Depth-Aware Blur

Smooth noisy screen-space results without bleeding across foreground/background boundaries. depthAwareBlurShaderPassPipeline combines Gaussian spatial weights with scene-depth similarity in two separable bilateral-filter passes.

GitHub

At a Glance

Property	Value
Exports	depthAwareBlur and depthAwareBlurShaderPassPipeline
Backend	WebGPU
Render passes	Two separable bilateral-filter passes
Required binding	depthTexture
Intermediate storage	One renderer-owned scratch texture

Usage

import {ShaderPassRenderer} from '@luma.gl/engine';
import {depthAwareBlurShaderPassPipeline} from '@luma.gl/effects';

const renderer = new ShaderPassRenderer(device, {
  shaderPasses: [depthAwareBlurShaderPassPipeline]
});

renderer.renderToScreen({
  sourceTexture: noisyLightingTexture,
  bindings: {depthTexture: sceneDepthTexture},
  uniforms: {depthAwareBlur: {radius: 4, depthSigma: 0.01, spatialSigma: 3}}
});

Parameters

Parameter	Default	Range	Description
radius	4	1 to 8	Number of bilateral-filter samples on each side of the center pixel.
depthSigma	0.01	Minimum 0.0001	Accepted depth variation; smaller values preserve stronger depth discontinuities.
spatialSigma	3	Minimum 0.1	Width of the Gaussian spatial weighting profile.
direction	[1, 0]	Set by the pipeline	Horizontal or vertical sample direction for the low-level standalone pass.

The pipeline automatically supplies [1, 0] and [0, 1] for its two blur directions. Near-depth neighbors contribute normally, while samples separated by a depth edge are exponentially reduced.

Performance and Composition

Each direction visits at most eight samples on either side of the center pixel. The reusable filter also appears inside several higher-level scene-aware pipelines, where it denoises occlusion, indirect illumination, reflections, or volumetric lighting while retaining silhouettes.

Related Effects

• Gaussian Blur deliberately ignores depth boundaries.
• SSAO uses edge-aware filtering to stabilize ambient-occlusion estimates.
• Screen-Space Global Illumination denoises indirect light with depth- and normal-aware filtering.