Sky

Paradise Sandbox comes with a physically-based sky system which also features true volumetric clouds and electric thunderstorms.

As well as the ocean, the sky is a component which can be added/removed to/from the scene. By default, all exterior (open-door) presets come with the sky already configured.

If you want to manually add or remove the sky in your scene, you can simply use the Plugins menu:

One time you have the sky component in your scene, select it by using the Project Explorer and change its properties by using the Property Editor:

As you possibly have already noticed, there are quite parameters for customizing the sky look, so we will study them group by group:

Time of the day

The time of the day defines the position of the Sun/Moon at a moment. The Sun/Moon position can be dynamic if the Time multiplier is different from zero.

In Paradise Sandbox, the time of the day is a value between 0h and 24h and it's defined by the parameter Current time. The Sunrise and Sunset parameters define the hour of the day when the sun is at the horizont.

  • Current time: Local time of the day. A value between 0h and 24h.
  • Time multiplier: Time multiplier which increments/decrements the current time dynamically. Useful when showcasing day/night cycles.
  • Sunrise: The time of the day when the Sun appears at the horizont.
  • Sunset: The time of the day when the Moon appears at the horizont.
  • East direction: Although this parameter doesn't affect the elevation of the Sun, it defines the direction of the sky where is appears. A value between 0º and 360º.
Moon

The look of the Moon is fully configurable: size, phase, halo intensity and halo strength.

In order to change the Moon parameters, perform a click on the Moon property and a drop-menu will be shown:

  • Size: Size of the Moon
  • Phase: Phase of the Moon. Image of different phases of the Moon:

  • Halo intensity: Intensity (color multiplier) of the halo effect.
  • Halo strength: Shape of the halo. Different from intensity.
Advanced: Atmosphere settings

This is the most complicated section but will allow you to create any kind of sky: from desertic redish sunsets to tropical blue skies.

  • Mie multiplier: In the practice it affects to how big the Sun is:

  • Rayleigh multiplier: Affects the turbulence (or, alternatively, clarity) of the atmosphere:

  • Inner and outer radius: Defines the distance between the ground of the planet and the end of the atmosphere. You can play with the values to achieve extraterrestial atmospheres.
  • Samples: Resolution of the physically-based calculation. Usually 4 samples are enough.
  • Phase function: As well as the mie multiplier, it controls the size of the Sun. Use this value for a more fine tunning.
  • HDR: Use high dynamic range colors. Should be always checked.
  • Exposure: Energy of the atmosphere light contribution:

  • Wavelength: Defines the color of the atmosphere. Play with the values (in little increments) to achieve different tones of color:

Layered (simple) clouds

Layered clouds are high-altitude cloud formations which are changes with the time of day (in opposition to the true volumetric clouds which can be animated independently of the time of the day).

On / off comparison:

Volumetric clouds

Paradise Sandbox also includes an advanced system for simulation and rendering of volumetric clouds and electric thunderstorms:

The volumetric cloud system allows the user to create unique clouds by varying:

  • Enable: Turn on / off volumetric clouds
  • Time dependency: Links or not the cloud field animation with the current time of the day. Usually your Time multiplier will be zero so you would want to disable time dependency in order to the cloud field moving through the sky.
  • Humidity: Value between 0 and 1 which defines the humidity of the atmosphere: how dense the cloud field is:

  • Clouds size: Average size of clouds
  • Scale: Scale of the cloud field
  • Noise scale: Scale of noise effects applied to volumetric clouds:

  • Wind speed and wind direction: Define the speed and direction of the wind/clouds
  • Distance falling: Affects to how the cloud field is rendered at the horizont:

  • Light response: Defines how the sun light affects the clouds. 4 parameters: Sun light power - power of the light, Beta multiplier - multiplier of the light power when the camera is looking at the sun direction, Ambient color multiplier - how much th ambient light tints the clouds (see Ambient factors to generate the ambient color applied to clouds and modulated by this parameters) and Distance att - distance that fully tints the clouds using the sun light.
  • Ambient factors: Defines how the ambient light tints clouds. 4 factors: constant, linear, cuadratic and cubic.
Thunderstorm

Finally, the volumetric cloud system supports electric thunderstorms (lightnings). Asociated parameters:

  • Enable: Switch on/off lightings generation
  • Time between lightnings: Average time between lightnings generation
  • Lightning color: Color of lightnings
  • Lightning time multiplier: Defines how fast the lightning effect is simulated

Linking the atmosphere with the scene ambient light and main light

The sky component is able to override the scene ambient and background colors and also to link the Sun to any light of the scene:

  • Background color: Use the atmosphere color as background color
  • Ambient color: Use the atmosphere color as ambient color
  • Overridden light: Link the Sun to any light (color and position/direction). Usually you will want to override the MainLight light.