Displaying features in ArcScene
When you add a layer to ArcScene, features with 3D geometries (for example, pointZ, polylineZ, polygonZ, and multipatch shapes) are automatically drawn in 3D, but you could have other 2D data sources you need to visualize in 3D that do not have z-values defined. To view 2D features in 3D, you need to define their z-values. You might also want to override the z-values within 3D features and display them using another method.
The default behavior when adding 2D features into ArcScene is to assign a constant height value of zero.
Defining base heights for layers without 3D geometry is a layer property setting in ArcScene on the Base Heights tab. There are two ways to set the base heights of features in 3D:
Another way to create 3D symbology is to extrude flat geometries into 3D shapes. Using extrusion as 3D symbology provides a simple method of creating three-dimensional objects from 2D features. Points can be extruded into vertical lines, polylines can be extruded into vertical walls, and polygons can be extruded into 3D solids.
You can combine base height and extrusion settings within ArcScene. For example, you could drape building footprints over an elevation surface, then extrude them by a height attribute to create a realistic city 3D view, all without requiring 3D features.