Available with 3D Analyst license.
You can create a TIN surface from one or more types of input data, you can create it in stages, or you can add data to refine an existing TIN surface model. TINs are made from mass points, breaklines, and polygons.
TIN components are built from input vector data, which represents different surface features. You can add vector data using both the Create TIN and Edit TIN tools. Use the Create TIN geoprocessing tool to construct a new TIN on disk. Once the TIN is created on disk, use the Edit TIN geoprocessing tool to add additional vector data to the new TIN.