Untold Engine 0.18.1: AgX Tonemapping, Procedural Sky, and a Simpler Color Pipeline

[untoldengine]

Untold Engine 0.18.1 is now available. This is a color-pipeline and rendering-fidelity release: a native AgX tonemap operator, standalone .cube color-grade LUTs, a first pass at a procedural sky, Blender-consistent directional-light units, and fixes for normal-map noise and off-axis texture aliasing.

AgX Tonemapping & a Simpler Color Pipeline

Blender 4.0+ defaults to the AgX View Transform, and the engine now has a native Metal port of it — setPostFX(.tonemapOperator(.agx)) — alongside the existing ACES Filmic default. It's a runtime shader operator, not a baked asset, so it costs nothing at export time and works on any scene regardless of how it was exported.

This release also removes --bake-color-management and --bake-material from the exporter. Baking a scene's exact Blender display transform into a whole-scene LUT was the only way to get pixel-perfect parity with a non-stock View Transform, Look, or OCIO config, but it added a Blender-render step to every export and a second, harder-to-reason-about code path in the renderer. The native AgX/ACES operators plus externally-authored .cube grades (below) now cover the common cases with far less machinery. Assets exported before the flag's removal still load correctly — loadSceneAuthored recognizes and clears the legacy baked LUT for backward compatibility.

Docs: Using Materials, Textures, and Color Management

External .cube Color-Grade LUTs, Without a Scene Export

--color-grade-lut stages a standard .cube 3D LUT — hand-authored, or exported from DaVinci Resolve, Nuke, or any other grading tool — alongside a scene export, layered as a creative grade on top of whichever tonemap operator ran. The engine parses .cube text directly and uploads it to a native Metal 3D texture, so no proprietary container or .utex conversion step is involved.

LUT-engine2.mov

This release adds a standalone runtime entry point for the same mechanism, independent of any scene export:

setColorGradeLUT(filename: "warm_grade", withExtension: "cube")

The active tonemap operator and grade LUT are also now serialized with the scene, so a saved/reloaded scene keeps its authored look, and the LUT itself is bundled automatically into shipped app builds.

Docs: Using the Registration System

A First Pass at Procedural Sky

The renderer can now draw a procedural atmospheric sky as the non-XR background, as an alternative to the debug/editor grid, via setRenderingEnvironment(.sky(true)). Sun position for this background is driven by a new elevation/azimuth pair on directional lights — getSunElevationAzimuth / setSunElevationAzimuth — a pure re-parameterization of the light's existing orientation, so it can't drift out of sync with the transform.

sky-rendering2.mov

This is early — it's shipping disabled by default while it gets more visual polish — but it's there to opt into and build against.

Blender-Consistent Directional Light Units

Directional lights now support .strength(_:), a radiometric unit (irradiance, W/m²) matching Blender Sun's "Strength" property, alongside the existing .power(_:) convenience for point/spot/area lights. Newly-created directional lights default to values tuned for the new sky background rather than the arbitrary intensity used previously.

Texture Fidelity Fixes

• Normal map noise: 16-bit source precision was being discarded before ASTC compression even ran, and the compressor's default error metric was tuned for color data, not unit vectors — together producing visible noise on fine surface detail (fabric weave, wrinkles) once lit. Normal maps now keep 16-bit precision through export and are compressed with astcenc's -normal -perceptual mode, repacked as 2-component X+Y with Z reconstructed in the shader.
• Anisotropic filtering is now enabled (16x) on every texture sampler in the engine's shared sampler cache, fixing stair-stepped aliasing on textures viewed at a grazing angle — floors, tiled walls, anything seen off-axis.

Docs: Using Materials, Textures, and Color Management

Other Fixes

• untoldengine bootstrap now installs lz4 into Blender's own bundled Python interpreter rather than the system python3 — the two interpreters don't share sys.path, so --optimize exports were failing with ModuleNotFoundError even after a successful bootstrap.
• The editor's grid pass now blends with the sky pass instead of one fully replacing the other, so the floor grid reads correctly against the new background.

Closing

0.18.1 trades a heavier, Blender-render-dependent color pipeline for a simpler, faster one — native AgX/ACES plus composable .cube grades — while starting the groundwork for a proper sky and improving texture fidelity across the board. As always, thanks for testing and filing issues, and feedback on the new sky background and color pipeline is especially welcome while both are still early.