Lights in the High Definition Render Pipeline
Use the Light component to create light sources in your Scene. The Light component controls the shape, color, and intensity of the light. It also controls whether or not the Light casts shadows in your Scene, as well as more advanced settings.
Creating Lights
There are two ways to add Lights to your Scene. You can create a new Light GameObject, or you can add a Light component to an existing GameObject.
To create a new Light Gameobject:
- In the Unity Editor, go to GameObject > Light
- Select the Light type you want to add.
Unity creates a new GameObject and attaches a Light component, as well as another High Definition Render Pipeline (HDRP) component: HD Additional Light Data. Unity places the new Light GameObject into your Scene, centered on your current view in the Scene window.
To add a Light component to an existing GameObject:
- Select the GameObject you want to add a Light.
- In the Inspector, click Add Component.
- Go to the Rendering section, and click Light. This creates a new Light source and attaches it to the currently selected GameObject. It also adds the HD Additional Light Data HDRP component.
Alternatively, you can search for "Light" in the Add Component window, then click Light to add the Light component.
Configuring Lights
To configure the properties of a Light, select a GameObject in your Scene with a Light component attached. See the Light’s properties in the Inspector window.
HDRP includes multiple types of Light. Although HDRP Lights share many properties, each one has its own unique behavior and set of properties.
For more detailed information on how to configure realistic light fixtures, see the Create High-Quality Light Fixtures in Unity expert guide. For general guidance on light intensities, see Physical light units.
Properties
The properties available for Lights are in separate sections. Each section contains some properties that all Lights share, and also properties that customize the behavior of the specific type of Light. These sections also contain more options that you can expose if you want to fine-tune your light's behavior. The sections are:
Animation
To make the Light work with the Animation window, when you click on the Add Property button, you need to use the properties inside the HD Additional Light Data component and not inside the Light component itself. If you do edit the properties inside the Light component, this modifies the built-in light values, which HDRP does not support. Alternatively, you can use the record button and modify the values directly inside the Inspector.
General
General properties control the type of Light, how HDRP processes this Light, and whether this Light affects everything in the Scene or just GameObjects on a specific Light Layer.
| Property | Description |
|---|---|
| Type | Defines the Light’s type. Lights of different Types behave differently, so when you change the Type, the properties change in the Inspector. Possible types are: • Directional • Point • Spot • Area |
| Mode | Specify the Light Mode that HDRP uses to determine how to bake a Light, if at all. Possible modes are: • Realtime: Unity performs the lighting calculations for Realtime Lights at runtime, once per frame. • Mixed: Mixed Lights combine elements of both realtime and baked lighting. • Baked: Unity performs lighting calculations for Baked Lights in the Unity Editor, and saves the results to disk as lighting data. Note that soft falloff/range attenuation is not supported for Baked Area Lights. |
| Light Layer | A mask that allows you to choose which Light Layers this Light affects. The affected Light only lights up Mesh Renderers or Terrain with a matching Rendering Layer Mask. This property only appears when you enable more options for this section. |
Light Types guide
| Type | Description |
|---|---|
| Spot | Emits light from a specified location and range over which the light diminishes. A Spot Light constrains the light it emits to an angle, which results in a cone-shaped region of illumination. The center of the cone points in the forward direction (z-axis) of the Light GameObject. Light also diminishes at the edges of the Spot Light’s cone. Increase the Spot Angle to increase the width of the cone. |
| Directional | Creates effects that are similar to sunlight in your Scene. Like sunlight, Directional Lights are distant light sources that HDRP treats as though they are infinitely far away. A Directional Light does not have any identifiable source position, and you can place the Light GameObject anywhere in the Scene. A Directional Light illuminates all GameObjects in the Scene as if the Light rays are parallel and always from the same direction. The Light disregards the distance between the Light itself and the target GameObject, so the Light does not diminish with distance |
| Point | Projects light out equally in all directions from a point in space. The direction of light hitting a surface is the line from the point of contact back to the center of the Light GameObject. The light intensity diminishes with increased distance from the Light, and it reaches zero at the distance specified in the Range field. Light intensity is inversely proportional to the square of the distance from the source. This is known as the Inverse-square law, and is similar to how light behaves in the real world. |
| Area | Projects light from a surface. Light shines in all directions uniformly from the surface of the rectangle. |
Limitations
Area Lights do not currently support Fabric or Hair Materials. This means they do not illuminate or cast shadows for Materials that use any of the following:
Shape
These settings define the area this Light affects. Each Light Type has its own unique Shape properties.
