Texturing & materials · Beginner

Bump map

A grayscale texture that fakes fine bumps through shading alone

What is a bump map?

A bump map is a grayscale texture that fakes small surface detail: light areas read as raised and dark areas as sunken. The renderer shades the surface as if it had that texture, while the real geometry stays flat. It is the simplest way to add fine detail.

Think of it like this

It is like a photo of embossed wallpaper: the pattern seems to catch the light, but the photo itself is perfectly flat.

Where it fits in a 3D project

  1. Create
  2. Surface
  3. Rig
  4. Animate
  5. Render
  6. Export

Surface: Giving the shape its color and material: UVs, textures and shaders.

Base colorNormalRoughnessMetallicHeightMaterial
The height map is one of several texture maps a material combines.

How a bump map works

  1. 01Paint or generate a grayscale image where brightness means height.
  2. 02The renderer compares neighboring pixels to see which way the surface slopes.
  3. 03It shades each point as if it tilted that way, creating fake bumps.

Bump map vs normal map

PropertyBump mapNormal map
StoresHeight in one gray channelDirection in three color channels
Made byPainting by hand, easilyUsually baking from a model
DetailGood for fine, small detailMore precise, handles steeper slopes
Common inQuick setups and offline rendersGames and real-time engines

Reach for a bump map to add quick pores or grain; use a normal map when detail has to hold up in a game engine.

Where a bump map is used

  • Skin pores, fabric weave and paper grain
  • Quick surface detail without any baking
  • Small scratches layered on top of a normal map

Beginner tip

Keep the strength low. Bump maps look convincing at small scales and turn into a cheap embossed look when pushed too far.

Terms related to a bump map

Bump map FAQ

How does bump mapping work?
The renderer reads the brightness of nearby pixels to work out a slope, then tilts the shading at that point. Nothing moves, so the outline of the object stays smooth even when the surface looks rough.
What is the difference between bump and displacement maps?
A bump map only changes shading, so the shape stays flat. A displacement map moves the surface for real, changing the outline and casting true shadows, at a much higher cost in geometry.
Can I turn a bump map into a normal map?
Yes. Most texturing tools and many 3D apps convert a grayscale bump or height image into a normal map in one step.

Updated October 29, 2026 · Browse all 3D terms