How the roughness map generator works
A roughness map tells the renderer how sharp or blurry reflections are — black is mirror-smooth, white is matte. This tool reads your image’s luminance as the starting point, then gives you contrast and invert controls to shape it. It runs entirely in your browser: no upload, no sign-up, no watermark.
Contrast and invert
Contrast pushes the rough and smooth areas apart — useful when a flat photo doesn’t show enough variation. Invert flips the convention: PBR roughness is white-rough/black-smooth, but if your source is a gloss or smoothness map (white-smooth), flip it. Unity’s metallic-smoothness workflow wants the inverted version; Unreal and Blender want standard roughness.
Want roughness that matches the rest of the material?
A roughness map from luminance is an approximation. CraftPBR Studio derives roughness alongside albedo, normal, AO and metalness so they all agree. Free to try.
Open Studio →Related tools
Frequently asked questions
How do I make a roughness map from an image?
Drop an image into the tool. It converts the image to grayscale luminance — the basis of a roughness map — and lets you adjust contrast and invert the values. Lighter areas read as rougher, darker as smoother (or flip it with Invert). Download the PNG and plug it into your material’s roughness slot. Everything runs in your browser.
Should a roughness map be inverted?
It depends on your source and engine. In a standard PBR roughness map, white = rough and black = smooth. If your source reads the opposite way — or you exported a smoothness/gloss map — toggle Invert. Unity uses smoothness (the inverse of roughness), so a map authored for Unity’s metallic-smoothness workflow is inverted relative to Unreal/Blender.
Why must a roughness map be linear, not sRGB?
A roughness map stores data, not colour. If the engine gamma-corrects it as sRGB, your reflection sharpness shifts. Import it as Non-Color / linear data. The output here is a plain grayscale PNG — set the colour space to Non-Color on import.
Is this roughness map generator free?
Yes — free, no sign-up, no watermark, no upload. It runs entirely in your browser. For a full PBR set where the roughness is derived to match the albedo and normal, use CraftPBR Studio.