Spot Light
| Property | Description |
|---|---|
| Shape | HDRP Spot Lights can use three shapes. • Cone : Projects light from a single point at the GameObject’s position, out to a circular base, like a cone. Alter the radius of the circular base by changing the Outer Angle and the Range. • Pyramid : Projects light from a single point at the GameObject’s position onto a base that is a square with its side length equal to the diameter of the Cone. • Box : Projects light evenly across a rectangular area defined by a horizontal and vertical size. This light has no attenuation unless Range Attenuation is checked. |
| Outer Angle | The angle in degrees at the base of a Spot Light’s cone. This property is only for Lights with a Cone Shape. |
| Inner Angle (%) | Determines where the attenuation between the inner cone and the outer cone starts. Higher values cause the light at the edges of the Spot Light to fade out. Lower values stop the light from fading at the edges. This property is only for Lights with a Cone Shape. |
| Spot Angle | The angle in degrees used to determine the size of a Spot Light using a Pyramid shape. |
| Aspect Ratio | Adjusts the shape of a Pyramid Spot Light to create rectangular Spot Lights. Set this to 1 for a square projection. Values lower than 1 make the Light wider, from the point of origin. Values higher than 1 make the Light longer. This property is only for Lights with a Pyramid Shape. |
| Radius | The radius of the light source. This has an impact on the size of specular highlights, diffuse lighting falloff, and the softness of baked, ray-traced, and PCSS shadows. |
| Size X | For Box. Adjusts the horizontal size of the Box Light. No light shines outside of the dimensions you set. |
| Size Y | For Box. Adjusts the vertical size of the Box Light. No light shines outside of the dimensions you set. |
Directional Light
| Property | Description |
|---|---|
| Angular Diameter | Allows you to set the area of a distant light source through an angle in degrees. This has an impact on the size of specular highlights, and the softness of baked, ray-traced, and PCSS shadows. |
Point Light
| Property | Description |
|---|---|
| Radius | Defines the radius of the light source. This has an impact on the size of specular highlights, diffuse lighting falloff and the smoothness of baked shadows and ray-traced shadows. |
Area Light
| Property | Description |
|---|---|
| Shape | HDRP Area Lights can use three shapes. • Rectangle : Projects light from a rectangle shape at the GameObject’s position and orientation, in perpendicular direction, out to a certain Range. • Tube : Projects light from a single line at the GameObject’s position in every direction, out to a certain Range. This shape is only for Realtime Mode at the moment. • Disc : Projects light from a disc shape at the GameObject’s position and orientation, in perpendicular direction, out to a certain Range. This shape is only for Baked Mode at the moment. |
| Size X | For Rectangle. Defines the horizontal size of the Rectangle Light. |
| Size Y | For Rectangle. Defines the vertical size of the Rectangle Light. |
| Length | For Tube. Defines the length of the Tube Light. The center of the Light is the Transform Position and the Light itself extends out from the center symmetrically. The Length is the distance from one end of the tube to the other. |
| Radius | For Disc. Define the radius of the Disc Light. |
Celestial Body (Directional only)
These settings define the behavior of the light when you use it as a celestial body with the Physically Based Sky.
| Property | Description |
|---|---|
| Affect Physically Based Sky | When using a Physically Based Sky, this displays a sun disc in the sky in this Light's direction. The diameter, color, and intensity of the sun disc match the properties of this Directional Light. This property only appears when you enable more options for this section. |
| - Flare Size | Controls the size of the flare around the celestial body (in degrees).. |
| - Flare Falloff | Controls the falloff rate of flare intensity as the angle from the light increases. |
| - Flare Tint | Controls the tint of the flare of the celestial body. |
| - Surface Texture | Sets a 2D (disk) Texture for the surface of the celestial body. This acts like a multiplier. |
| - Surface Tint | Tints the surface of the celestial body. |
| - Distance | Controls the distance of the sun disc. This is useful if you have multiple sun discs in the sky and want to change their sort order. HDRP draws sun discs with smaller Distance values on top of those with larger Distance values. This property only appears when you enable more options for this section. |
Emission
These settings define the emissive behavior of your Light. You can set the Light’s color, strength, and maximum range. If you do not see these properties in the Light Inspector, make sure you expose more options. Most Lights share Emission properties. Below are the list of properties that more than one Light Type share, followed by unique properties only available for a single Light Type.
