In 3D Mapping lights are placed normal to the lighting sphere. This means that wherever the light is placed on the Canvas, once this image is mapped onto the HDRI sphere, then the light maintains the correct shape and appearance.
3D mapped lights can be promoted to Area Lights in your 3D scene. See Area Lights for more details.
Transform (Core) Settings for a light with 3D mapping
Latitude
The latitude defines the vertical position on the canvas. Values range from -90 (north pole) to 90 (south pole). A value of zero will position the light at the equator.
Longitude
This determines the horizontal position of the light on the canvas. Values range from 0 to 360 degrees around the virtual sphere.
Width
This is the horizontal dimension of the light. Increase this to make the light wider.
Height
This is the vertical dimension of the light. Increase this to make the light taller.
Rotation
This changes the orientation of the light around an axis at right angles to the canvas plane. It is calibrated in degrees from 0 to 360.
Transform (Extended) Settings for a light with 3D mapping
Handle U
Sets the horizontal position of the light's Handle.
Handle V
Sets the vertical position of the light's Handle.
See Light Handle for more information
Rotations: Enable Advanced Rotations
Activate to allow lights to be oriented in 3 axis with the additional advanced settings.
Rotation Mode and Adjustments
Select the Rotation Mode to determine the orientation behavior of the light. Make adjustments to the orientation using the controls.
See Advanced Rotations for a full explanation.