Unity lights of type “Area” emit light across a rectangle or a disc (1). In Predict Engine, an area light can emit from any geometry (2).

To define an area light that emits light from a custom geometry, you must : 

• Define the geometry,

• Convert it to an area light : right-click on the GameObject in the Hierarchy, menu "PredictiveSuite/Light/Physical Light/Convert Geometry To Area Light" : this will add a "Light" component of type "Area" and an UVR Light Settings component to the geometry,

• Define the area light by editing the Light Settings component.

You can also proceed the other way around : 

• Create a light with a Light Settings component,

• Add a geometry to it : right-click on the GameObject in the Hierarchy, menu "PredictSuite/Light/Physical Light/Add custom geometry to area light" : this will add a "Mesh Renderer" and a "Mesh Filter" component to the light,

• Set the right geometry on the mesh filter and define a valid material on the mesh renderer.

Geometries can be complex and have several submeshes. If you define an area light on a geometry that has several submeshes, an additional Submesh field will be available on the UVR Light Settings component to let you choose wich submesh should be emitting light.

Double sided geometries

When you define an area light with a lambertian or uniform intensity, you can choose if the light should be emitted from both sides of the geometry surface or not (see example bellow). Other intensity types do not require this setting as the emission direction is already defined in the intensity definition.

If the light has an UVR Light Settings component, the "Emit on both sides" toggle enables you to choose how the light is emitted. 

If the light does not have an UVR Light Settings component, the emission direction can be defined in the PredictiveSuite preferences : see section bellow.

When you only define a light using the Unity Light component, a default geometry is used in Predict Engine based on the Unity settings. By default, the area light in Predict Engine will emit light from a transparent geometry in the direction defined by the Unity light. You can edit these default settings in the PredictSuite preferences, section Matter Settings.

• The "Emit on both sides" option defines whether the light is emitted from both sides of the geometry or only in the direction defined by the Unity light,

• The "Default Material" is the material used on the geometry in Predict Engine.