virtualx-engine/doc/classes/PhysicalSkyMaterial.xml
clayjohn 385ee5c70b Implement Physical Light Units as an optional setting.
This allows light sources to be specified in physical light units in addition to the regular energy multiplier. In order to avoid loss of precision at high values, brightness values are premultiplied by an exposure normalization value.

In support of Physical Light Units this PR also renames CameraEffects to CameraAttributes.
2022-08-31 12:14:46 -07:00

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XML

<?xml version="1.0" encoding="UTF-8" ?>
<class name="PhysicalSkyMaterial" inherits="Material" version="4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
<brief_description>
[Sky] [Material] used for a physically based sky.
</brief_description>
<description>
The [PhysicalSkyMaterial] uses the Preetham analytic daylight model to draw a sky based on physical properties. This results in a substantially more realistic sky than the [ProceduralSkyMaterial], but it is slightly slower and less flexible.
The [PhysicalSkyMaterial] only supports one sun. The color, energy, and direction of the sun are taken from the first [DirectionalLight3D] in the scene tree.
As it is based on a daylight model, the sky fades to black as the sunset ends. If you want a full day/night cycle, you will have to add a night sky by converting this to a [ShaderMaterial] and adding a night sky directly into the resulting shader.
</description>
<tutorials>
</tutorials>
<members>
<member name="energy_multiplier" type="float" setter="set_energy_multiplier" getter="get_energy_multiplier" default="1.0">
</member>
<member name="ground_color" type="Color" setter="set_ground_color" getter="get_ground_color" default="Color(0.1, 0.07, 0.034, 1)">
Modulates the [Color] on the bottom half of the sky to represent the ground.
</member>
<member name="mie_coefficient" type="float" setter="set_mie_coefficient" getter="get_mie_coefficient" default="0.005">
Controls the strength of mie scattering for the sky. Mie scattering results from light colliding with larger particles (like water). On earth, mie scattering results in a whitish color around the sun and horizon.
</member>
<member name="mie_color" type="Color" setter="set_mie_color" getter="get_mie_color" default="Color(0.69, 0.729, 0.812, 1)">
Controls the [Color] of the mie scattering effect. While not physically accurate, this allows for the creation of alien-looking planets.
</member>
<member name="mie_eccentricity" type="float" setter="set_mie_eccentricity" getter="get_mie_eccentricity" default="0.8">
Controls the direction of the mie scattering. A value of [code]1[/code] means that when light hits a particle it's passing through straight forward. A value of [code]-1[/code] means that all light is scatter backwards.
</member>
<member name="night_sky" type="Texture2D" setter="set_night_sky" getter="get_night_sky">
[Texture2D] for the night sky. This is added to the sky, so if it is bright enough, it may be visible during the day.
</member>
<member name="rayleigh_coefficient" type="float" setter="set_rayleigh_coefficient" getter="get_rayleigh_coefficient" default="2.0">
Controls the strength of the Rayleigh scattering. Rayleigh scattering results from light colliding with small particles. It is responsible for the blue color of the sky.
</member>
<member name="rayleigh_color" type="Color" setter="set_rayleigh_color" getter="get_rayleigh_color" default="Color(0.3, 0.405, 0.6, 1)">
Controls the [Color] of the Rayleigh scattering. While not physically accurate, this allows for the creation of alien-looking planets. For example, setting this to a red [Color] results in a Mars-looking atmosphere with a corresponding blue sunset.
</member>
<member name="sun_disk_scale" type="float" setter="set_sun_disk_scale" getter="get_sun_disk_scale" default="1.0">
Sets the size of the sun disk. Default value is based on Sol's perceived size from Earth.
</member>
<member name="turbidity" type="float" setter="set_turbidity" getter="get_turbidity" default="10.0">
Sets the thickness of the atmosphere. High turbidity creates a foggy-looking atmosphere, while a low turbidity results in a clearer atmosphere.
</member>
<member name="use_debanding" type="bool" setter="set_use_debanding" getter="get_use_debanding" default="true">
If [code]true[/code], enables debanding. Debanding adds a small amount of noise which helps reduce banding that appears from the smooth changes in color in the sky.
</member>
</members>
</class>