Why does Unity LineRenderer not receive shadows from other objects?

Default LineRenderer uses an Unlit material which ignores lighting and shadows. Assign a Lit material (Standard or URP/Lit) and ensure Receive Shadows is enabled on the LineRenderer's Lighting tab.

How do I make a LineRenderer cast shadows?

On the LineRenderer, expand Lighting and set Cast Shadows to On. Combined with a shadow-supporting material, the line then casts. Performance cost is small for short lines but can be high for long meshes.

Why does my LineRenderer look unlit even with a Lit material?

LineRenderer geometry has no normals; lighting calculations need normals to work properly. URP/HDRP Lit handles this OK; Built-in Standard may need a custom shader that fakes normals or uses billboard lighting.

Fix: Unity LineRenderer Not Receiving Shadows

Quick answer: Assign a Lit material (URP/Lit, HDRP/Lit, or Standard) to the LineRenderer and enable Receive Shadows in its Lighting section. Default Unlit materials ignore lighting entirely.

Here is how to fix Unity LineRenderer that ignores scene shadows. The default sprite/unlit material does not respond to lighting; switching to a Lit material plus enabling shadow flags brings the line into the lighting model.

The Symptom

LineRenderer renders correctly but is unaffected by directional shadows or indoor light. Other meshes around it shadow correctly.

What Causes This

Unlit material. Default LineRenderer often uses Sprites/Default or Particles/Standard Unlit which skip lighting calculations.

Receive Shadows off. Even with Lit material, the renderer’s flag must allow shadow reception.

No normals on line geometry. Built-in Standard expects normals; LineRenderer billboards do not generate them naturally.

The Fix

Step 1: Assign a Lit material. Create a new material based on URP/Lit (or HDRP/Lit). Drop into the LineRenderer’s Material slot.

Step 2: Enable Receive Shadows. LineRenderer inspector → Lighting → Receive Shadows = true.

Step 3: Optional - cast shadows too.

Lighting:
  Cast Shadows:    On
  Receive Shadows: true
  Light Probes:    Blend Probes
  Reflection Probes: Blend Probes

Step 4: For Built-in pipeline custom shaders.

// Add to your shader pass
#pragma multi_compile_fwdbase
#include "AutoLight.cginc"

// In fragment
fixed shadow = SHADOW_ATTENUATION(i);
col.rgb *= shadow;

Custom Lit shaders for LineRenderer require explicit shadow attenuation sampling.

Step 5: Verify with shadow strength. Move the LineRenderer under a strong directional light and have a static cube above. Shadow should fall on the line. If not, the material is not actually receiving lighting.

“Lit material. Receive Shadows on. Possibly custom shader for Built-in. Lines join the lighting world.”

Related Issues

For LineRenderer UV stretch, see UV Stretching. For LineRenderer URP visibility, see Not Visible URP.

Lit material. Receive Shadows. Lights touch the line.