Quote from sicklebrick on November 11, 2013, 1:08 pm

Just for fun I was tracing through Portal2's keypair parser and found a bunch of interesting undocumented functions you can play with. Some like rendercolor have been around since the early days, and other seem to be specific to Portal 2. I can't guarantee their usefulness or how dependable they are, but it's just a bit of fun.

Addoutputs:

Use from console like: ent_fire !player addoutput "rendercolor 255 0 0"
Or in hammer like: OnWhatever, !player, addoutput , rendercolor 255 0 0
//Don't use quotes in hammer.

"RenderColor"
-Changes the colour (yes colour!) of most entities during play
-Format: Red (0-255) Green (0-255) Blue (0-255)
-ent_fire !picker addoutput "rendercolor 0 255 0" is blue for example

"MoveType"
-Changes the player's movement type, not all values are valid, but it's good fun.
-Format: MoveType (0 - ~14)
- 0= stuck
- 1= normal
- 2= normal
- 3= stuck
- 4= floating like ExFu glitch (no speed limit)
- 5= can move backwards, and that's about it
- 6= normalish
- 7= stuck
- 8= noclip (without noclip console command)
- 9= normalish
- 10= stuck
- ...

"BaseVelocity"
-Sets the player's movement speed to these values:
-Format x,y,z (positive Z is up)
-ent_fire !player addoutput "basevelocity 0 100 2000"

"View_Ofs"
-Offsets your player model and camera from the physical player object
-I.e. player can be against a wall, and cam/gun can be through it or elsewhere
-Format x,y,z

"gravity"
-Changes the player's gravity scale - player only
-Format: 1 is normal scale, 0.1 is a tenth, 100 is 100 times, etc.

"solid"
-Changes the player or an object's solidity, alllowing you to clip through.
-Objects will fall through the ground and die.
-Format: 0=nonsolid, 1=solid

"modelscale" (old)
-Changes the scale of any given model, i.e. a companion cube.
-Does not affect physmodel, and often requires weird triggers before you can see
-changes (e.g. picking it up)
-Format: x,y,z (1,1,1 is default)

"spawnflags" (old)
-Changes the bimask of the flags you see in the hammer editor
-(last tab with checkboxes)
-Format: Different for most things
-Example: ent_fire !picker addoutput "spawnflags 256" will make most things carryable

"modelindex" (old)
-Changes the model of an object to a given index.
-It'll pick from the list of currently loaded objects, i.e. 1 is usually your ASHPD.
-Format: ent_fire !picker addoutput "modelindex 1"

Other unknowns, or ones I didnt check:

"texframeindex"
-Probably changes the frame of the texture on a given object.

"target"
-likely a generic entity for NPC's, faith plates, etc

"waterlevel"
-seems to make no odds in Portal 2

"ltime"
-beats me

"avelocity"
I assume it's angular velocity, but doesn't seem to make any difference.

Missing and incomplete entities:
(Warning -can be crashy)

Use with "ent_create mortarshell" for example

mortarshell
- Crashes game. Seems to be a throwback from HL2.
- Message = Debug string: Unable to load sprite material materials/sprites/physbeam.vmt!
- Message = Debug string: PrecacheScriptSound 'Weapon_Mortar.Impact' failed, no such sound script entry

spraycan
-You can 'spawn' it, but there's no model and it vanishes instantly
-i.e. you can't find or rename it afterwards

env_ragdoll_boogie
-Right?! I want this, seems to be an old one, but I want it.

weapon_paintgun
-Not spawnable, but it's referenced in the game binay maybe a dozen times.
-Also in the FGD (hammer) IIRC.

NPC_hoverturret
-Not spawnable

You can find a few more via dumpentityfactories for yourself.

I was going to end this with a few undocumented vscript functions, but none of them seem to do a damn thing, so lemme know if you find any