godot/doc/classes/SpotLight3D.xml
Hugo Locurcio 92fa8fd54a
Document caveats of high attenuation in OmniLight3D and SpotLight3D
High attenuation values will negatively impact performance for 2 reasons:

- The light won't be culled as often.
- The light will cover more pixels, which have to be shaded individually.

Therefore, lower attenuation values (with a lower range to compensate)
should be preferred whenever possible.
2022-08-02 22:59:06 +02:00

30 lines
2.4 KiB
XML

<?xml version="1.0" encoding="UTF-8" ?>
<class name="SpotLight3D" inherits="Light3D" version="4.0">
<brief_description>
A spotlight, such as a reflector spotlight or a lantern.
</brief_description>
<description>
A Spotlight is a type of [Light3D] node that emits lights in a specific direction, in the shape of a cone. The light is attenuated through the distance. This attenuation can be configured by changing the energy, radius and attenuation parameters of [Light3D].
</description>
<tutorials>
<link title="3D lights and shadows">$DOCS_URL/tutorials/3d/lights_and_shadows.html</link>
<link title="Third Person Shooter Demo">https://godotengine.org/asset-library/asset/678</link>
</tutorials>
<members>
<member name="shadow_bias" type="float" setter="set_param" getter="get_param" overrides="Light3D" default="0.03" />
<member name="spot_angle" type="float" setter="set_param" getter="get_param" default="45.0">
The spotlight's angle in degrees.
</member>
<member name="spot_angle_attenuation" type="float" setter="set_param" getter="get_param" default="1.0">
The spotlight's [i]angular[/i] attenuation curve. See also [member spot_attenuation].
</member>
<member name="spot_attenuation" type="float" setter="set_param" getter="get_param" default="1.0">
The spotlight's light energy (drop-off) attenuation curve. A number of presets are available in the [b]Inspector[/b] by right-clicking the curve. Zero and negative values are allowed but can produce unusual effects. See also [member spot_angle_attenuation].
[b]Note:[/b] Very high [member spot_attenuation] values (typically above 10) can impact performance negatively if the light is made to use a larger [member spot_range] to compensate. This is because culling opportunities will become less common and shading costs will be increased (as the light will cover more pixels on screen while resulting in the same amount of brightness). To improve performance, use the lowest [member spot_attenuation] value possible for the visuals you're trying to achieve.
</member>
<member name="spot_range" type="float" setter="set_param" getter="get_param" default="5.0">
The maximal range that can be reached by the spotlight. Note that the effectively lit area may appear to be smaller depending on the [member spot_attenuation] in use. No matter the [member spot_attenuation] in use, the light will never reach anything outside this range.
</member>
</members>
</class>