仅在MacBook Pro（Retina）上在Three.js中使用SSAO的伪像

Question

I'm currently using the SSAO shader provided in the Three.js examples . It works perfectly on most of my machines aside from my MacBook Pro Retina. The MBP rendered SSAO perfectly until a few weeks ago (potentially after a firmware upgrade on the MBP).

As it stands, the MBP renders SSAO scenes with a huge amount of flickering artefacts all over the screen, like so:

Scene code here

Scene found here

This same code renders perfectly on other machines. I have seen this problem on other MBPs so I'm confident that it's not a single issue.

Aside from the firmware update, I've not changed anything on this MBP between it working and the artefacts appearing (the code is the same).

If I remove the SSAO effect then the scene renders perfectly.

Any ideas?

Answer 1

I think you need to take into account the devicePixelRatio. Take a look at this example http://uihacker.blogspot.gr/2013/03/javascript-antialias-post-processing.html

Answer 2

The fact that this is happening on all browsers on the Retina Macbook, but appears works on other devices (looks fine on the Chromebook Pixel) suggests that this may be a driver bug on OSX. There may be a way to work around it in WebGL, but I would recommend filing a bug report with Apple at the very least.

Answer 3

I had the exact same problem on a non-retina MacBook Pro, so it seems to be a bug in the NVidia graphics driver. One thing that seems to influence the behavior is the material blending. I get better results with the depthmaterial blending set to THREE.NoBlending:

// depth
var depthShader = THREE.ShaderLib[ "depthRGBA" ];
var depthUniforms = THREE.UniformsUtils.clone( depthShader.uniforms );

depthMaterial = new THREE.ShaderMaterial( { fragmentShader: depthShader.fragmentShader, vertexShader: depthShader.vertexShader, uniforms: depthUniforms } );
depthMaterial.blending = THREE.NoBlending; //add this

Also the near plane setting of the camera seemingly had effect on the rendering.

Answer 4

我通过将相机对象的“ near”属性更改为大于1的值来解决此问题。仍不确定为什么可以解决此问题，但SSAO现在可以在Retina MacBook上完美运行。