SsaoPass: artifacts with depth buffer

Description of the problem

The SSAO example shows several artifacts when i change the camera settings. In particular, the camera near clipping plane value is critical therefore. For a project of mine i need a small camera near value, but when setting up a useful value z-fighting artifacts occure. Both on the beauty and the ssao output mode.

When switching off the depthTexture of beautyRenderTarget in SSAOPass.js, the beauty output mode delivers a useful rendering again, but then the depth information is missing of course.

	this.beautyRenderTarget = new THREE.WebGLRenderTarget( this.width, this.height, {
		minFilter: THREE.LinearFilter,
		magFilter: THREE.LinearFilter,
		format: THREE.RGBAFormat,
		// depthTexture: depthTexture,
		// depthBuffer: true
	} );

Another attempt was to use the logarithmic depth buffer on THREE.WebGLRenderer, but the reimplementation 2f9bd63 seems not to contain a normalization regarding the logarithmic nature of the depth buffer.

I’d like to know how to achieve a good effect with the logarithmic depth buffer. What is the data type and the value range of the depth texture and why is only the x (or red) channel of interest. Next i’d like to know why the rendering quality seems to increase when i switch off the depthTexture (as seen in code above) for the beauty pass?

Three.js version

• r110
• r103

Browser

• All of them
• Chrome
• Firefox

OS

• Windows
• macOS
• Linux (on my linux installation on the same intel hd-gpu powered laptop there are no issues)

Hardware Requirements (graphics card, VR Device, …)

Depth / Stencil Bits: [24, 8] extensions WEBGL_depth_texture and EXT_frag_depth are available

[vanruesc]

Sure, that sounds reasonable. My intention is just to provide another opinion on the matter.

[vanruesc]

Does this have no side effects?

I haven’t encountered any issues with this depth texture setup. As far as I can tell, WebGLTextures already contains code for handling DepthStencilFormat and it also seems to handle stencil buffers correctly.

Stencil + Depth Texture support was added in #9368 which came after #8596 but didn’t close or reference the latter, although @Bryce-Summers reported that this PR fixed his CSG problem. Depth/Stencil management was also further enhanced by #9774.

I’ll check again if there are any problems with using stencil + depth texture and will report back later.

UNSIGNED_INT_24_8_WEBGL enables only a 24-bit depth texture whereas float enables 32-bit. so it’s not equivalent.

That’s true. I can only speak for myself, but to me 24-bit depth appears to be sufficient.