User Guide

Introduction

This guide will cover everything you must know about using the addon in Blender. It shows download and installation, use cases, and will also tell you a bit of game background knowledge.

Versioning

Current Version	For
1.0	User Guide
1.0	Addon for Blender version 2.8
1.0	Addon for Blender version 2.79

This guide uses addon version 1.0 for Blender 2.8.

Installation

The addon can be installed like any other addon in Blender. We will use the Install Add-on from File method. This method uses a special panel in Blender to read a .zip file.

First download the addon. Leave the downloaded file unzipped and open Blender. In the menu bar of Blender click Edit - Preferences.

In the sidebar click the Add-ons tab and after that click the Install button on the top right.

In the file dialog point to your downloaded .zip file, then click the Install Add-on from File button.

The addon is now installed, but it needs to be enabled. Search for the addon by typing rtcw in the search field. Toggle the checkbox to enable the addon.

Blender 2.8 by default saves your preferences, but to make sure we check for it. Otherwise the addon will not load on the next start of Blender.

First Steps

In this chapter an overview of the addon, as well as an import and export example is given. If you work yourself through this chapter, you will have seen almost everything about the addon.

Overview

The addon is located in a Panel called RtCW/ET in the View Properties of the 3D view port (shortcut 'N'). It will be available in Object Mode only.

Note: for Blender 2.79 it is located in the toolbar (shortcut 'T'). The Sub-Panel 'Shading' is not supported.

There are 5 Sub-Panels: Import, Export, Direct Conversion, Attachment, Shading and Unzip PK3s. You can find more details about those panels in chapter Panel Description.

Additionally the addon prints verbose log output to the system console. It will print debug, info and warning messages. You can open the system console under Window - Toggle System Console.

In case the addon receives too many warnings, it will redirect you here.

Import of a Character

In this section we are going to import and assemble a game character from the game Wolfenstein: Enemy Territory. Game characters are made up of many different parts. The main parts are: body, head, helmet and accessoires like the backpack. These parts are stored in different model formats: MD3 or MDC for head, helmet or accessoire models; and MDS or MDM/MDX for the body models.

Preparations

Before we start we should do 2 things: 1) extract the game data from pk3 files and 2) find out where our different model parts are located on disk.

Extracting the game data

At some point in this example (during shading or attachment) the addon needs to have a reference to a directory which contains all the game data in uncompressed form. Game data for RtCW and W:ET is mostly located in compressed files whose names end with .pk3.

We use the Unzip PK3s panel to extract all the .pk3 files from the game. See chapter Unzip PK3s for more details. For the input field called Source Filepath search for your W:ET installation path and choose the directory called etmain. For the input field called Target Filepath create a new and empty folder and use this as input.

Make sure enough space is left on your disk, as the operation will require around 800MBs. Click the Unzip button and after some time your data will be extracted to your target folder. The operation will search the source directory and all its subdirectories recursively and extract all .pk3 files it finds to the target directory.

Finding the model parts

W:ET uses a system involving .char files to assemble its characters during runtime. The .char file for the allied engineer is located at: characters/temperate/allied/engineer.char. The file content reveals some information:

The information is either directly containing a reference to the model files (see mesh or hudhead key) or it references other script files (for example animationgroup). The picture above marks the information needed for the body model and the head model. That will be our starting point.

Importing the body

The body models in W:ET are stored in two seperate files. The mesh data for the body is located in .mdm files. The animation data is separated and stored in .mdx files. This way different meshes can reuse the same animation data. This is different compared to RtCW, as RtCW stores all its data for a body model in a single .mds file.

We already have the location of the body file for our allied engineer, but we still need to figure out where its animation data from the .mdx files is located. We can find this information by following the animationgroup key-value pair from the .char file. Opening the file located at animations/human_base.anim reveals many different .mdx locations for this character. We choose body.mdx for this example as it is basically the main animation file used by all 10 characters of the game.

Now we have all the file paths we need for the body part. All that is left to do is use the Import Panel of the addon to import the model. Chapter Import has more details on this panel. After you located the panel in Blender, use the combo box called Format to choose the MDM/MDX file format.

