Rendering / Metal 4 · Direct3D 12

From GPU tables to the display

Bindless resources, GPU-driven meshlets, and a shared lighting architecture, on native Metal 4 and Direct3D 12 backends.

The geometry path

Main asset: Amazon Lumberyard Bistro by Amazon Lumberyard · via NVIDIA ORCA · CC BY 4.0

01 / Geometry

Culling and submission on the GPU

Scene geometry, materials, and textures live in shared GPU tables. Compute passes find visible meshlets and build indirect draw streams, keeping scene submission on the GPU.

01Address geometry and materials through shared tables
02Reject clusters outside the view, facing away, or occluded
03Build visible streams and indirect draw arguments
04Shade the surviving geometry through shared material data

Hikari meshlet debug view showing the Sponza courtyard geometry as individually colored clusters. — Sponza / Meshlet visualization
Main asset: Sponza Atrium by Frank Meinl / Crytek · License: source unverified

Bindless resources: Geometry, materials, and textures live in GPU tables. Shared resource indices replace per-material texture rebinding.
GPU-driven submission: Compute builds the visible geometry streams and indirect draw arguments. The GPU drives scene-mesh submission.
Meshlet culling: Meshlets bring frustum, backface-cone, and two-phase Hi-Z culling to the GPU. Shadows use the same geometry-pulling architecture.
Ray tracing: Ray-traced shadows, ambient occlusion, reflections, and global illumination share the renderer’s material and geometry data.
Screen-space effects: SSAO, SSGI, and hierarchical screen-space reflections add contact, bounce light, and surface detail, with configurable quality budgets.
Froxel volumetrics: Froxel volumetrics integrate light through fog and bounded media. Shape shafts, local smoke, and atmosphere with volume materials.

Stylized worlds

Stylized scenes, same renderer

Saturated colour, warm light, and soft haze. A stylized Japanese street, rendered by the same pipeline as the Bistro captures.

A stylized Japanese street rendered in Hikari, with orange and blue buildings, a wooden bridge, vivid green shopfront details, and warm haze against a bright sky. — Stylized scene rendered in Hikari · EXR capture converted to SDR WebP.
Main asset: Stylized Little Japanese Town Street by Michał Solarek · CC Attribution

02 / Light & atmosphere

Light that fills the air

Froxels divide the camera’s view into a 3D grid. The renderer injects lighting and integrates scattering through global fog and bounded local volumes. Volume materials shape the medium; scene shadow maps give the haze structure.

Sunlight streams through tall warehouse windows into volumetric haze, illuminating drifting dust above a debris-covered floor. — Volumetric lighting study · In-engine EXR capture, converted to SDR WebP.
Main asset: Abandoned Warehouse - Interior Scene by Aurélien Martel · CC Attribution

03 / HDR

HDR output that follows the display

Scene colour stays linear and unbounded through exposure, bloom, and grading. Display mapping then resolves the image against the screen’s peak brightness and paper white. Hikari selects the output encoding for the active surface.

Scene-linear lightDisplay mapping + BT.2390 roll-offEDR · scRGB · HDR10

Automatic SDR fallback when HDR is unavailable. Web captures are SDR previews.

A dark spaceship corridor with metallic wall panels, glowing red lights and bright highlights diffused through haze. — Spaceship corridor · HDR lighting rendered in Hikari. Tone-mapped SDR preview of the EXR capture.
Main asset: Spaceship Corridor by the_table · CC Attribution

Peak-aware tone mapping: Display-aware tone mapping and BT.2390 roll-off fit highlights to the screen’s current peak brightness.
Paper-white reference: UI and diffuse white share a configurable brightness reference, independent of HDR highlights.
Automatic HDR and SDR: Detects OS-enabled HDR, falls back to SDR, and switches live without restarting the engine.