To create a unique visual style in your sceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary, you can change the light falloff function in URP for real-time and baked lighting.
This example replaces the default URP light falloff function with a quadratic falloff function, which has a different visual style. You can modify the functions mentioned on this page to achieve other visual styles. The quadratic light falloff function has a similar behavior to the falloff function in the Built-In Render PipelineA series of operations that take the contents of a Scene, and displays them on a screen. Unity lets you choose from pre-built render pipelines, or write your own. More info
See in Glossary.
This customization requires modifying URP source code. For instructions, refer to Modify URP source code.
To modify the light falloff behavior for real-time lights:
Open the following HLSL file:
Packages/com.unity.render-pipelines.universal/ShaderLibrary/RealtimeLights.hlsl
Modify the DistanceAttenuation
method. Use the following code:
// The quadratic falloff function provides a visual style
// similar to the Built-In Render Pipeline light falloff.
float DistanceAttenuation(float distanceSqr, float2 distanceAndSpotAttenuation)
{
// Calculate the linear distance from the squared distance value.
float distance = sqrt(distanceSqr);
// Calculate the range of the light by taking the inverse square root of the attenuation parameter.
float range = rsqrt(distanceAndSpotAttenuation.x);
// Normalize the distance to a value between 0 and 1 (1 at the source, 0 at the max range).
float distance01 = saturate(1.0f - (distance / range));
// Apply quadratic falloff.
float lightAtten = pow(distance01, 2.0f);
// Smooth the falloff across the entire range for a more gradual and natural fade.
float smoothFactor = smoothstep(0.0f, 1.0f, distance01);
lightAtten *= smoothFactor;
return lightAtten;
}
Modify the AngleAttenuation
method. Use the following code:
float AngleAttenuation(float3 spotDirection, float3 lightDirection, float2 spotAttenuation)
{
// Compute the cosine of the angle between spotlight and surface.
float SdotL = dot(spotDirection, lightDirection);
// Linearly interpolate attenuation between the inner and the outer cone.
float atten = saturate(SdotL * spotAttenuation.x + spotAttenuation.y);
// Apply cubic smoothing for a gradual edge falloff.
atten = atten * atten * (3.0f - 2.0f * atten);
return atten;
}
The following illustration compares the default URP light falloff, the custom light falloff function in this example, and the light falloff in the Built-In Render Pipeline.
To ensure that the look of the baked lighting in your project matches the look of real-time lighting, change the light falloff of the baked lightsLight components whose Mode property is set to Baked. Unity pre-calculates the illumination from Baked Lights before runtime, and does not include them in any runtime lighting calculations. More info
See in Glossary.
Open the following file:
Packages/com.unity.render-pipelines.universal/Runtime/UniversalRenderPipelineCore.cs
Change the lightData.falloff
value to FalloffType.Legacy:
lightData.falloff = FalloffType.Legacy;
The value FalloffType.Legacy uses quadratic attenuation, which matches the real-time falloff in this example. You can use other values to match the real-time lighting in your project.
For more information on changing the light falloff function in baked lighting, refer to Change the fade distance of lights with fall-off
Did you find this page useful? Please give it a rating:
Thanks for rating this page!
What kind of problem would you like to report?
Thanks for letting us know! This page has been marked for review based on your feedback.
If you have time, you can provide more information to help us fix the problem faster.
Provide more information
You've told us this page needs code samples. If you'd like to help us further, you could provide a code sample, or tell us about what kind of code sample you'd like to see:
You've told us there are code samples on this page which don't work. If you know how to fix it, or have something better we could use instead, please let us know:
You've told us there is information missing from this page. Please tell us more about what's missing:
You've told us there is incorrect information on this page. If you know what we should change to make it correct, please tell us:
You've told us this page has unclear or confusing information. Please tell us more about what you found unclear or confusing, or let us know how we could make it clearer:
You've told us there is a spelling or grammar error on this page. Please tell us what's wrong:
You've told us this page has a problem. Please tell us more about what's wrong:
Thank you for helping to make the Unity documentation better!
Your feedback has been submitted as a ticket for our documentation team to review.
We are not able to reply to every ticket submitted.