For the input field called MDM Filepath choose its absolute path. For the input field called MDX Filepath choose its absolute path. Lastly, choose frame 32 for the input field called Bindpose Frame. This frame influences the edit mode mesh, which is bound to the skeleton. This is kind of a magic number. The models shipped with the game usually have many different frames representing the bind pose.

Your input fields should look similar to the picture above. Click the Import Button and after around 5 to 10 seconds (it is alot of data) your body model will be placed inside a collection in Blender. Make sure you have around 150 MB space left on disk, as the .blend files get rather large if you save them.

Importing and attaching the head

From chapter Finding the model parts we know the location of our head model. Let's fill in the data into the import panel for the MD3 format. This works the same as in the previous chapter. After import the head model will be placed into a separate collection.

For attachment of the head model to the body model we need to use a little magic again, as this information is hard coded in the source code. During run time, the game will load a lot of information for attaching the models onto special places of other models. These places are called tags. Our magic information tells us that there is a tag called tag_head on the body model. Tags are represented as empties with the prefix tag_ and display type ARROWS within Blender. Let's go into the collection for the body model and find this tag, just so we see how it looks like.

There are 3 kind of tags within the model formats. This one is attached to a bone with an offset. But there are also tags for bones without an offset and tags without any parent. We will attach the head model to this tag object by using the Attachment Panel. As the method for attachment we choose Collection.

The method we chose attaches the objects within a selected collection to an active tag object. First deselect everything, then select the collection for the head model and then select the tag object called tag_head to make it active. It is important that you select the tag object last, as only the active object will be considered a tag object by the addon. Click the Attach Button. The result is that all objects of the collection (our head collection) will be parented (or attached) to the tag object.

Importing and attaching accessoires

W:ET uses .skin files to configure the information for accessoire models of the body model. It is usually located at the same place of the .mdm file we just imported. Let's take a look at models/players/temperate/allied/engineer and beside the .mdm file in this folder you will also find a .skin file called body_engineer.skin. The file encodes shading and attachment information.

The information is made up of key-value pairs. For example md3_hat defines the helmet model found at models/players/temperate/allied/helmet.md3. This helmet model is supposed to be attached to a tag object. Unlike the information for shading which describes real surface names (for example l_legs), the name for the tags are again ... magical. You have to browse the source to find out the actual name. For example md3_hat maps to tag_mouth. To make it a bit more confusing, tag_mouth is actually located in the head model, not the body model.

The addon provides a method to read these .skin files and automatically import and attach the accessoire models. Go to the Attachment Panel of the addon and switch the method to Skinfile. For the input field called Game Path enter the path to your game data. This is usually the etmain folder containing all extracted .pk3 files. We prepared this folder in chapter Extracting the game data. For the input field called Skin Filepath choose the absolute path to the skin file from above. It's relative path is: models\players\temperate\allied\engineer\body_engineer.skin.

Deselect everything, then select the body collection to make it the active collection, and click the Attach Button. Your models will then be imported and attached to the appropriate tags from the body model. We need to fix the helmet attachment, because as mentioned, the helmet references tag_mouth from the head model, not the body model. In the Attachment Panel switch the method again to Collection. Then proceed like in the previous chapter to attach the helmet collection to the tag object called tag_mouth from the head model. The same goes for the rank model. It too attaches to tag_mouth. The result should look like this:

Shading

Shading just means we tell the game how to put color on the surfaces (in Blender these are the individual objects) of the model. It basically defines surface properties which tell the game how light interacts with the surface, for example to make it transparent, or to use multiple textures and blend them together. The game uses so called shader names for that.

In this addon, the shader name of a surface is encoded into the material name of an object inside Blender. If there is no material after import, then this is totally normal. This just means the game uses .skin files to shade the model. If we look at our imported models in Blender and expand their outliner views, then we can see that only the backpack model contains materials. Note the names of the materials, these are relative paths to the game path.

The Shading Panel therefore provides two methods: shading by "Material Names" or shading by "Skinfile". Let's do the shading by material names first. In the Shading Panel, the input field called Game Path should be already set from the previous chapter. To see the shading, we must switch Viewport Shading to Look Dev mode. Then we select the backpack collection to make it active and click the Apply Shading Button in the Shading Panel.

