Stripper:Source Guide (Advanced)

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Contents

Preface

This guide will cover the uses of Stripper in more depth, explain how various entities and mapping elements work and where to use them, practical applications of using Stripper to modify maps, advanced techniques, and how to resolve potential problems or work around Stripper's limitations.

It is highly recommended to read Stripper:Source Guide - Basics first to familiarize yourself with the fundamentals of Stripper, its structure, and its terminology.

Knowledge of Source engine and its entities, and Hammer Editor will also be useful, though not required when starting out.

Ideally, the decompiled versions of Valve's maps should be used for reference and to author your changes before transferring them into Stripper, as for more advanced modifications, relying entirely on Stripper dumps and in-game coordinates/entity placement will not be enough.

Standard Entity Properties

Entities in the Source engine share a standard set of properties that define key information about each individual instances of the entity.

Almost all entities have these properties, though for some they do not support every property, or it is not relevant to some specific entities. Many entities have their own unique properites which will be covered in later sections.

As mentioned in the basics guide, each property in Stripper is defined by a pair of strings, the key and the value. The key is the name of the property, and must be exact (though case is ignored), and the value can be any valid type of value for that key.

The Valve Developer Wiki is the best resource for finding these properties, along with accurate explainations of what they do and what values they accept. This information is also available in the Hammer Editor.

It can also be useful to look in Stripper dumps for the properties of specific entities, to see exactly what they use in-game.

Standard Properties

• classname
• targetname More info on different types of targetnames can be found here.
• parentname
• hammerid
• origin
• angles
• spawnflags
• model - Model has two distinctly different values. One is the file path of a model, used to select the model for a prop_ entity. The second is a precached brush model for brush entities (e.g. trigger_once), this is an * followed by a number (e.g. *51)
• solid
• StartDisabled
• disableshadows

Entity Inputs & Outputs

All non-static entities are capable of receiving inputs from other entities, and sending outputs to other entities. I/O is a shorthand way of referring to Inputs/Outputs.

The inputs and outputs of each entity varies depending on its type, though there is a standard set that all entities share. There are many I/Os that are also shared between many standard and L4D2-exclusive entities.

This input and output system how entities interact with each other in maps. It is the main method for scripting events and actions in Source engine maps, in L4D2 it is used heavily for things players interact with directly, and things that happen around them in the background. It is a very powerful system that has many possible uses beyond the scope of Stripper's three main functions.

The system works by having one entity send an output upon specific events, another entity can then receive that input and perform an action. For example, when a door is opened, it has an output to make a light entity turn on. An input is just another entity's output.

For a more detailed explaination of how this system works, read this article on the Valve Developer Wiki. A full overview of the system can be found on I/O System category page.

I/O Syntax

The I/O system has two parts, the event which causes the output to fire, and the actual parameter that defines what the output does.

The event types that can be used depend on the entity the output is fired by, these events can occur through players interacting with the game, or by other entities firing outputs.

For example, a prop_door_rotating can use OnOpen as an output event. This could fire when a player manually opens a door, or when the door receives an Open input from another entity.

The output parameter defines what an output does. Technically, these are multiple separate values, but for Stripper's purposes they are all in a single string, separated by commas.

NOTE: In Stripper dumps, this will be the unicode escape character u001b instead, which depending on the text editor used may not be displayed. It can be replaced by a comma without issue. It is recommended to use a source code editor such as Notepad++ for Stripper.

The values defined in the parameter are:

• Target Entities Named - Name of the entities to apply the output to. This can be either the targetname or the classname, and it will apply to all entities that match. An entity CAN target itself with an output. Special entity names can be used too, as seen here.
• Via This Input / Input Name - Name of the input to fire on the selected entity. The inputs available will depend on the type of entity targeted. The input selected will cause the entity to change that property or perform an action, such as changing color.
• Parameter Override - Specifies additional arguments for the input, meaning different values can be given for an input if applicable.
• Delay This Input - Delay in seconds before this input is fired by the target entity, from when the output is triggered. Can be a non-integer value.
• Fire Only Once - Number of times the output can be fired. -1 is infinite (no limit), and is the default.

More information about these values can be found here.

Usually, an entity will have an output type for any input that can be fired for it, so when an input is fired it can be followed up with an output by that entity. Though this is not the case for all inputs on all entities.

Together, the event and the parameter will create a single key-value pair like this:

;    Event                               Parameter String                            
"[Output Name]" "[Target],[Input Name],[Parameter Override],[Delay],[Fire Only Once]"

; --- Example of I/O system in use on an entity
add:
{
	"classname" "func_button"
	"origin" "2048 5706 2884.89"
	"model" "*5"
	; When the button is pressed, wait 3 seconds, then tell the director to spawn a panic event horde
	"OnPressed" "director,ForcePanicEvent,,3,-1"
}

Useful Entities