- Qt 5.15
- Qt 3D
- QML Types
- SpotLight QML Type
- Qt 5.15.18 Reference Documentation

# SpotLight QML Type

Encapsulate a Spot Light object in a Qt 3D scene. More...

Import Statement: | import Qt3D.Render 2.15
Since: | Qt 5.5
Instantiates: | QSpotLight

- List of all members, including inherited members

## Properties

- constantAttenuation : float
- cutOffAngle : float
- linearAttenuation : float
- localDirection : vector3d
- quadraticAttenuation : float

## Detailed Description

A spotlight is a light source that emits a cone of light in a particular direction.

A spotlight uses three attenuation factors to describe how the intensity of the light decreases over distance. These factors are designed to be used together in calcuating total attenuation. For the materials in Qt3D Extras the following formula is used, where distance is the distance from the light to the surface being rendered:

     totalAttenuation = 1.0 / (constantAttenuation + (linearAttenuation * distance) + (quadraticAttenuation * distance * distance));

Custom materials may choose to interpret these factors differently.

## Property Documentation

constantAttenuation : float

Specifies the constant attenuation of the spot light.

Note: The exact meaning and use of this property is up to the material implementation.

cutOffAngle : float

Specifies the cut off angle of the spot light.

Note: The exact meaning and use of this property is up to the material implementation.

linearAttenuation : float

Specifies the linear attenuation of the spot light.

Note: The exact meaning and use of this property is up to the material implementation.

localDirection : vector3d

Specifies the local direction of the spot light.

Note: The exact meaning and use of this property is up to the material implementation.

quadraticAttenuation : float

Specifies the quadratic attenuation of the spot light.

Note: The exact meaning and use of this property is up to the material implementation.