Now for that shader name again. This is a reference to either a texture or shader script. Shader scripts are made up of small code snippets defining surface properties. Each code snippet is headed with a shader name. If the game does not find such a shader name in one of these script files, it will resort to finding a texture with that name. First it will search for .tga files, then for .jpg files. That is how the game finds its color info for the surfaces of the model.

We need to use .skin files to shade the rest of the objects. The .skin files are usually located in the same directory as the model itself. Here are their locations. Remember to use the absolute path.

• helmet: models/players/temperate/allied/helmet_engineer.skin
• head: models/players/hud/allied_engineer.skin
• body: models/players/temperate/allied/engineer/body_engineer.skin

Shading by Skinfile works the same way as with material names, that means we select the collection to make it active, fill in our input fields, and click the button. The addon will then read the .skin file information and apply the shading. After doing this for all three collections we get the additional shading information.

There are two surfaces which we or the addon did not shade: its the strap surface of the helmet, and the rank model itself. The strap surface shading is a limitation of the addon: it simply can't read shader scripts yet. We have to manually do that in Blender if we want to. The rank model is shaded dependent on the rank of the player ingame and this information is hardcoded within the source code.

Fixing the strap surface

The shader name for the strap surface is defined in the helmet_engineer.skin file. This is a good time to explain how shading works for .skin files, because as we saw above, a .skin file can also contain information about attachment. A .skin file uses key-value pairs to do the shading for a model. The key is be the object name (or surface name as the game calls them), and the value is the shader name.

The strap surface has a shader name called models/players/temperate/allied/strap. After searching all .shader files from the game we can find out that this shader is located in a file at: scripts/models_players.shader. The shader script has 2 lines: the first line tells the engine to draw the surface from both sides (culling disabled). The second line contains the reference to a texture. We will use that texture for shading.

As already mentioned, the addon does not support reading shader scripts, so we just copy the path to the texture which is: models/players/temperate/allied/inside. As it happens, this shader name already exists in our current set up, so we just assign this material in Blender to our strap surface.

Fixing the rank model

The rank model uses multiple shaders, because each time a player ranks up in xp, another shader is drawn. For that reason the shaders are hard coded inside the source code and change dynamically. Let's apply some magic again and use the shader name gfx/hud/ranks/rank4 for the material name of the strap surface. After using the Shading Panel again we see that the rank model is shaded by the texture, but the texture is meant to be transparent.

To apply our last fix we will open up the Shading Workspace. After opening the workspace, you will see the standard nodes the addon wrote. These nodes get written when you use the Shading Panel.

To make the texture transparent inside Blender we add a Transparent Shader and a Mix Shader and connect them. Additionally we open up the Settings Panel by pressing 'N' in the node editor and go to Options. There we set the Blend Mode option to Additive.

If everything went successful, we have a first basic character going in Blender, ready for screenshots, icons, and the many more possibilities of Blender. That concludes the import example. In the next chapter we will export that same character for use inside the game.

Export of the Character

In this section we are going to export the character from the previous section to an MD3 model. This model will include the bind pose frame, a walking animation, and an idle animation. But before that, let's review what we already have.

What we have

In the previous section we imported, assembled and shaded a complete character from W:ET. We have 5 models: body, head, backpack, helmet and rank.

As we used the shading panel to shade the model in Blender, we now have all shader names in Blender. These are represented as material names. We will keep on using these material names for export. The alternative is deleting them all again and use the object names inside .skin files for shading, or a mixture of both.

The body model and the head model are the only models which contain animation. The body model is animated by a skeleton. The head model is animated by shape keys. Since we export to MD3, this is totally fine. The skeletal data will just be converted.

Additionally, we should probably clean up our tags. You might have noticed that some names, for example "tag_mouth", end with ".001". Also, since we don't plan on using them anymore, we should exclude most of them, if not all, from the export by making the objects invisible. But for now we leave everything as is.

Preparing the animations

Before we export, we must prepare our animation data. We have to choose which frame ranges we want to include, and modify the existing animations so that only a couple of animations are exported.

