How to Create a 3D Bump Map Using Photoshop

Prepare textured maps to become 3D models in Photoshop CC

Bump map

Robin_Hoood / Getty Images

Bump maps are used in 3D modeling to artificially create textured surfaces without having to model the individual details. All 3D bump maps start out as 2D drawings, so before you open your modeling software, you should prepare the bump map image in Photoshop.

Instructions in this article apply to Photoshop CC 2019 for Windows and Mac.

What Are Bump Maps?

Bump maps are layered under full-color painted texture maps and use grayscale to instruct 3D modeling programs on how far to extrude polygonal surfaces. Black represents the highest extreme of extrusion, white represents the flattest areas, and shades of gray cover everything in between.

Rather than you having to manually choose every little bump on your model, a bump map automates the process. It tells the 3D program to change the polygons in relation to your bump map procedurally, which reduces the load on computer resources when it renders the model.

For example, if you were texturing a lizard's skin, a bump map for the skin could use a mid-level gray as a baseline for the skin surface, with white for the deepest cracks and darker gray spots for the raised areas. You can even use a bump map to make facial highlights and shadows seem more realistic, or add details such as folds and wrinkles to a model's clothing.

How to Prepare Bump Maps in Photoshop

For best results, use a map with a considerable amount of shading to simulate texture:

  1. Open your 2D texture map, or create one in Photoshop.

    You can use layer styles such as pattern overlay to generate repeating textures.

    A textured map of the world in Photoshop
    Frank Ramspott / Getty Images 
  2. Select Image > Mode > Desaturate.

    If you've generated your texture using layer styles and pattern overlays, you may need to flatten the layers.

    Select Image > Mode > Desaturate.
  3. In the bump map, lighter areas are interpreted as flatter while darker areas are interpreted as higher. Therefore, depending on how the image is shaded, you may need to invert the colors to produce the desired result. To do this, select Image > Adjustments > Invert.

    select Image > Adjustments > Invert if you need to invert the colors.
  4. Select Image > Adjustments > Brightness/Contrast.

    Select Image > Adjustments > Brightness/Contrast.
  5. Set the Contrast to 100 to increase the contrast between lighter and darker areas, then select OK.

    Set the Contrast to 100 to increase the contrast between lighter and darker areas, then select OK.
  6. Select File > Save As and save the map in a format that is compatible with your 3D modeling software.

    Select File > Save As and save the map in a format that is compatible with your 3D modeling software.

Once you've created your bump map, all you need to do is import it into your 3D animation program. Different 3D graphics programs have different ways of integrating bump maps into a model or polygon surface. The controls for the bump map should allow you to define a range to make sure the raised textures and depressions don't extrude to extremes, or scale down so small that they hardly show.

While it's possible to create 3D maps directly in Photoshop by going to Filter > 3D > Generate Bump Map, the result won't look nearly as good as what a 3D program can produce.