The Properties dialog box is the primary method of modifying entity properties, and also allows you to adjust VisGroup properties for one or many brushes.
Class Info
The Class Info section is where you will modify entity properties. As is apparent from the above picture, there are two different modes you can be in, SmartEdit, and not SmartEdit (toggled by the button, circled). When you use the SmartEdit mode, all of the entity's keyvalue descriptions are shown to you. If you are already familiar with the entity properties, you may find it more convenient to turn this mode off and manually insert the keyvalues.
Flags
This section is also only available when editing an entity's properties. You will find listed here all the available flags for an entity. They can be toggled on or off.
Timeline
Timelines are Half-Life specific. They allow you to specify an exact period in hours and minutes when the selected entity will be in the level.
Related Topics:
• creating solids and entities