Shared Properties
| Property | Description |
|---|---|
| Color Temperature | Enable the checkbox to set the color temperature mode for this Light. Color Temperature mode adjusts the color of your Light based on a red-to-blue kelvin temperature scale. When enabled, this hides the Color property and exposes Filter and Temperature. Disable this checkbox to only display the Color field in the Inspector and use that as the Light color, without the temperature. |
| - Filter | Allows you to select the color of the Light’s filter using the colour picker. HDRP uses this and the Temperature property to calculate the final color of the Light. |
| - Temperature | Allows you to select a temperature that HDRP uses to calculate a color on a red-to-blue kelvin temperature scale. You can move the slider along the scale itself, or specify an exact temperature value in the field below the slider scale. This property includes an icon to the right of the slider which represents the light source that best matches the current value set. The icon is also a button which you can click to access a list of preset values that match real world light sources. |
| Color | Allows you to select the color of the Light using the colour picker. |
| Intensity | The strength of the Light. Intensity is expressed in the following units: • A Spot Light can use Lumen, Candela, Lux, and EV100. • A Directional Light can only use Lux. • A Point Light can use Lumen, Candela, Lux, and EV100. • A Area Light can use Lumen, Nits, and EV100. Generally, the further the light travels from its source, the weaker it gets. The only exception to this is the Directional Light which has the same intensity regardless of distance. For the rest of the Light types, lower values cause light to diminish closer to the source. Higher values cause light to diminish further away from the source. This property includes an icon to the right of the slider which represents the light source that best matches the current value set. The icon is also a button which you can click to access a list of preset values that match real world light sources. |
| Range | The range of influence for this Light. Defines how far the emitted light reaches. This property is available for all Light Types except Directional. |
| Indirect Multiplier | The intensity of indirect light in your Scene. A value of 1 mimics realistic light behavior. A value of 0 disables indirect lighting for this Light. If both Realtime and Baked Global Illumination are disabled in Lighting Settings (menu: Window > Rendering > Lighting Settings), the Indirect Multiplier has no effect. |
| Cookie | An RGB Texture that the Light projects. For example, to create silhouettes or patterned illumination for the Light. Texture shapes should be 2D for Spot and Directional Lights and Cube for Point Lights. Always import Cookie textures as the default texture type. This property is available for Spot, Area (Rectangular only), Directional, and Point Lights. Pyramid and Box lights will use an implicit 4x4 white cookie if none is specified. |
| IES Profile | An IES File that describe the light profile. If a cookie and an IES profile are setup, a linear average of them is used. (In case of an IES profile and a cookie used at the same time during light baking, only the cookie will be used). |
| IES cutoff angle (%) | Cut off of the IES Profile, as a percentage of the Outer angle. During a baking of a light map this parameter is not used. |
| Affect Diffuse | Enable the checkbox to apply diffuse lighting to this Light. This property only appears when you enable more options for this section. It is only available in Realtime or Mixed light Mode. |
| Affect Specular | Enable the checkbox to apply specular lighting to this Light. This property only appears when you enable more options for this section. It is only available in Realtime or Mixed light Mode. |
| Range Attenuation | Enable the checkbox to make this Light shine uniformly across its range. This stops light from fading around the edges. This setting is useful when the range limit is not visible on screen, and you do not want the edges of your light to fade out. This property is available for all Light Types except Directional. This property only appears when you enable more options for this section. It is only available in Realtime or Mixed light Mode for Type Area. |
| Fade Distance | The distance between the Light source and the Camera at which the Light begins to fade out. Measured in meters. This property is available for all Light Types except Directional. This property only appears when you enable more options for this section. It is only available in Realtime or Mixed light Mode. |
| Intensity Multiplier | A multiplier that gets applied to the intensity of the Light. Does not affect the intensity value, but only gets applied during the evaluation of the lighting. You can also modify this property via Timeline, Scripting or animation. The parameter lets you fade the Light in and out without having to store its original intensity. This property only appears when you enable more options for this section. It is only available in Realtime or Mixed light Mode. |
