Why does Unity reset sRGB on a normal map?

If Texture Type is Default, Unity defaults sRGB to On and reapplies it on every reimport. For normal maps and data textures, set Texture Type to Normal Map or Default with sRGB unchecked — but be aware that the ‘Default’ type doesn’t persist sRGB if other settings change. Use Texture Type = Normal Map for normals and Texture Type = Sprite (2D and UI) for UI; both set the sRGB flag correctly for their data.

What happens if I mark a normal map as sRGB?

The GPU applies a gamma-to-linear curve when sampling. Normal vectors encoded in 0–255 channel space (the standard format) become distorted — specifically, the smaller components get pushed toward zero. Visually, surfaces look flatter and lighting shifts to a noticeable degree on metallic and specular materials.

How do I bulk-fix imported textures?

Write an AssetPostprocessor that runs OnPreprocessTexture, inspects the asset path, and forces the correct Texture Type. Place it in an Editor folder; it runs every time a texture is imported, ensuring all _N (normal) and _D (data) textures get the right settings regardless of how they arrived in the project.

Fix: Unity Texture Import sRGB Flag Wrong After Reimport

Quick answer: Set Texture Type explicitly — Normal Map for normals, Default with sRGB unchecked for data textures. Add an AssetPostprocessor that enforces the type based on file name suffixes.

After a team member checked in updated normal maps, the next person to reimport noticed their normals had subtle wrong lighting. The .meta file said sRGB was checked. They unchecked it, the lighting looked right, they committed, and a week later it happened again to someone else.

How Unity Decides sRGB

The Texture Importer’s Texture Type dropdown sets a category that determines how Unity treats the texture data:

Default: sRGB toggle is editable. Defaults to On if the source has 3+ channels.
Normal Map: sRGB is forced off, channels are interpreted as DXT5nm or BC5 normal, swizzles applied automatically.
Sprite (2D and UI): sRGB forced on (UI is color data).
Lightmap: HDR-specific, sRGB forced off.
Single Channel: data-only, sRGB forced off.

If a normal map is set to Default, sRGB can be toggled by hand but Unity may flip it back during reimport — particularly if the source file changes dimensions or channel count. The fix is to set Texture Type to Normal Map, which removes the toggle entirely and locks the linear interpretation.

The AssetPostprocessor Solution

For project-wide enforcement, add an Editor-only script that classifies textures by filename suffix:

using UnityEditor;
using UnityEngine;

public class TextureImportRules : AssetPostprocessor
{
    void OnPreprocessTexture()
    {
        var importer = (TextureImporter)assetImporter;
        string path = assetPath.ToLower();

        if (path.Contains("_n.") || path.Contains("_normal."))
        {
            importer.textureType = TextureImporterType.NormalMap;
        }
        else if (path.Contains("_d.") || path.Contains("_data.") ||
                 path.Contains("_mask.") || path.Contains("_rough."))
        {
            importer.textureType = TextureImporterType.Default;
            importer.sRGBTexture = false;
        }
        else if (path.Contains("_ui."))
        {
            importer.textureType = TextureImporterType.Sprite;
        }
    }
}

Place in Assets/Editor/. The script runs every time Unity imports or reimports a texture. Filename conventions become the source of truth, and individual .meta tweaks no longer drift.

Force a Project-Wide Reimport

To apply the new rules to existing textures, reimport them:

// Editor menu: Tools → Reimport All Textures
[MenuItem("Tools/Reimport All Textures")]
static void ReimportAll()
{
    var guids = AssetDatabase.FindAssets("t:Texture2D");
    foreach (var guid in guids)
    {
        var path = AssetDatabase.GUIDToAssetPath(guid);
        AssetDatabase.ImportAsset(path, ImportAssetOptions.ForceUpdate);
    }
}

Run after committing the AssetPostprocessor. Commit the resulting .meta changes — they encode the corrected import settings.

Verifying

Pick a known normal map. Open the Inspector. Texture Type should read “Normal Map”. Open the .meta file in a text editor (it’s YAML); look for sRGBTexture: 0. If it says 1, the rule didn’t match the filename pattern — check the suffix convention.

Compare a material with the normal map before and after the fix. Subtle but distinct: post-fix normals show crisper micro-lighting, especially on metallics where the energy conservation depends on accurate normal data.

What About Existing Misnamed Files?

If your project has normal maps named rock_bump.png instead of rock_n.png, either rename them (Unity rewrites references on rename), or add label-based classification:

AssetDatabase.SetLabels(asset, new[] { "NormalMap" });
// then in the importer:
if (AssetDatabase.GetLabels(importer.GetAsset()).Contains("NormalMap")) ...

Labels survive renames and are project-wide visible.

“Manual sRGB toggles drift. AssetPostprocessor rules don’t. Encode the convention once; let the importer enforce it forever.”

Lock the Texture Type, not the sRGB toggle. Type is the durable setting; sRGB is its consequence.