Definition Tone Mapping / ACES (ACEScg)

Tone mapping translates "scene-referred" renders with a wide dynamic range into the "display-referred" range of a target display (sRGB/Rec.709/HDR) so that contrasts, colors and highlights appear natural. ACES (ACEScg) is an open colour space and pipeline system that standardizes this translation - from input (IDT) to render (ACEScg) to output (ODT). Here we show how we use ACES in realistic fire renderings: 3D Fireplace & Stove Rendering.

For uniform material reactions we also refer to PBR - Physically Based Rendering.

Why tone mapping & ACES are crucial for brand images

• Consistency across channels: Catalog still, social cut, product video, web viewer - with ACES, the visual language remains stable. So we keep the same look from still to video: 3D product video - modular furniture.
• Natural feeling of light: highlights do not clip hard, shadows "sink" less - rooms and products look photographic.
• Team scaling: Uniform color space avoids correction loops between DCC, grading and 3D render studio.

Basics: Scene- vs. display-referred, ACEScg & ODT

• Scene-referred: linear render values with a large dynamic range (e.g. ACEScg).
• Display-referred: what a specific display can show (sRGB/Rec.709, HDR formats).
• IDT/ODT/RRT: ACES defines Input Device Transform, Output Device Transform and a reference tone curve(RRT) for reproducible results. In-depth: compact overview at the Academy (ACES) → Academy Color Encoding System - Overview.

Comparison table: ACES vs. "Standard sRGB" vs. "Filmic"

ACES integration via OpenColorIO is recommended for color management in DCC/Grading → OpenColorIO - Using ACES Config.

Practical workflow (7 steps) - robust for interior & product

1. Set references: CI-Mood, target display (sRGB/Rec.709 or HDR).
2. Set renderer to scene-referred: internal calculation in ACEScg, create materials in PBR sense (albedo without light).
3. Select IDT: Correctly transfer source material (e.g. texture photography) into the scene.
4. Setting light: physically plausible sources + HDRI / Image-Based Lighting for natural ambient light. Interior lighting design in practice: Virtual bathroom design - Canyon House. We show how we use warm flame light with GI and glass reflections for branded products in the 3D fireplace & stove rendering.
5. Transform ODT/viewing: Define target display (e.g. Rec.709-ODT); do not double "gamma-n" intermediate steps.
6. QA & dailies: comparison with material samples; clean handover points for video playout 3D animation & product video.
7. Delivery & Variants: Stills for 3D product visualizationinteractive assets in 3D viewer (note sRGB display there again). Brand space with consistent ACES display: Interactive brand spaces - FOR Home Haus 2025.

Common errors & quick fixes

FAQ - Tone Mapping / ACES (ACEScg)

What is tone mapping and why do I need ACES?

Tone mapping translates renders with a high dynamic range into the area of a display so that contrasts appear natural. ACES provides a standardized pipeline to ensure that looks remain consistent across tools and playout channels.

What is the difference between ACES and ACEScg?

ACES is the overall system (color spaces, transforms). ACEScg is the linear working color space for rendering/compositing (scene-referred); the output is then sent to the target display via ODT (e.g. sRGB/Rec.709).

What do IDT, RRT and ODT mean?

IDT (Input Device Transform) brings sources correctly into the scene color space, RRT is the reference tone curve, ODT (Output Device Transform) maps the result to the target display. Together they ensure reproducible colors and contrasts.

Why do renders look different on the web than in the DCC?

Because browsers expect sRGB display. Export with suitable ODT/conversion to sRGB and deactivate additional viewer tone curves, otherwise you will unintentionally add a second curve.

How do I avoid the most common error "double tone curve"?

Keep only one viewing transform active (e.g. ACES ODT), do not use any further "Auto-Contrast/Gamma" in the export and deactivate additional look operators in the target tool (browser/player).

When is ACES worthwhile - and when is sRGB/Filmic sufficient?

ACES is worthwhile for series, moving images, multi-team pipelines and cross-channel CI imagery. An sRGB/Filmic setup can be sufficient for quick single stills or previews - as soon as several playouts are planned, ACES saves time and corrections.