Editing Lights

Double‐click a light component (or single‐click when the Thea Tool is open) to access the light's properties.

Point Light and Spotlight Properties

Point lights and spotlights share several properties:
Emittance: The color of the light is controlled by the color of the light's material. But if Temperature is enabled, it controls the color of the light.

All lights have the following parameters:

  • Power: Defines the power of the emitter and the available power units (Lumens, Watts, W/sr, W/nm, W/nm/sr)
  • Efficacy: The energy loss of the power that is converted to visible light.
    Maximum efficacy is 683 lm/W which corresponds to lights with no energy loss.
    Common light have efficacy between 2 and 50lm/W.
  • Attenuation: Defines the light's attenuation. Available options are none, Inverse and Inverse Square.
  • Temperature (K): Set the color of the light in Kelvin.

Create a new SketchUp material, set a custom color and apply the material to the Thea Light.


Unique Spotlight Properties

Spotlights have two additional values that control their cone shape.
Hot Spot: The angle at the tip of the cone, where light is emitted at full intensity.
Fall Off: The angle at which the light fades away.

IES Light Properties

Multiplier: Use this option to modify the intensity of the IES light.

In general, it is recommended to keep the default value of 1.0 because IES lights simulate physically accurate lights. To make the rendering brighter, adjust the display settings instead. The default IES light uses the sample .ies file. A preview image is displayed below. You can select another IES file using the drop‐down menu and clicking the ‘Load’ button. To use your own IES file, select ‘Other file’ from the drop‐down menu and click ‘Load’. Select the desired IES file, which will be saved with the light component.

The IES description is saved inside each IES light component. You can safely share SketchUp models with others without including .ies files.


Projector Light Properties

A projector light emits light in the shape of a square pyramid to display images on surfaces. If an image is not selected, the projector light will emit a color (defined by the color of the light's material or the Temperature parameter). Use 'W x H' (Width and Height) to change the size of the projected image. By default, the aspect ratio is locked. Click on the chain icon to unlock it. Power, Efficacy, and Attenuation are the same as they are for other light types.

It is important that the distance between the light source and any adjacent geometry is greater than the radius of the light; otherwise, the final rendering may contain undesired “noise.”