| Display Emissive Mesh | Enable the checkbox to make Unity automatically generate a Mesh with an emissive Material using the size, colour, and intensity of this Light. Unity automatically adds the Mesh and Material to the GameObject the Light component is attached to. This property is available for Rectangle and Tube Lights. This property only appears when you enable more options for this section. (In case of an IES profile and a cookie used at the same time, only the cookie will be displayed). |
| **Include For Ray Tracing ** | Enable the checkbox to make this Light active when the camera has the Ray Tracing Frame Setting enabled. This applies to both rasterization and ray tracing passes. This property only appears when you enable more options for this section. It is only available in Realtime or Mixed light Mode. |
Spot Light
| Property | Description |
|---|---|
| Reflector | Enable the checkbox to simulate a reflective surface behind the Spot Light. Spot Lights are Point Lights that are partly occluded at the back by a reflective surface. Simulating this reflective surface increases the intensity of the Spot Light because the reflective surface reflects light originally directed backwards to focus the intensity in the Spot Light’s direction. |
Directional Light
| Property | Description |
|---|---|
| Size X | The horizontal size of the projected cookie texture in pixels. This property only appears when you set a Cookie in the Light Inspector. |
| Size Y | The vertical size of the projected cookie texture in pixels. This property only appears when you set a Cookie in the Light Inspector. |
Volumetrics
These settings define the volumetric behavior of this Light. Alter these settings to change how this Light behaves with Atmospheric Scattering. All Light Types share the same Volumetric properties, except Area Light. It is only available in Realtime or Mixed light Mode.
Shared Properties
| Property | Description |
|---|---|
| Enable | Enable the checkbox to simulate light scattering through volumetric fog. Enabling this property allows you to edit the Dimmer and Shadow Dimmer properties. |
| Dimmer | Dims the volumetric lighting effect of this Light. |
| Shadow Dimmer | Dims the volumetric fog effect of this Light. Set this property to 0 to make the volumetric scattering compute faster. |
Shadows
Use this section to adjust the Shadows cast by this Light.
Unity exposes extra properties in this section depending on the Mode you set in the General section. Unity also exposes extra properties depending on the Filtering Quality set in your Unity Project’s HDRP Asset.
• For more information on shadow filtering in HDRP, see Shadow Filtering.
• For a list of the available filter quality presets in HDRP, see the Filtering Qualities table.
Properties
Shadow Map
This section is only available in Realtime or Mixed light Mode.
| Property | Description |
|---|---|
| Enable | Enable the checkbox to let this Light cast shadows. |
| Update Mode | Use the drop-down to select the mode that HDRP uses to determine when to update a shadow map. For information on the modes available, see the Shadows in HDRP documentation. |
| Resolution | Set the resolution of this Light’s shadow maps. Use the drop-down to select which quality mode to derive the resolution from. If you do not enable Use Quality Settings, or you select Custom, set the resolution, measured in pixels, in the input field. A higher resolution increases the fidelity of shadows at the cost of GPU performance and memory usage, so if you experience any performance issues, try using a lower value. |
| Near Plane | The distance, in meters, from the Light that GameObjects begin to cast shadows. |
| Shadowmask Mode | Defines how the shadowmask behaves for this Light. For detailed information on each Shadowmask Mode, see the documentation on Shadowmasks. This property is only visible if you tet the Mode, under General, to Mixed. |
| Slope-Scale Depth Bias | Use the slider to set the bias that HDRP adds to the distance in this Light's shadow map to avoid self intersection. This bias is proportional to the slope of the polygons represented in the shadow map. This property only appears when you enable more options for this section. |
| Normal Bias | Controls the amount of normal bias this Light applies along the normal of the illuminated surface. This property only appears when you enable more options for this section. |
| Custom Spot Angle | Enable the checkbox to use a custom angle to render shadow maps with. This property only appears if you select Spot from the Type drop-down and enable more options for this section. |
| Shadow Angle | Use the slider to set a custom angle to use for shadow map rendering. This property only appears if you enable Custom Spot Angle and enable more options for this section. |
| Shadow Cone | Use the slider to set the aperture of the shadow cone this area Light uses for shadowing. This property only appears if you select Rectangle from the Type drop-down. |
