HDRI Sky
The HDRI Sky Volume component override controls settings you can use to set up an HDRI Sky. An HDRI Sky is a simple sky representation that uses a cubemap texture. This component also enables you to define how HDRP updates the indirect lighting the sky generates in the Scene.
Tip: Unity HDRI Pack is available on the Unity Asset Store and provides 7 pre-converted HDR Cubemaps ready for use within your Project.
Using HDRI Sky
HDRI Sky uses the Volume framework, so to enable and modify HDRI Sky properties, you must add an HDRI Sky override to a Volume in your Scene. To add HDRI Sky to a Volume:
- In the Scene or Hierarchy view, select a GameObject that contains a Volume component to view it in the Inspector.
- In the Inspector, navigate to Add Override > Sky and click on HDRI Sky.
After you add an HDRI Sky override, you must set the Volume to use HDRI 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 HDRI Sky. HDRP now renders an HDRI Sky for any Camera this Volume affects.
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 |
|---|---|
| HDRI Sky | Assign a HDRI Texture that HDRP uses to render the sky. |
| Enable Distortion | Enable or disable UV distortion. |
| - Distortion Mode | Use the drop-down to select the method that HDRP uses to calculate the sky distortion. • Procedural: HDRP distorts the sky using a uniform wind direction. • Flowmap: HDRP distorts the sky with a user provided flowmap. |
| -- Flowmap | Assign a flowmap, in LatLong layout, that HDRP uses to distort UVs when rendering the sky. This property only appears when you select Flowmap from the Distortion Mode drop-down. |
| -- Upper Hemisphere Only | Check the box if the flowmap contains distortion for the sky above the horizon only. This property only appears when you select Flowmap from the Distortion Mode drop-down. |
| - Scroll direction | Use the slider to set the scrolling direction for the distortion. |
| - Scroll speed | Modify the speed at which HDRP scrolls the distortion texture. |
| 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. • Lux: HDRP calculates intensity in terms of a target Lux value. |
| - 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. |
| - Desired Lux Value | Set an absolute intensity for the HDR Texture you set in HDRI Sky, in Lux. This value represents the light received in a direction perpendicular to the ground. This is similar to the Lux unit you use to represent the Sun and thus is complimentary. This property only appears when you select Lux from the Sky Intensity Mode drop-down. |
| - Upper Hemisphere Lux Value | Displays the relative intensity, in Lux, for the current HDR texture set in HDRI Sky. The final multiplier HDRP applies for intensity is Desired Lux Value / Upper Hemisphere Lux Value. This field is an informative helper. This property only appears when you select Lux from the Sky Intensity Mode drop-down. |
| Rotation | Use the slider to set the angle to rotate the cubemap, in degrees. |
| 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. |
Avanced Properties
Note: for being able to have Ambient Occlusion on the Backplate we have to enable "Direct Lighting Strenght" on the Ambient Occlusion component. As the Backplate didn't have Global Illumination he can only have Ambient Occlusion from direct lighting.
| Property | Description |
|---|---|
| Backplate Type |  Set the shape of the Backplate. |
| Ground Level | Ground Level in the same scale. |
| - Scale | HDRP uses the X and Y values of this property scale the backplate (for Ellipse X and Y must be different). |
| - Projection Distance | HDRP uses this number to control the projection of the bottom hemisphere of the HDRI on the backplate. Small projection distance implies higher pixels density with more distortion, large projection distance implies less pixels density with less distortion. |
| - Backplate Rotation | Rotation of the physical backplate. |
| - Texture Rotation | Rotation of the texture projected in the backplate. |
| Texture Offset | Offset of the texture projected in the backplate. |
| Blend Amount | Percentage of the transition with the backplate and background HDRI. 0% means no blending, 25% means the blending start at the end of the boundary of the backplate, 50% means the blending start from the middle of the backplate and 100% means the transition start from the center of the backplate with a smoothstep |
| - Point Light Shadow | Allow the backplate to receive the shadow from the Point/Spot Lights. |
| - Directional Light Shadow | Allow the backplate to receive the shadow from the The Directional Light. |
| - Area Light Shadow | Allow the backplate to receive the shadow from the Area Lights. |
| - Reset Color | Reset the saved Default Shadow Tint for the shadow, the Default Shadow Tint is computed when the HDRI Changes, the Shadow Tint can be ajusted in intensity. |