Variables

Variable

Definition

Value

Brightness Power

Adjusts light levels to compensate for variations via power function (e.g 0.5 = square root dependence, 1.0 = no adjustment).

0.01 to 1.0

Altitude

Higher Altitude, less atmosphere. Will allow more light to pass through.

1 to 8

Max Altitude

Max altitude that will be used for fade and sky colour calculations, in km.

2.0 and 100.0

Elevations

Number of elevations / height of table.

Powers of 2 between 4 and 256.

Distances

Number of distances / width of table.

Powers of 2 between 4 and 128.

Distance Range

Maximum distance for fade.

5.0 and 2000.0.

Variable

Definition

Value

Light source

Which directional light source trueSKY should control

Directional Light

Drive Light Direction

If trueSKY should alter the angle of the Directional Light based on the movement of the Sun and Moon.

Bool

Light Units

Radiometric or Photometric Light Units. Only use Photometric if you Unreal’s Exposure settings.

Radiometric or Photometric

Brightness

A Brightness Multiplier applied to the Sun, Moon and Sky.

0.1 to 10.0

Gamma

Gamma adjustment value.

0.0 to 10.0

Direct Light

Amount of direct light on the clouds.

0.0 to 4.0

Indirect Light

Amount of indirect light on the clouds.

0.0 to 4.0

Ambient Light

Amount of ambient light on the clouds.

0.0 to 4.0

Extinction

Amount of light scattered per metre (larger values = darker clouds).

0.0001 to 100.0

Mie Asymmetry

Anisotropic distribution of direct lighting, or eccentricity.

0.0 to 1.0

trueSKY Light

This applies a constant ambient light over the whole scene. Check out Unreal’s SkyLight for information on most of the variables. This will just cover any variables we have added.

Variable

Definition

Value

Update Frequency

How often the trueSKYLight will update, in frames. 1 means every frame, two mean every other frame etc.

1 to 100

Blend

How much to blend new updates with previous values.

0 to 1

Amortization

How much to Amortize rendering.

1 to 8

All Faces

Whether to fill all cube maps faces on every update.

Bool

All Mips

Whether to fill all mipmaps on every update.

Bool

Diffuse Multiplier

Multiplier for the diffuse illumination from the skylight.

0.0 to 20.0

Specular Multiplier

Multiplier for the specular reflections from the skylight.

0.0 to 20.0

Gamma Correction

Gamma adjustment to apply.

0.0 to 20.0