In Layer style 
, for 3D object layers and polygon layers with 3D styles, click the Edges toggle button to accentuate and stylize the building edges and outlines, including substructures, exterior walls, balconies, and roofs.
To use Edges, do the following:
- Click the Edges toggle button to turn edges on and off in your layers.
- For Style, choose the style of the lines defining your edges.
- solid—Solid straight line
- sketch—Hand-drawn sketched line
- <custom>—Custom-styled line only available when saved from another app, such as ArcGIS Pro
Note:
If <custom> is selected, the Color and Size options are unavailable.
- For Color, choose either light or dark for the edge lines.
- For Size, choose thin, standard, or thick for the thickness of your lines.