| EVSM Exponent | Use the slider to set the exponent this area Light uses for depth warping. EVSM modifies its shadow distribution representation by this exponent. Increase this value to reduce light leaking and change the appearance of the shadow. This property only appears if you select Rectangle from the Type drop-down and enable more options for this section. |
| Light Leak Bias | Use this slider to set the bias that HDRP uses to prevent light leaking through Scene geometry. Increasing this value prevents light leaks, but removes some of the shadow softness. This property only appears if you select Rectangle from the Type drop-down and enable more options for this section. |
| Variance Bias | Use the slider to fix numerical accuracy issues in the EVSM. This property only appears if you select Rectangle from the Type drop-down and enable more options for this section. |
| Blur Passes | Use the slider to set the number of blur passes HDRP performs on this shadow map. Increasing this value softens shadows, but impacts performance. This property only appears if you select Rectangle from the Type drop-down and enable more options for this section. |
| Dimmer | Dims the shadows this Light casts so they become more faded and transparent. This property only appears when you enable more options for this section. |
| Tint | Specifies whether HDRP should tint the shadows this Light casts. This option affects dynamic shadows, Contact Shadows, and ShadowMask. It does not affect baked shadows. You can use this behavior to change the color and transparency of shadows. This property only appears when you enable the more options for this section. |
| Penumbra Tint | Specifies whether the tint should only affect the shadow's penumbra. If you enable this property, HDRP only applies the color tint to the shadow's penumbra. If you disable this property, HDRP applies the color tint to the entire shadow including the penumbra. To change the color HDRP tints the shadow to, see the above Tint property. This property only appears when you enable the more options for this section. |
| Fade Distance | The distance, in meters, between the Camera and the Light at which shadows fade out. This property is available for Spot and Point Lights. This property only appears when you enable more options for this section. |
| Link Light Layer | Enable the checkbox to use the same Light Layer for shadows and lighting. If you enable this feature, then HDRP uses the Light Layer from the Light Layer drop-down in the General section for shadowing. If you disable this feature, then HDRP uses the Light Layer drop-down in this section for shadowing. This property only appears if you enable more options for this section.To access this property, enable Light Layers in your HDRP Asset. |
| Light Layer | Use the drop-down to set the Light Layer HDRP uses for shadowing. This Light therefore only casts shadows for GameObjects that use a matching Light Layer. For more information about using Light Layers for shadowing, see Shadow Light Layers. This property only appears if you enable more options for this section.To access this property, disable the Link Light Layer checkbox. |
Contact Shadows
This section is only available in Realtime or Mixed light Mode.
| Property | Description |
|---|---|
| Enable | Add Contact Shadows to this Light. Use the drop-down to select a quality mode for the Contact Shadows. Select Custom to expose a checkbox that allows you to enable or disable Contact Shadows at will. |
Baked Shadows
This section is only available in Baked light Mode.
| Property | Description |
|---|---|
| Enable | Enable the checkbox to let this Light cast shadows. |
| Near Plane | The distance, in meters, from the Light that GameObjects begin to cast shadows. |
High Filtering Quality properties
In your HDRP Asset, select High from the Filtering Quality drop-down to expose the following properties.
| Property | Description |
|---|---|
| Shadow Softness | Defines the behavior of area light shadows. Higher softness values mimic a larger emission radius while lower values mimic a punctual light. High values increase shadow blur depending on the distance between the pixel receiving the shadow and the shadow caster. |
| Blocker Sample Count | The number of samples HDRP uses to evaluate the distance between the pixel receiving the shadow and the shadow caster. Higher values give better accuracy. |
| Filter Sample Count | The number of samples HDRP uses to blur shadows. Higher values give smoother results. |
| Minimum Size of the Filter | The minimum size of the whole shadow’s blur effect, no matter the distance between the pixel and the shadow caster. Higher values give blurrier results. |
Real-time light cookies:
HDRP allows you to use a RenderTexture as a light cookie. However, for the sake of performance, if you make any changes to the RenderTexture, HDRP does not automatically update the cookie atlas. To notify the system that the RenderTexture content has changed and thus make the system upload the change to the cookie atlas, call IncrementUpdateCount() on the RenderTexture. If you do not do this, the system does not update the cookie.