Left 4 Dead 2 Skin Selector (&RNG) (Users/Modders Guide)

Difficulty : 

❗ IMPORTANT : Despite its name, the Skin Selector is not only a Skin Selector. It can do everything that RNG codes are able to do. You do not need to choose between traditional randomization (RNG) codes and this, you can have both at the same time ! In other words, it is the next stem after the traditional RNG.

Short description : With the Skin Selector, the end user can change the skin of a compatible target using keyboard shortcuts. The Skin Selector can also randomize the skins, and includes all RNG codes in one easy new CORE MOD that does everything.

Needed skills to implement in a character or item mod :

• Knowing how to make a multiple frames VTF
• Knowing how to edit a VMT
• Having multiple textures for the user to select or to randomize (RNG)

These lines assign the controls to keys G / X / ENTER / the ARROW KEYS / , / . / M / N.
You can change these key codes if you want. To do so, you need to replace the word after bind (for example DOWNARROW) before you copy the line and press enter in the Console. A list of all the possible Key Codes can be found at the very end this Guide in an Appendix.

If you used the default key binds, these are the new controls you can use.
They are divided into four sets, a green one, a blue one, a red one, and a yellow one.

• [Green] : These are the keys used to “Grab” a compatible target
• [Blue] : These are the keys used to change the skin once a target is grabbed
• [Red] : These are special keys used if you want to grab a target that is on you (first person)
• [Yellow] : A special key used to grab the world. It grabs every target that is an object

• [ENTER GRAB MODE] (Default = G) : When pressed once, activates the “Grab Mode“. While in “Grab Mode“, compatible targets will become green when approached. When a target is green, it can be grabbed with the Grab key.
• [GRAB] (Default = X) : When a target is green because both “Grab Mode” is active and the user is near the target, pressing this key will grab the target and enable the skin selector.
• [EXIT] (Default = ENTER) : Locks the skin in place, exit the skin selector, and resets everything.
• [NEXT SKIN / PREVIOUS SKIN] (Default = LEFT / RIGHT ARROWS) : When a grab is secured, allows the user to change the skin (texture) of the selected part of the target.
• [NEXT BLOCK / PREVIOUS BLOCK] (Default = UP / DOWN ARROWS) : When a grab is secured, allows the user to switch between different parts of the target to change their skins independently, if the mod allows this.
• [HIDE / SHOW] (Default = , / .) : When a grab is secured, allows the user to hide or show the selected part, if the mod allows this.
• [ENABLE FP GRAB (CHARACTER)] (Default = N) : When pressed, allows the user to grab himself (the character he is playing).
• [ENABLE FP GRAB (ITEM)] (Default = M) : When pressed, allows the user to grab the item he is currently having in his hands.
• [WORLD GRAB] (Default = B) : When pressed, allows the user to grab every object in the world at once (that all share the same RNG) to change their skins.

Here is a step by step image tutorial on how to change the skin on a compatible (test) mod : Honoka from DOA5. It will teach you how to use the Skin Selector.

First, press on the [ENTER GRAB MODE] (Default = G) key to activate the Grab Mode.
Here, the Grab Mode is active, but we are too far from Honoka. We need to get closer.

When we get closer while in Grab Mode, the compatible Honoka mod will glow green. When a target is green, it means it can be grabbed.
Now you need to press [GRAB] (Default = X) to grab her and start the Skin Selector.

Right when you press the [GRAB] (Default = X) key, Honoka (or the target) will become black, except for the current selected part/block of her model. In this case, it’s her shirt.

By pressing the [NEXT SKIN / PREVIOUS SKIN] (Default = LEFT / RIGHT ARROWS), you can now change the skin of the selected part. Here, I ended up choosing one with a turtle design on it.

Maybe you don’t like her having a shirt, and you want to remove it. To do so, you can use the [HIDE / SHOW] (Default = , / .) keys to remove it. Here I pressed the HIDE key so her shirt disappeared. Note that not all clothes can disappear; it’s the modder that chooses. Also, you can notice that now, the shirt is still selected, but invisible.

If this bikini skin does not fit your likings, you can change it. By pressing the [NEXT BLOCK / PREVIOUS BLOCK] (Default = UP / DOWN ARROWS), you can reach the bikini, that will become colorful when it gets selected.

