Basic knowledge about HDR
You can open the Environment Editor by pressing the F6 key
Key components for HDR lighting
The following sections must be enabled in the environment preset settings:
eye_adaptation - enabled
tone_mapping - enabled
tone_mapping - aces
The main HDR parameter is target_exposure in the eye_adaptation section.
Conditions for correct HDR operation
For HDR to function properly, there must be light at varying brightness ranges, with screen brightness differing by at least 5-10 times.
The working range is from 0.001 to 10.
Lighting components
| Component | Description |
|---|---|
light.ambient_intensity | Intensity of ambient lighting that spreads evenly across the scene. |
light.diffuse_intensity | Intensity of diffuse lighting that determines the brightness of surfaces facing the light source. |
light.envmap_amount | Amount of light reflected from the environmental map, used for creating reflections. |
light.environment_intensity | Intensity of lighting from the environment, including natural and reflected light. |
haze.intensity | Intensity of haze or fog, adding an atmospheric effect and altering scene visibility. |
HDR sky textures | Use of high dynamic range textures for the sky to achieve realistic light transitions. |
Quadratic attenuation in light sources | A light attenuation formula that realistically distributes light as distance increases. |
Speculars for all materials | Adjustment of specular properties for all materials, adding highlights and reflected light |
The final color for lighting parameters containing intensity (e.g., light.ambient, light.diffuse, haze.color, and others) is calculated using the formula:
result_color = color * intensity
The final brightness depends on the brightness of the color itself and the intensity parameter
Real-life brightness levels
| Parameter | Light Intensity | Description |
|---|---|---|
candle | 10 | Imitation of candle light, creating a cozy atmosphere |
cloud_at_night | 0.00033 | Dim lighting under a cloudy night sky |
cloud_at_night (lit by moon) | 0.0419 | Cloudy night sky illuminated by the moon |
frosted_bulb_60w | 1200 | Light from a 60-watt frosted bulb |
monitor | 3 | Imitation of light from a monitor |
moon_surface | 30 | Light mimicking the luminosity of the moon's surface |
sky_cloudy | 20 | Light on a cloudy day |
sky_day | 60 | Bright sunlight during the day |
sky_night (lit by moon) | 0.00085 | Night light when illuminated by the moon |
sky_night_dark | 4e-006 | Very dim night lighting |
sky_night_noon | 0.00124 | Night lighting without additional light sources |
sky_rise_skyline | 0.0019 | Dawn or dusk |
star | 0.00196 | Light from a distant star |
Tonemapper settings
Tonemapper settings should be the same across the entire project
If you need a specific frame appearance - use a LUT.
For understanding the operation of adaptation and HDR, it is very useful to enable the display of curves for HDR parameters using the console command v_hdrHistogramOn 1
Decoding Figure 1:
Red line - tonemapping curve (automatically calculated by the tonemapping formula and its parameters)
Yellow line - brightness value selected by auto exposure
Green lines - exposure_min, exposure_max
Blue lines - horizontal brightness readings
Objects for testing color
To test colors in game resources, there are 3 test entity located in the service folder of the Entity Editor [1]:
color_checker_gradient - for testing the display of monochrome gradients
color_checker_kodak - for testing brightness levels
color_checker - for testing the transmission of standard shades
Learn more about creating and configuring environment presets
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