Gradient Sky

The Gradient Sky Volume component override controls settings relevant to rendering a simple representation of the sky. It allows you to define three colors, the Top, Middle, and Bottom, which HDRP interpolates between to create a gradient sky.

You can alter these values at runtime. This component also exposes options that enable you to define how HDRP updates the indirect lighting the sky generates in the Scene.

Using Gradient Sky

Gradient Sky uses the Volume framework, so to enable and modify Gradient Sky properties, you must add a Gradient Sky override to a Volume in your Scene. To add Gradient Sky to a Volume:

1. In the Scene or Hierarchy view, select a GameObject that contains a Volume component to view it in the Inspector.
2. In the Inspector, navigate to Add Override > Sky and click on Gradient Sky.

After you add a Gradient Sky override, you must set the Volume to use Gradient Sky. The Visual Environment override controls which type of sky the Volume uses. In the Visual Environment override, navigate to the Sky section and set the Type to Gradient Sky. HDRP now renders a Gradient Sky for any Camera this Volume affects.

API

To access and control this override at runtime, use the Volume scripting API. Because of how the Volume system works, you edit properties in a different way to standard Unity components. There are also other nuances to be aware of too, such as each property has an overrideState. This indicates to the Volume system whether to use the property value you set, or use the default value stored in the Volume Profile. For information on how to use the API correctly, see Volume scripting API.

Properties

To edit properties in any Volume component override, enable the checkbox to the left of the property. This also tells HDRP to use the property value you specify for the Volume component rather than the default value. If you disable the checkbox, HDRP ignores the property you set and uses the Volume’s default value for that property instead.

Property	Description
Top	Use the color picker to select the color of the upper hemisphere of the sky.
Middle	Use the color picker to select the color of the horizon.
Bottom	Use the color picker to select the color of the lower hemisphere of the sky. This is below the horizon.
Gradient Diffusion	Set the size of the Middle property in the Skybox. Higher values make the gradient thinner, shrinking the size of the Middle section. Low values make the gradient thicker, increasing the size of the Middle section.
Intensity Mode	Use the drop-down to select the method that HDRP uses to calculate the sky intensity. • Exposure: HDRP calculates intensity from an exposure value in EV100. • Multiplier: HDRP calculates intensity from a flat multiplier.
- Exposure	Set the amount of light per unit area that HDRP applies to the HDRI Sky cubemap. This property only appears when you select Exposure from the Intensity Mode drop-down.
- Multiplier	Set the multiplier for HDRP to apply to the Scene as environmental light. HDRP multiplies the environment light in your Scene by this value. This property only appears when you select Multiplier from the Intensity Mode drop-down.
Update Mode	Use the drop-down to set the rate at which HDRP updates the sky environment (using Ambient and Reflection Probes). • On Changed: HDRP updates the sky environment when one of the sky properties changes. • On Demand: HDRP waits until you manually call for a sky environment update from a script. • Realtime: HDRP updates the sky environment at regular intervals defined by the Update Period.
- Update Period	Set the period (in seconds) for HDRP to update the sky environment. Set the value to 0 if you want HDRP to update the sky environment every frame. This property only appears when you set the Update Mode to Realtime.