Limited support
This feature is only present in Portal 2: Community Edition and Portal: Revolution.

sv_debug_draw_contacts

🟦 Executable on Client

sv_debug_draw_contacts <value>

0: Dont draw anything. 1: Draw contacts. 2: Draw colored contacts

Warning:

This is a cheat command and can only be used when sv_cheats is set to 1.

Note:

The value is synced between the server and all clients.