, composerBlending, renderTarget;
var composerDebugScene1, composerDebugScene2;
var delta;
function createScene1 () {
scene1 = new THREE.Scene();
scene1.name = "scene1";
var light = new THREE.DirectionalLight( 0xffffff, 1 );
light.position.set( 0, 10, 20 );
light.name = "light1";
scene1.add(light);
var material = new THREE.MeshPhongMaterial( { color: 0xcc00cc } );
var geometry = new THREE.BoxGeometry( 1, 1, 1 );
box1 = new THREE.Mesh( geometry, material );
scene1.add( box1 );
}
function createScene2 () {
scene2 = new THREE.Scene();
scene2.name = "scene2";
var light = new THREE.DirectionalLight( 0xffffff, 1 );
light.position.set( 0, 10, 20 );
light.name = "light2";
scene2.add(light);
var material = new THREE.MeshPhongMaterial( { color: 0x33cc33 } );
var geometry = new THREE.BoxGeometry( 1, 1, 1 );
box2 = new THREE.Mesh( geometry, material );
scene2.add( box2 );
}
function init() {
container = document.getElementById('test_blending');
updateCanvasSize();
// RENDERER
renderer = new THREE.WebGLRenderer( {
antialias: true,
alpha: true
} );
renderer.setPixelRatio( (window.devicePixelRatio) ? window.devicePixelRatio : 1 );
renderer.setSize(canvasWidth, canvasHeight);
renderer.setClearColor( new THREE.Color(0x0), 0 );
renderer.autoClear = false;
// CAMERA
camera = new THREE.PerspectiveCamera( 10, canvasRatio, 1, 10000 );
camera.position.set(0, 0, 30);
camera.lookAt(new THREE.Vector3(0,0,0));
createScene1();
createScene2();
window.addEventListener( 'resize', onWindowResize, false );
}
function updateCanvasSize () {
canvasWidth = window.innerWidth;
canvasHeight = window.innerHeight;
canvasRatio = canvasWidth / canvasHeight;
}
function initProcessingPasses () {
var parameters = {
minFilter: THREE.LinearFilter,
magFilter: THREE.LinearFilter,
format: THREE.RGBAFormat,
stencilBuffer: true
};
renderTarget = new THREE.WebGLRenderTarget( canvasWidth, canvasHeight, parameters );
processing = { pass: {}, texture: {} };
processing.pass.clear = new THREE.ClearPass();
processing.pass.renderScene1 = new THREE.RenderPass( scene1, camera );
processing.pass.renderScene1.clear = true;
processing.pass.renderScene1.renderToScreen = false;
processing.pass.renderScene1.clearDepth = true;
processing.pass.renderScene2 = new THREE.RenderPass( scene2, camera );
processing.pass.renderScene2.clear = true;
processing.pass.renderScene2.renderToScreen = false;
processing.pass.renderScene2.clearDepth = true;
processing.pass.blending = new THREE.ShaderPass( THREE.Custom.AdditiveShader );
//processing.pass.blending.needsSwap = true;
processing.pass.blending.clear = true;
processing.pass.blending.renderToScreen = false;
processing.pass.output = new THREE.ShaderPass( THREE.CopyShader );
processing.pass.output.renderToScreen = true;
setPostProcessingPasses();
}
function setPostProcessingPasses () {
console.log('setPostProcessingPasses');
composerScene1 = null;
composerScene1 = new THREE.EffectComposer( renderer, renderTarget );
composerScene1.addPass( processing.pass.clear );
composerScene1.addPass( processing.pass.renderScene1 );
processing.texture.renderedScene1 = new THREE.TexturePass(composerScene1.renderTarget2.texture);
composerScene2 = null;
composerScene2 = new THREE.EffectComposer( renderer, renderTarget );
composerScene2.addPass( processing.pass.clear );
composerScene2.addPass( processing.pass.renderScene2 );
processing.texture.renderedScene2 = new THREE.TexturePass(composerScene2.renderTarget2.texture);
composerBlending = null;
composerBlending = new THREE.EffectComposer( renderer, renderTarget );
composerBlending.addPass( processing.pass.clear );
composerBlending.addPass( processing.texture.renderedScene1 );
processing.pass.blending.uniforms[ 'tAdd' ].value = composerScene2.renderTarget2.texture;
composerBlending.addPass( processing.pass.blending );
processing.texture.renderedBlending = new THREE.TexturePass(composerBlending.renderTarget2.texture);
composerFinal = null;
composerFinal = new THREE.EffectComposer( renderer, renderTarget );
composerFinal.addPass( processing.pass.clear );
composerFinal.addPass( processing.texture.renderedBlending );
composerFinal.addPass( processing.pass.output );
composerDebugScene1 = new THREE.EffectComposer( renderer, renderTarget );
composerDebugScene1.addPass( processing.pass.clear );
composerDebugScene1.addPass( processing.texture.renderedScene1 );
composerDebugScene1.addPass( processing.pass.output );
composerDebugScene2 = new THREE.EffectComposer( renderer, renderTarget );
composerDebugScene2.addPass( processing.pass.clear );
composerDebugScene2.addPass( processing.texture.renderedScene2 );
composerDebugScene2.addPass( processing.pass.output );
}
function addStats (container) {
stats = new Stats();
if (statsDisplay) container.appendChild( stats.dom );
}
function addToDOM() {
var canvas = container.getElementsByTagName('canvas');
if (canvas.length>0) {
container.removeChild(canvas[0]);
}
container.appendChild( renderer.domElement );
addStats(container);
}
function animate() {
window.requestAnimationFrame(animate);
var time = performance.now() * 0.001;
var cDelta = clock.getDelta();
box1.rotation.y = time / 5;
box1.rotation.x = 10;
box2.rotation.z = time / -5;
box2.rotation.x = time / -5;
box2.rotation.y = 5;
stats.update();
render();
}
function render() {
delta = clock.getDelta();;
renderer.setViewport( 0, 0, canvasWidth, canvasHeight );
composerScene1.render(delta);
composerScene2.render(delta);
composerBlending.render(delta);
composerFinal.render(delta);
// DEBUG
renderer.setViewport( 0, 0, canvasWidth/3, canvasHeight/3 );
composerDebugScene1.render(delta);
renderer.setViewport( canvasWidth/3*2, canvasHeight/3*2, canvasWidth/3, canvasHeight/3 );
composerDebugScene2.render(delta);
}
function onWindowResize() {
camera.aspect = canvasRatio;
camera.updateProjectionMatrix();
renderer.setSize( canvasWidth, canvasHeight );
composerScene1.setSize( canvasWidth, canvasHeight );
composerScene2.setSize( canvasWidth, canvasHeight );
composerBlending.setSize( canvasWidth, canvasHeight );
composerFinal.setSize( canvasWidth, canvasHeight );
}
return {
init: function () {
init();
initProcessingPasses();
addToDOM();
animate();
}
}
})();
TestBlending.init();
任何帮助将不胜感激。谢谢
主要问题是，processing.pass.renderScene1的目标纹理被添加了两次。它作为单独的通道添加到composerBlending中，并在processing.pass.blending中使用。