Available with 3D Analyst license.
When using 3D symbols in the Symbol Property Editor dialog box, some features specific to 3D become available that are common to all 3D symbols, such as a 3D preview, 3D placement, and 3D threshold. The Symbol Property Editor provides advanced display properties you can use to modify and maintain your symbols. You can also save symbols to styles and customize which styles you want to reference in your documents.
The ArcGIS 3D Analyst extension stores models in its styles with real-world sizes and attempts to provide sizing options for other symbols that will suit your needs. However, you might find that after you symbolize a feature, you'll need to adjust its scale in your document. In ArcGlobe, you can set symbol size based on distance from the globe using a layer properties setting. In ArcScene, the Scale 3D Symbols dialog box, accessed from a layer's context menu, allows you to do this using quick, on-the-fly feedback.
The ArcGIS 3D styles contain symbols with preset properties that you might use often. Geometric primitives, as well as model libraries, can be stored in the style. There are also other Esri-provided styles that are 2D.