Displacement Mapping
 
 
 
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Material Editor Standard material Maps rollout Displacement button

A displacement map displaces the geometry of surfaces. The effect is similar to using the Displace modifier. Unlike bump mapping, displacement mapping actually changes the geometry of the surface or patch tessellation. Displacement maps apply the gray scale of the map to generate the displacement. Lighter colors in the 2D image push outward more strongly than darker colors, resulting in a 3D displacement of the geometry.

Using displacement mapping to alter a surface

WarningA displacement map generates many triangular faces per surface, sometimes over 1M faces per surface. While displacement mapping can create good effects, there is a large cost in terms of time and memory.

The displacement Amount is measured as a percentage of the diagonal of the bounding box for the object that contains the patch or surface. This makes the displacement effect consistent for all surfaces in an object, and it also means that when you scale the object, the displacement is scaled with it.

You can apply a displacement map directly to the following kinds of objects:

For other kinds of geometry such as primitives, extended primitives, compound objects, and so on, you can't apply displacement mapping directly. To use displacement mapping with these kinds of objects, apply a Disp Approx (Displacement Approximation) modifier. This makes the object's surface displaceable. Disp Approx works with any kind of object that you can convert to an editable mesh.

Displacement mapping isn't visible in viewports unless you apply a modifier to make it so.

Under certain circumstances, such as when the underlying mesh is fairly simple, displacement mapping of an editable mesh can cause problems because of the way the underlying mesh is tessellated. (These problems don't occur when you apply displacement mapping to a NURBS surface.) When this happens, smoothing does not work properly and you can see the underlying wireframe mesh in the surface itself. To correct this problem, use these techniques:

Procedures

To apply a displacement map to a NURBS surface, editable mesh, or patch:

  1. In a material's Maps rollout, click the map button for Displacement.

    The Material/Map Browser is displayed.

  2. Choose from the list of map types, and then click OK.

    The Material Editor is now at the map level, and displays controls for the map parameters.

  3. Use the map controls to set up the map.

To apply a displacement map to other kinds of objects:

  1. Select the object. Go to the Modify panel and choose Disp Approx from the Modifiers drop-down list.

    You can adjust the Disp Approx modifiers parameters, or you can leave them at their default settings.

  2. Open the Material Editor.
  3. In a material's Maps rollout, click the map button for Displacement.

    The Material/Map Browser is displayed.

  4. Choose from the list of map types, and then click OK.

    The Material Editor is now at the map level, and displays controls for the map parameters.

  5. Use the map controls to set up the map.

    For example, if you chose Bitmap as the map type, you now need to select the bitmap file to use.