Here again, by pressing the [NEXT SKIN / PREVIOUS SKIN] (Default = LEFT / RIGHT ARROWS), you can now change the skin of the bikini. Here, I ended up choosing one with stripes.

Now you could again use the [NEXT BLOCK / PREVIOUS BLOCK] (Default = UP / DOWN ARROWS) to navigate between parts of Honoka and change or toggle them. Here, I ended up selecting her tights and pressing the HIDE (Default = , ) key to make them disappear.

When you are done, press the [EXIT] (Default = ENTER) key to lock the skin in place and reset the Skin Selector. Honoka is now ready to kick ass with your selected skin.

When you want to grab something that is in your hands or the character you are currently playing, just press the [ENABLE FP GRAB (ITEM)] (Default = M) since you want to grab an item in first person. If you wanted to grab your character, you should have pressed on the [ENABLE FP GRAB (CHARACTER)] (Default = N) key instead. Note that now, my gun is green even though I am in first person mode.

The next steps are the same. Just press on the [GRAB] (Default = X) key and the Skin Selector will start on the target you hold in your hands. Here I used the [NEXT SKIN / PREVIOUS SKIN] (Default = LEFT / RIGHT ARROWS) to switch to a black skin. When you are done, press the [EXIT] (Default = ENTER) key to lock the skin in place. This also resets the First Person Grab Mode.

When you want to grab something that is part of the map, like a Vending Machine for example, there is also a special step to do, which is Grabbing the world. Here, I am close to a Vending Machine that is a compatible target.

Just press on the [WORLD GRAB] (Default = B) key. While in this mode, every object in the map can be grabbed at once, no matter the distance between the player and the object. Note that objects that glow usually do not become very green.

The next steps are the same. Press on the [GRAB] (Default = X) key and the Skin Selector will start. You can then change every skin at once.

This whole section of this Guide is dedicated to Modders that want to implement the Skin Selector and RNG in their mods, or convert their RNG Mods to the Skin Selector. The Skin Selector is not only a skin selector, because it can do all what RNG does. In other words, if you already have an RNG mod, or want to make an RNG mod, just use the Skin Selector.

❗ IMPORTANT : The Skin Selector can do anything RNG does. If you are a modder and are reading these lines, you can forget everything about RNG (except maybe complex Model RNG). This is a fresh new start, easier to understand, easier to implement, with more powerful options, that includes everything at once.

There are 2 versions of the code. These are also the 2 new versions of RNG. You can forget every other name like True RNG, Real RNG etc. These are the 2 versions :

🅴 Entity Version : Can be used on anything that is an entity
🆆 World Version : Can be used on anything else

The main difference between Entity and World version is that every Mod that uses World version shares the same RNG. In other words, changing the skin of any target that uses World version will also change the skin of any other target that also uses the World version.

It’s easy. If you CAN use 🅴 Entity Version, you SHOULD use 🅴 Entity Version.
And you CAN use the 🅴 Entity Version on this :

• Characters (Survivors)
• Infected (Special and Common)
• Weapons (Guns / Melee etc.)
• Usable items (Medkits / Pills / Adrenaline / Molotov / Pipebombs etc.)
• Pickable items (Gascans / Propane tanks / Fireworks / Gnome etc.)
• Escape vehicles
• Ammo piles
• Objects that can move and that can block the player (TVs / Big Green File Cabinets etc.)

Using the 🅴 Entity Version on anything else will crash the game 🔥.

In other words, you will probably rarely use the 🆆 World Version, that is made only for static map objects. And let’s be honest, there are very few things in a map that people usually want to randomize that are not in the list above. Here is a shot incomplete list of items that need the 🆆 World Version :

• Vending Machines
• Billboards and Bus Stop Ads
• Cars, Trucks, Vans, Buses etc.
• Signs

Make sure to remove any RNG code and all the variables ($) that came with it before doing any of these steps (reverse the mod to how it was before adding the RNG).

Download this mod (you will need to tell your subscribers to download it too) :

Open a VMT file in your mod that do not need to have any randomization (RNG). In other words, a VMT that will not be able to change and that will not use the Skin Selector. In this VMT, add one } at the very end of the code.

Still in this VMT that do not need to have any randomization (RNG), replace…

… at the top of the VMT by this …

Still in this VMT that needs to have RNG (Randomization), look at this line…

… and REPLACE the 1 with the number of different skins (VTF frames) you have for that VMT.
For example, if you have 10 different skins for this VMT, write “10.0” like this

Note that the number of different skins you have is not the n° of the last frame of your VTF, because there is a frame 0. The number of skins is one more than the n° of the last frame of your VTF.

