DenrimRendererKit

DenrimRendererKit is a MoonRay-inspired Swift Package for high-quality Metal path tracing on Apple platforms. It is built for Denrim products, but the repository is kept useful as a standalone renderer: you can load scripted scenes, render material previews, benchmark backends, and use the Swift API directly from an app or tool.

The renderer and material system are shaped by MoonRay-style production rendering ideas: physically based layered materials, predictable scriptable scenes, useful diagnostics, and a path toward a polished Apple-native offline/preview renderer. DenrimRendererKit is not a MoonRay port or shader-compatible implementation; it uses MoonRay as a quality and material-design reference.

Features

• Progressive Metal path tracer with flat BVH fallback and Metal ray tracing traversal on supported devices.
• denrim CLI for rendering .denrim SceneScript files and built-in material previews.
• SceneScript with script-relative assets, includes, mesh instances, render defaults, and readable grouped arguments.
• OBJ and PLY mesh loading with preserved normals and UVs.
• ImageIO texture loading with explicit sRGB/linear handling, checker/solid/generated textures, and tangent-space normal maps.
• Direct emissive-triangle lighting, HDRI environment sampling, and benchmark timing reports.
• Rough dielectric, metal, clearcoat, thin-film, sheen/fuzz, transmission, absorption, volume scattering, and random-walk subsurface controls.
• Built-in material preset catalog with generated preview thumbnails.
• Beauty, depth, normal, albedo, material ID, object ID, and motion-vector outputs.
• Unit, parser, backend parity, AOV, and render smoke tests.

DiningRoom Preview

The DiningRoom scene lives at Examples/SceneScripts/Quality/DiningRoom/dining-room.denrim. It carries render defaults in the script itself:

render output ../../../Renders/DiningRoom.png size hd spp 512 quality final backend automatic

Run it with:

swift run -c release denrim -- Examples/SceneScripts/Quality/DiningRoom/dining-room.denrim

For a quick smoke render, override the script defaults:

swift run denrim -- Examples/SceneScripts/Quality/DiningRoom/dining-room.denrim \
    --output /tmp/denrim-dining-room.png \
    --width 320 \
    --height 180 \
    --samples 1 \
    --quality interactive

Materials

Built-in materials are exposed through BuiltInMaterialLibrary and SceneScript's material name preset preset-id form. The thumbnails below are generated with Examples/Tools/render-built-in-materials.sh.

Preview	Preset	Category	Description
	matte.clay	Diffuse	Warm neutral diffuse clay for model previews.
	matte.paper	Diffuse	Soft off-white paper with low specular response.
	matte.charcoal	Diffuse	Dark rough diffuse surface.
	plastic.soft-black	Plastic	Dark plastic with readable broad highlights.
	plastic.gloss-white	Plastic	White molded plastic with a clear glossy coat.
	rubber.black	Plastic	Very rough black rubber.
	fabric.velvet-purple	Fabric	Velvet-like fabric using the sheen/fuzz lobe.
	fabric.denim-blue	Fabric	Rough blue fabric with a gentle grazing sheen.
	subsurface.skin-warm	Subsurface	Warm organic random-walk subsurface scattering.
	subsurface.wax-cream	Subsurface	Soft creamy wax with broad internal scattering.
	liquid.milk	Liquid	Cloudy refractive liquid with absorption and volume scattering.
	subsurface.jade-green	Subsurface	Dense green stone with colored multiple scattering.
	metal.chrome	Metal	Polished neutral mirror-like metal.
	metal.aluminum	Metal	Clean bright aluminum.
	metal.brushed-aluminum	Metal	Anisotropic satin aluminum.
	metal.gold	Metal	Polished warm gold.
	metal.copper	Metal	Polished copper.
	coating.car-red	Coating	Glossy red paint with a clearcoat layer.
	coating.pearl-white	Coating	Bright coated paint with subtle warm clearcoat tint.
	coating.iridescent-amber	Coating	Glossy amber coated surface with thin-film color shift.
	glass.clear	Glass	Clear solid dielectric glass.
	glass.frosted	Glass	Rough transmissive glass.
	glass.thin-pane	Glass	Zero-thickness glass pane for windows and tabletops.
	liquid.water	Liquid	Clear water with IOR 1.333.
	ceramic.white	Ceramic	Glazed white ceramic.
	ceramic.porcelain	Ceramic	Smooth porcelain with soft off-white tint.
	emission.warm-panel	Emission	Warm white area-light material.
	emission.cool-panel	Emission	Cool white area-light material.

Render a material preview directly:

swift run denrim -- material matte.clay --samples 64 --quality interactive
swift run denrim -- material liquid.milk --samples 1024 --quality final

Refresh the material gallery:

./Examples/Tools/render-built-in-materials.sh

Swift API

import DenrimRendererKit

let renderer = try DenrimRenderer()
let scene = RenderScene.cornellBox()
let session = try renderer.makeSession(
    scene: scene,
    settings: RenderSettings(width: 512, height: 512, maxBounces: 4)
)

try session.render(samples: 64, to: outputURL)

Use built-in material presets from Swift:

let material = BuiltInMaterialLibrary.material(named: "metal.brushed-aluminum")
let previews = BuiltInMaterialLibrary.previews

Load a scripted scene:

let sceneURL = URL(fileURLWithPath: "Examples/SceneScripts/Quality/DiningRoom/dining-room.denrim")
let scene = try SceneScript.parse(contentsOf: sceneURL)
let defaults = scene.renderDefaults

SceneScript And CLI

denrim renders .denrim SceneScript files, resolves relative assets beside the script, writes PNG output, prints progress during normal renders, and prints benchmark timings at the end. Scripts can carry render defaults; explicit CLI flags override them.

swift run denrim -- Examples/SceneScripts/Quality/DiningRoom/dining-room.denrim
swift run denrim help render
swift run denrim help material

Useful render options:

swift run denrim -- Examples/SceneScripts/MaterialVariants/glossy-metal-reference.denrim \
    --output /tmp/glossy.png \
    --samples 64 \
    --quality interactive \
    --backend automatic

Use --output-type depth|normal|albedo|material-id|object-id|motion-vector to export AOVs, --denoise apple-svgf or --denoise simple for denoiser comparisons, --backend flat-bvh|metal-ray-tracing for backend measurements, and --report-output report.json or --json for benchmark JSON. --json suppresses progress output so stdout stays parseable.

Testing

swift test

Performance benchmarks are intentionally separate from normal tests:

DENRIM_RUN_PERFORMANCE_TESTS=1 swift test --filter PerformanceBenchmarkTests

Documentation

• Materials
• SceneScript
• Performance
• Testing

License

DenrimRendererKit is released under the Apache License 2.0.