EffectComposer second pass “overwrites” first pass

问题

i want to render a texture on the background and the 3dscene in the foreground. i used the effectcomposer to do this.

how ever my first pass (the background) seems to be "overwritten" with the 2nd pass (the scene) the result only the scene gets drawn with a black background. it looks like the background of the second pass isnt drawn transparent or the transparancy is lost.

http://jsfiddle.net/mdwzx1f8/8/

var renderTex = new THREE.TexturePass(myTex);
var renderScene = new THREE.RenderPass(scene, camera);

composer.addPass(renderTex);
composer.addPass(renderScene);

var effectCopy = new THREE.ShaderPass(THREE.CopyShader);
effectCopy.renderToScreen = true;
composer.addPass(effectCopy);

i hope someone can take a quick look at it and point me in the right direction

thanks in advance

Updates:

07/07/2015

I tried clearing the zbuffer with renderer.clear(false, true, false);
Found a post on masking which i looked at but it wasnt added to
threejs as far as i can tell
https://github.com/mrdoob/three.js/issues/2448

08/07/2015

Found another interesting page https://github.com/mrdoob/three.js/issues/5979 not sure if this is related yet
Updated the fiddle if you comment line 53 you will see the 1st pass which should be visible if the scene background is drawn transparent

回答1:

Bobafett in the threejs irc channel helped me out and he found my issue, it turns out that i called: renderer.autoClear = false; instead onrenderer.autoClearColor = false;

Here is the modified and working fiddle: http://jsfiddle.net/mdwzx1f8/9/

I would like to thank all who have helped me in the search for the solution

来源：https://stackoverflow.com/questions/31181748/effectcomposer-second-pass-overwrites-first-pass

标签

three.js