Deleting existing animations

We do not need the animations for the head model, so we will remove them. The imported animations are stored as actions inside Blender. We can delete them in the Outliner editor type. There we switch the Display Mode to Blender File, locate the Actions tree, and delete every action except the mdx_skeleton action. We delete the actions by selecting them, right clicking the marked context, and clicking Delete.

Choosing frame ranges

Animations for models are referenced by .anim script files by the game. We can look into these files to get an overview. For the head model the script file is located at: animations/human/head/base.anim. For the body model it is located at: animations/human/base/body.aninc.

From our body animation we want the bind pose frame, an idle state and a walking state. After opening the file for the body animation we choose the following frame ranges:

Animation Name	Start Frame	End Frame	Duration
relaxed_idle_no	1094	1312	219
relaxed_walk_1h_2	1458	1553	96

Additionally, we pick frame 32 for the bind pose frame.

Editing frame ranges

We need to delete and move certain keyframes. For deleting the key frames we use markers. The markers will help us to select all key frames in between them, so that we can delete them. To set a marker go to the Marker menu in the time line and click 'Add Marker'.

We put markers on the following frames: 0, 31, 33, 1093, 1313, 1457, 1554, 4862.

Next, we need to switch our editor type from Timeline to Dope Sheet. Inside the Dope Sheet Editor we switch to Action Editor and select the Action called mdx_skeleton. Then we select all pose bones by selecting our armature object, switch to pose mode, and select them all. Finally select the markers at frame 0 and 31, go to the Select menu and click Between Selected Markers. The selected key frames can now be deleted.

After doing that for all our frame ranges, we have only 2 animations left. We need to move them to the beginning on the time line. We do this by selecting them, and pressing 'G' to drag them around. If everything went successful, you should have your key frames set up, ready for export.

For the export we use the Export Panel. First set the end frame in the time line (in our example it is 315). As we do not want to include the rank model for export, we simply hide its collection in the outliner. Finally, fill in the panels input fields, select the top level collection called Scene Collection and click the export button.

That concludes the export example. You can download the final character here if you want. In the next chapter we are going to delve into export in more detail.

Export

This chapter describes how to create and prepare a new model for export. It also gives an overview of the Blender data which will be considered by the addon.

Blender Data

During export, the addon will scan for mesh objects, armature objects and arrow objects in the active Blender collection and all its sub-collections. The following gives an overview of the Blender data it might consider.

Mesh Object

Data	Description
object transforms	Location, rotation, scale. Includes animation.
name	Used for .skin file shading.
vertices	Animated either by shape keys or an armature. Only one type of animation is supported for each mesh object. Some vertices might get duplicated to the resulting export during uv map pass.
faces	Have to be triangulated.
uv maps	Only the active uv map is exported. The format requires a 1 to 1 mapping of each vertex texture coordinates to the UV map. For this reason vertices might get added to the export data. To avoid this you need to reduce the number of seams crossing each vertex and keep your UV island count as low as possible.
materials	Only the material name will be exported. The material name will be the shader name for the surface in the export data. Nodes from the node editor will not be considered.

Armature Object

Data	Description
object transforms	Only location, rotation. Includes animation. Scale is not supported.
edit bone: name	Will get mapped to the bone name.
pose bone: object transforms	Only location, rotation. Scale is not supported.
pose bone: 'LIMIT_DISTANCE' constraint	Needs to be present. This is a format requirement.
pose bone: 'Torso Weight' custom property	Needs to be present. Can be found in the "Bone" context in the properties window under "Custom Properties".
pose bone: 'Torso Parent' custom property	Needs to be present on only 1 bone. Can be found in the "Bone" context in the properties window under "Custom Properties".

Arrow Object

Data	Description
object transforms	Location, rotation, scale. Includes animation. If parented to a pose bone, the tag must not be animated.
display type	Needs to be set to 'ARROWS'.
name	Will get mapped to the tag name. Must start with "tag_".
'Torso Weight' custom property	Needs to be present only if export to MDS.

MD3 and MDC

MD3 and MDC are both morph based formats. You can prepare your model in Blender and export to both of these formats without problems. However, you can not export to MDS or MDM/MDX, because these require a skeleton.

