User's Guide ‐ Updated Object Properties
Source Level Editor 2.104
The Wiki button (1) opens a URL on Valve Developer Community (VDC) by passing the class name as part of the address. In other words, if a page about the selected entity exists on VDC, it will open that page.
The Quick Access button (2) opens into a drop-down list of suggested classes to quickly change the selection into. These classes are chosen in the Options (see the user's guide section).
The Random Yaw button (3, partially obscured) sets the yaw (rotation around the Z axis) to an arbitrary value from 0 to 360. This is useful when putting down clusters of props and not wanting them to look too repepetive.
The Fire Once checkbox has been replaced with Times to Fire control (1). Outputs can be made to fire a chosen number of times before being removed from the entity (this is tracked by the game's code).
This system always existed in Source, and "Fire Once" simply meant using "1" as the limit, and "-1" as firing unlimited amount. As such, this change retroactively works with any game, not requiring game code changes.
The second Mark button (2) can be used for marking (selecting) entities passed as an argument for output parameter override.
For example, the output SetParent expects a name of the parent entity as the argument. The Mark button can locate that entity in the map, making checking outputs easier.
The biggest difference is seen in the revamped Model tab.
The Frame slider (1), previously non-functional, now can scroll through the model's animation length (the span is treated as 0-1 rather than frame-based like in HLMV).
The Play Animation checkbox (2) toggles realtime playback of animations.
The Activity readout (3) prints the name of the Activity associated with the sequence, similar to HLMV.
The Model data box (4) contains several readouts printing technical information: the full model path, internal version, triangle count, physical mass, and the surfaceprop.