GLOSSARY

Mapping Coordinates

Decoration on the vase is a map positioned by rotating the UV Map Modifier gizmo.

Mapping coordinates specify the placement, orientation, and scale of a map on the geometry.

If you apply a mapped material to an object without mapping coordinates, the Renderer assigns default mapping coordinates. In 3D Studio MAX, there are three ways to apply mapping coordinates:

• Set the Generate Mapping Coords. option in the creation parameters rollout of any standard primitive. This option provides mapping coordinates specifically designed for the primitive. Because mapping coordinates require additional memory, you only turn them on when you need them.
• Apply a UVW Map modifier. You choose from several types of mapping coordinate systems and customize the placement of the mapping coordinates on the object by positioning a mapping icon. In addition, you can animate the transformations of the mapping coordinates.

The built-in mapping coordinates are designed for each object type. The box mapping coordinates place a duplicate map on each of its six sides. For the cylinder, the image is wrapped once around its sides, and duplicates of the image are distorted at the end caps.

A sphere has the image wrapped once around the sphere, and then gathered at the top and bottom. Shrink-wrap mapping is also spherical, but truncates the corners of the map and joins them all at a single pole, creating only one singularity.

• Use special mapping coordinate controls for special objects. For example, Loft objects provide built-in mapping options that let you apply mapping coordinates along their length and around their perimeter.

Assuming you’ve applied a mapped material to an object, there are three cases where you don’t need mapping coordinates:

• Reflection/refraction maps and environment maps don’t need mapping coordinates. They use an environmental mapping system, in which the placement of the map is based on the rendered view, and fixed to the world coordinates in the scene.
• 3D procedural maps (such as Noise or Marble) don’t need mapping coordinates because they’re procedurally generated, based on the local axis of the object.
• Face-mapped materials don’t need coordinates because the maps are placed based on the facets in the geometry.