Custom fall-off

In the real world, light fades over distance, and dim lights have a lower range than bright lights. The term “fall-off” refers to the rate at which light fades. Alongside Unity’s default fall-off lighting behaviour, you can also use custom fall-off settings.

Progressive Lightmapper provides custom fall-off presets, which you can implement via script. See the image below the table for a visual representation of how these work, and the code sample below the image for an example of how to use this functionality.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Experimental.GlobalIllumination;
using UnityEngine.SceneManagement;

[ExecuteInEditMode]
public class ExtractFalloff : MonoBehaviour
{
    public void OnEnable()
    {
        Lightmapping.RequestLightsDelegate testDel = (Light[] requests, Unity.Collections.NativeArray<LightDataGI> lightsOutput) =>
        {
            DirectionalLight dLight = new DirectionalLight();
            PointLight point = new PointLight();
            SpotLight spot = new SpotLight();
            RectangleLight rect = new RectangleLight();
            LightDataGI ld = new LightDataGI();

            for (int i = 0; i < requests.Length; i++)
            {
                Light l = requests[i];
                switch (l.type)
                {
                    case UnityEngine.LightType.Directional: LightmapperUtils.Extract(l, ref dLight); ld.Init(ref dLight); break;
                    case UnityEngine.LightType.Point: LightmapperUtils.Extract(l, ref point); ld.Init(ref point); break;
                    case UnityEngine.LightType.Spot: LightmapperUtils.Extract(l, ref spot); ld.Init(ref spot); break;
                    case UnityEngine.LightType.Area: LightmapperUtils.Extract(l, ref rect); ld.Init(ref rect); break;
                    default: ld.InitNoBake(l.GetInstanceID()); break;
                }

          ld.falloff = FalloffType.InverseSquared;
                lightsOutput[i] = ld;
            }
        };

        Lightmapping.SetDelegate(testDel);
    }

    void OnDisable()
    {
        Lightmapping.ResetDelegate();
    }
}

Progressive Lightmapper added in 2018.1 NewIn20181

2018–03–28 Page published with limited editorial review