Lights

There are four types of point lights:

  1. Point light: Emits light equally in all directions
  2. Spot light: Casts a cone of light from a specific location, in one direction
  3. IES light: An IES light is a digital profile of a real world light. It is useful for simulating physically accurate lights. You can find free IES files online
  4. Projector light: Projects an image

Point light types

Point light Spot light IES light Project light

You can also apply an emitter material to a face to create an indirect source of illumination. The front side of the face will glow.

CREATING LIGHTS

To create a light:

  • Open the Thea tool window
  • Select the ‘Light’ tab
  • Click on one of the buttons at the bottom of the tab to create a point, spot, IES, or projector light
  • Left-click to place the light source, and left-click again to place its target

While creating a Thea light, the distance from the origin point to the target, defines the initial power of the light that is needed to reach the target.
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”

Once created, the light's name and properties are displayed in the light tab.

If a light looks faint in the rendering, check the exposure settings (ISO, Shutter speed, and f-number). For interior scenes, respective values of 800, 30, and 2.4 are usually sufficient

EMITTANCE PROPERTIES

Emittance properties are described in detail here: Editing Lights

GENERAL PROPERTIES

  • Enabled: Turns the light On/Off
  • Shadow (Presto): Turns shadowcasting On/Off
  • Soft shadow - radius (m): Makes the light cast soft shadows by changing the radius (in meters)
  • Container: If the light is placed inside a container made of a material with the properties of a medium, or if it is submerged in water, ‘Container’ lets you select a material for the container. It can be also used to show a volumetric projection of light
  • Evaluation: Instructs the light whether it should affect the listed material properties. Example: If the diffuse is unchecked, then the light will not affect the diffuse color of the object

Light options