Basic

The steps are: create the geometry (a cube for demonstration), triangulate it, uv unwrap it, add a material to it and name the material according to the conventions.

For the material name the addon expects a path relative to the game path. This path is called a "shader name" by the game. It is either a script located in .shader file, or it is just a .tga or .jpg texture. For this example we use: "textures/props/box_m05a".

If you want to use .skin files instead of material names for shading, you there is no need for a material with a special name, because in that case, the object names become important.

Animation

Animation can be done by using absolute shape keys (relative shape keys are not supported) or object transforms. If you do not need animation, just set your frame count to 1 in the timeline, but you can also export multiple, static frames.

Before you animate with shape keys make sure you have triangulated your objects geometry, because Blender does not support triangulation after the object has been shape keyed.

Tags

Tags are represented as Empty objects in Blender. They need to have display type 'Arrows' and their name needs to start with 'tag_'. Tags can be parented to any other object.

Some models exclusively contain tags, for example first person models. Therefore the addon supports exporting tags only.

Export

To export your model, just make the collection containing your objects active and then use the export panel. The addon will read all objects contained in the collection and sub-collections. If you want to exclude certain objects, just make the object invisible in the viewport.

MDS and MDM/MDX

MDS and MDM/MDX are both skeletal based formats. You can prepare your model in Blender and export to all of the formats, even morph based ones.

Basic

The steps are: create the geometry (a cylinder for demonstration), triangulate it, uv unwrap it, add a material to it and name the material according to the conventions. Then create an armature and parent your object to the armature. Make sure that each vertex has a maximum of 3 weights. This is a format requirement.

See chapter MD3 and MDC - Basic for more details on the material name conventions or using .skin files.

For the bones: these will need a "Fixed Distance" constraint on each pose bone. Additionally all bones should have a "Torso Weight" property and on one of them there needs to be a "Torso Parent" property present. See section Blender Data for more details.

Animation

Animation is done exclusively by animating pose bones or animating the object transforms of the armature. You can not use shape keys alongside skeletal animation, nor can you animate tags themselves (they need to be animated by the bone). There might be problems with scaling the armature. See section Armature Scaling for more details.

If you do not need animation, just set your frame count to 1 in the timeline, but you can also export multiple, static frames.

Tags

Tags are represented as Empty objects in Blender. They need to have display type 'Arrows' and their name needs to start with 'tag_'. Tags can be parented to any other object, but if you export to MDS or MDM/MDX you need to have your tags parented to a pose bone. Additionally, the tag itself can not be animated, the formats require the parent bone to animate the tag.

Tags exported for MDS additionally need a "Torso Weight" property. See section Data Overview - Arrow objects for more details.

Export

To export your model, just make the collection containing your objects active and then use the export panel. The addon will read all objects contained in the collection and sub-collections. If you want to exclude certain objects, just make the object invisible in the viewport.

Convertability

If you use the "Direct Conversion" Panel or are exporting a model prepared in Blender, then the addon converts your data in a best effort. In a nutshell: you can export or convert your data into all directions except for MD3 and MDC to MDS and MDM/MDX. The reason is that MDS and MDM/MDX require a skeleton to animate their vertices and tags. MD3 and MDC do not contain skeletal data. Reconstructing this data is not easy.

The following graph gives an overview.

Panel Description

This chapter describes the panels, its input fields, and expected results.

Import

The import panel allows for import of models.

Input Fields

Input Field	Type	Description
Format	Combobox	Sets the format to import
Filepath	Textfield	Path to model file on disk
Import	Button	Starts the import operation
Bindpose Frame	Integer	Sets the bind pose of the skeleton and therefore the edit mode meshes. Context-sensitive on format input field and optional.

Results

By clicking the import button the import operation will start. The addon will then read the model data from file and write it into Blender as a collection.

Export

The export panel allows for export of models.

Input Fields

Input Field	Type	Description
Format	Combobox	Sets the format to export
Filepath	Textfield	Path to model file on disk
Export	Button	Starts the export operation
Collapse Frame	Integer	Sets the collapse pose of the skeleton. Context-sensitive. The collapse pose is used for the LOD algorithm in MDS and MDM/MDX. It should be a pose with the major joints like knees and elbows bend as far as possible.

