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Working with Tangent and Binormal Maps

The normal, the tangent, and the binormal are the three vectors at each vertex that define a coordinate frame on the surface of a geometric object. Conceptually, the U (tangent) and V (binormal) basis are supposed to be tangent to the surface, while the normal is perpendicular to the surface.

• The tangent is a vector in space that roughly corresponds to the direction of the texture u-coordinate (first coordinate) increase over the mesh.

• The binormal is a vector in space that roughly corresponds to the direction of the texture v-coordinate (second coordinate) increase over the mesh.

All by themselves, normals do not provide enough information to properly define the surface of an object. Tangents and binormals are necessary for accurate normal mapping and other realtime per-pixel effects such as bump mapping.

Without tangents and binormals...	With tangents and binormals...

Topics:

• Generating and Storing Tangents and Binormals.

• Applying Tangent and Binormal Properties.

• The Structure of Tangent and Binormal Properties.

• Editing Tangents and Binormals.

• Setting the Data Type for Tangents and Binormals.

Autodesk Softimage v.7.5     <     >