Your game looks perfect in the Editor. Materials render correctly. Effects work as expected. Then you make a build — and suddenly some objects turn pink, render without effects, or lose important visual features.

This is often caused by missing shader variants in the final build.

Unity strips unused shader variants during the build process to reduce size and improve performance. Unfortunately, this sometimes removes variants that are actually needed at runtime.

What Are Shader Variants?

Modern Unity shaders generate multiple internal versions called variants. Each variant represents a different combination of keywords and features.

For example, a shader might have variants for:

• Shadows enabled or disabled
• Lightmaps on or off
• Normal maps enabled
• Fog enabled
• Different rendering paths

Unity only includes variants it believes are required. If a variant is triggered dynamically at runtime, it may not be included in the build.

Common Symptoms

• Pink materials in build only
• Particles missing effects
• URP features not rendering
• Post-processing missing in build
• Works in Editor but broken in build

Why Variants Go Missing

Unity strips shader variants when:

• A keyword is enabled via script at runtime
• A material is loaded dynamically (Addressables or Resources)
• Graphics settings do not include the shader
• Shader features are conditionally compiled

If Unity does not detect the variant during build analysis, it removes it.

Fix 1: Create a Shader Variant Collection

Unity allows you to explicitly record and include shader variants.

Steps:

• Open Graphics Settings
• Create a Shader Variant Collection asset
• Assign it in the “Preloaded Shaders” section

At runtime, you can warm up the collection:

using UnityEngine;

public class ShaderWarmup : MonoBehaviour
{
    public ShaderVariantCollection collection;

    void Awake()
    {
        if (collection != null)
        {
            collection.WarmUp();
        }
    }
}

This ensures required variants are compiled and included.

Fix 2: Add Shaders to Always Included Shaders

Go to:

Edit → Project Settings → Graphics

Under Always Included Shaders, add the shaders that disappear in builds.

This forces Unity to include all variants of that shader.

Be cautious. This can increase build size significantly.

Fix 3: Avoid Runtime Keyword Surprises

Enabling shader keywords dynamically can cause stripping problems.

Example:

material.EnableKeyword("_NORMALMAP");

If this keyword is never enabled during build analysis, its variant may not be included.

Solution:

• Use a material in the scene with that keyword enabled
• Include it via Shader Variant Collection

Fix 4: URP and HDRP Specific Settings

In URP:

• Check the URP Asset → Shader Stripping settings
• Disable aggressive stripping during debugging

In HDRP:

• Verify HDRP Global Settings
• Ensure required features are enabled in the pipeline asset

Pipeline settings directly affect variant inclusion.

Fix 5: Addressables and Resources

If shaders are used only inside Addressables or dynamically loaded prefabs, Unity may not detect them during build.

Solution:

• Include a reference material in a test scene
• Or use a Shader Variant Collection

How to Confirm It Is a Variant Issue

• Switch build target and compare behavior
• Disable shader stripping temporarily
• Add shader to Always Included and test again

If the problem disappears, it was a stripped variant.

Performance Considerations

Including too many variants increases:

• Build size
• Build time
• Memory usage

Do not disable stripping entirely in production. Instead, include only necessary variants.

Is This a Unity Bug?

Not exactly. Shader stripping is an optimization system designed to reduce unused shader combinations. The issue appears when runtime behavior does not match what Unity detects during build analysis.

Final Thoughts

If materials turn pink or effects disappear only in builds, suspect shader variant stripping first.

Use Shader Variant Collections carefully, manage keywords intentionally, and verify pipeline stripping settings. Once controlled properly, shader variant issues become predictable and preventable.