REPEAT STEPS 5 to 7 for every other VMT that needs to have RNG (Randomization). Once this is done, your mod is ready for a first test. But there are a lot of ways to improve the Skin Selector or the RNG, which the rest of this Guide is about.

At this point, you did the only steps needed to make the Skin Selector work with the most basic options. But you can do much better and customize the user experience even more. The next small sections will help you improve your mod with Skin Selector and RNG (Randomization) so it will be just perfect, and will offer the most customization options to your end user.

Most of the customization options are avaliable for the 🅴 Entity Version, but that’s usually the one you will be using anyway. Each one of these improvements can be done separately.

For the first step, you need to use your brain cells to identify how many parts of your model have to be randomized separately. For example, let’s say you are making a character mod, and these are the things that the user can change, each in a separate VMT.
– Cap (your character has a cap that the user can show or hide)
– Hair (your character has different hair colors that the user can change)
– Skirt (your character has a skirt that can change color or be removed)
– Belt (your character has a belt around her skirt that can be removed with the skirt)
– Shoes (your character has different skins for her shoes)

In this example, the Belt and the Skirt are linked, and should randomize together (it would be stupid that the belt and the skirt could appear separately). Since these two must be linked together, you would have 4 groups (Cap / Hair / Belt+Skirt / Shoes).

You then need to assign an ID to each of these groups, starting at 0. For example :
0 : Shoes (1 VMT)
1 : Skirt + Belt (2 VMTs)
2 : Hair (1 VMT)
3 : Cap (1 VMT)

For the best user result, try to make it so lower IDs are for clothes at the bottom of the character and higher IDs for clothes at the top of the character

Now that your brain grouped the clothes or whatever your model is made of, it is time to edit the code so it knows what goes with what. Do you see this in the VMT ? :

In every VMT, you need to replace the 0 by the highest ID you just thought about. This value will be the exact same in every VMT that has this value.

In my example, this would be 3, which is the highest ID (for the Cap), so in every VMT where there is this $maxVMTidNumber, it should be equal to 3.

The last step is to set the actual IDs for each of the VMTs that have Randomization (RNG) elements. Do you see this line that says this VMD id Number ? :

I think you guessed it, you must replace the 0 by the IDs you just assigned at STEP 1, for each VMT that have Randomization (RNG) elements. Usually, this value will be different, but for VMT that need to randomize together, it will be the same.

In my example, both the VMTs for the Skirt and the Belt would therefore have an ID of 1 like this :

Still in my example, the value in the Hair VMT would look like this :

Still in my example, the value in the Shoes VMT would not change and still look like this :

Once you have done that, the code will do the rest, and allow the user to switch between the blocks (parts) you just assigned.

Do you see this line in the VMT ? :

If you change the value to “1” like this, so the $bumpmap always is the same as the $frame.

Do you see this line in the VMT ? :

If you change the value to “1” like this, the randomizer will now allows this VMT to disappear.

Make sure the $thisVMTcanDisappear variable is set to 1 in both VMTs that need to swap.

Make sure the IDs of both VMTs that need to swap ($thisVMTidNumber) is the same (please refer yourself to the 🄴 🅆 Change skins separately section to learn about IDs)
For example, in both VMTs, you would maybe have :

In ONE of the two VMTs that need to swap, change the $invertAlpha value to 1 like this :

Now one of the two VMTs will have its $alpha work in reverse, and show when the user press on HIDE, and hide when the user presses on SHOW, which allows for VMT swap.

In the VMT you just modified at STEP 3, add this like to make sure the VMT is not visible at start :

Do you see this line in the VMT ? :

If you change the value to “1” like this, the randomizer will now only select one same skin for the whole map and the skin the user picks will always match the skin in hand.

Note that no matter this setting, if the user changes the skin using the skin selector, it will always match.

If you want, you can also turn the RNG (Randomization) off. For example, you could want to offer the user exotic hair color for your character, but not make them default, so you can turn off the randomization while still allow your user to choose between them.
Do you see this line in the code ?

If you change the value to “0” like this, it will turn off the randomization (RNG) for this VMT, but the user will still be able to use the Skin Selector to change the skin.