Spot Light emits light from a single point in a cone shape in a specific direction. Spot Lights are useful for simulating light from objects such as lampposts and flashlights. By changing Inner Cone Angle and Outer Cone Angle you can modify the shape of the light.
|Radius||Light range (in world units).|
|Source Radius||Light build source radius (in world units).|
|Fall Off Exponent||Controls the radial falloff of light. Works only if option Use Inverse Squared Falloff is disabled.|
|Use Inverse Squared Falloff||If checked, physically based inverse squared distance falloff will be used.|
|Color||Light emission color.|
|Brightness||Light brightness parameter. Controls intensity of the light emitted by this actor.|
|Inner Cone Angle||Light inner cone angle (in degrees).|
|Outer Cone Angle||Light outer cone angle (in degrees).|
|View Distance||Controls light visibility range. The distance at which the light be completely faded. Use value 0 to always draw a light.|
|Minimum Roughness||Controls the minimum roughness value used to clamp material surface roughness during shading. Can help with softening specular highlights.|
By using Source Radius property you can change the spot light source build dimensions. This allows to simulate area lights and bring more realism into the scenes.
Light Fall Off
Flax offers two modes for lights fall off. Custom Exponent parameter can be used or Inverse Squared Falloff mode Inverse quared mode gives more use physically based distance falloff, where Radius is only clamping the light's contribution. Hovewer using manual light falloff exponent gives more customization.
|Mode||Describes how visual element casts shadows. Possible options:
|Sharpness||Controls shadows sharpness. Can be used to tweak the penumbra width.|
|Strength||Controls dynamic shadows blending strength. Default is 1 for fully opaque shadows, value 0 disables shadows.|
|Distance||Light shadows rendering distance (in world units).|
|Fade Distance||Light shadows fade off distance (in world units).|
|Depth Bias||Controls dynamic shadows depth bias value. Depth bias used for shadow map comparison.|
|Normal Offset Scale||Controls dynamic shadows normal vector offset scale. A factor specifying the offset to add to the calculated shadow map depth with respect to the surface normal.|
|Contact Shadows Length||The length of the rays for contact shadows computed via the screen-space tracing. Set this to values higher than 0 to enable screen-space shadows rendering for this light. This improves the shadowing details. Actual ray distance is based on the pixel distance from the camera.|
To learn more about shadows in Flax see this page.
Volumetric Fog Properties
|Scattering Intensity||Controls how much this light will contribute to the Volumetric Fog. When set to 0, there is no contribution.|
|Cast Shadow||If checked, light will cast a volumetric shadow to Volumetric Fog. Also shadows casting by this light should be enabled in order to make it cast volumetric fog shadow.|
To learn more about Volumetric Fog effect see this page.
IES Profile Properties
|IES Texture||Assigned IES texture (light profiles from real world measured data). Learn more about it here.|
|Use IES Brightness||If checked, light brightness will be based on imported IES Profile brightness. Then use Brightness Scale parameter to scale it.|
|Brightness Scale||Custom scale parameter for the light brightness if option Use IES Brightness is checked.|
To learn more about IES Light Profiles see this page.