Version: Unity 6 (6000.0)
Language : English
Optimize shadow rendering in URP
Reflections in URP

Troubleshooting shadows in URP

Techniques for troubleshooting shadow rendering in the Universal 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
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(URP).

Adjust the shadow bias settings in URP

By adjusting the shadow bias values you can reduce or eliminate such shadow artifacts as shadow acne, shadow detachment (also known as peter-panning), light leaking, and self-shadowing.

In URP, you can set the shadow bias in the URP Asset and on individual lights.

In the URP Asset, the shadow bias settings are in the Shadows section. The values you set here are the default values for all lights in the 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
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.

To set the shadow bias values for a specific light:

  1. In the Shadows section of the Light component, ensure that Shadows Type is set to Soft Shadows or Hard Shadows.

  2. Set the Bias property to Custom. Unity shows the properties Depth and Normal. Use those properties to set the shadow bias values for the current light.

Using high shadow bias values might result in light leaking through meshes. This is where there is a visible gap between the shadow and its caster, and leads to shadow shapes that do not accurately represent their casters.

Avoid shadow flickering caused by maximum light limit in URP

URP has the per-camera limit on the number of visible lights in the cameraA component which creates an image of a particular viewpoint in your scene. The output is either drawn to the screen or captured as a texture. More info
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frustum. For example, on mobile platforms, this limit is 1 Main Light and 32 Additional Lights.

In the Forward Rendering PathThe technique that a render pipeline uses to render graphics. Choosing a different rendering path affects how lighting and shading are calculated. Some rendering paths are more suited to different platforms and hardware than others. More info
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, there is also the per-object light limit.

If the number of visible lights exceeds the limit, Unity disables some lights. It might disable a real-time shadow-casting light, which causes shadow flickering.

To avoid this issue, ensure that the number of visible lights in the camera frustum does not exceed the limit. You can get the number of visible lights using the cullResults.visibleLights array of the RenderingData.cullResults API.

The following example shows how to use the cullresults.visibleLights array:

public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
{
    int visibleLightCount = renderingData.cullResults.visibleLights.Length;
}
Optimize shadow rendering in URP
Reflections in URP