Results

By clicking the export button the export operation will start. The addon will then read all data found in the active collection and all its child-collections. Only mesh-, armature-, and empty objects are considered. Dependent on what format you export to, the model data will be converted in an best effort. See chapter Export for more details on how to set up your blender data.

Direct Conversion

The direct conversion panel allows to directly convert between model formats without writing the data into Blender.

Input Fields

Input Field	Type	Description
Source Format	Combobox	Sets the source format to convert from
Filepath	Textfield	Path to source model file on disk
Target Format	Combobox	Sets the target format to convert to
Filepath	Textfield	Path to target model file on disk
Convert	Button	Starts the direct conversion operation

Results

By clicking the direct conversion button the direct conversion operation will start. It will read the source model and then convert and write back to the target format without writing to Blender. See chapter Convertability for more details on which formats can be converted between each other.

Attachment

The attachment panel allows to attach objects to a tag object inside Blender. It mimics the games attachtotag operation found in mapscripts.

The addon uses different methods for finding the objects for attachment:

• Objects: allows to select a set of objects for attachment. First select the objects, then select the tag object to make it active, then click the "Attach" Button.
• Collection: automatically selects all objects for attachment which are present inside the collection. First select the collection, then select the tag object to make it active, then click the "Attach" Button.
• Skin File: allows to select the models for attachment by using information from a .skin file. All models found in the .skin file will be imported. First select the collection containing the tags, then fill in the additional input fields and click the "Attach" Button.

Input Fields

Input Field	Type	Description
Method	Combobox	Sets the method for attachment
Attach	Button	Starts the attachment operation
Game Path	string	Sets the path to the game data. Context-sensitive. The game data is a folder like etmain in W:ET. It should contain all PK3 files, but extracted, as the addon will not attempt to extract them during the operation.
Skinfile Path	string	Sets the path to .skin file data. Context-sensitive. A .skin file contains information for shading or attachment. It consists of a list of key-value pairs. For attachment the key will describe a surface name. The value will describe the model path on disk.

Results

By clicking the attachment button the attachment operation will start. If successful, it will parent a set of objects to a tag object. It will therefore align the objects origin to the location and orientation of the tag object.

Shading

The shading panel allows to shade existing objects inside Blender.

The addon uses different methods for finding the textures:

• Material Names: allows to shade all objects inside a collection by using its material name as a reference to a shader name. First select the collection which should be shaded, then fill in the input field for the "Game Path", then click the "Shade" Button.
• Skin File: allows to shade all objects inside a collection by using information from a .skin file. First select the collection which should be shaded, then fill in the input field for the "Game Path" and "Skin Filepath", then click the "Shade" Button.

Input Fields

Input Field	Type	Description
Method	Combobox	Sets the method for shading
Apply Shading	Button	Starts the shading operation
Game Path	string	Sets the path to the game data. Context-sensitive. The game data is a folder like etmain in W:ET. It should contain all PK3 files, but extracted, as the addon will not attempt to extract them during the operation.
Skinfile Path	string	Sets the path to .skin file data. Context-sensitive. A .skin file contains information for shading or attachment. It consists of a list of key-value pairs. For shading the key will describe a surface name. The value will describe the shader name. This is either a shader name from a script file (not supported) or a path to a .tga or .jpg texture.

Results

By clicking the shading button the shading operation will start. If successful, the addon will find a texture and apply a basic set of nodes in the node editor. This data will not be considered during export.

Unzip PK3s

The Unzip Pk3 panel allows to unzip game data from PK3 files. Its main input fields are text fields to choose the source path of the game files and target path for the directory to copy the extracted data to.

Input Fields

Input Field	Type	Description
Source Filepath	string	Sets the file path of the folder containing the game data. This is usually the etmain folder containing all compressed .pk3 files.
Target Filepath	string	Sets the file path of the folder which will contain the extracted .pk3 files after the operation.
Unzip	Button	Starts the unzip operation

Results

By clicking the unzip button the unzip operation will start. The addon will find all pk3 files in the source directory and all its subdirectories, extract them, and copy them to the target directory. This operation is meant to prepare the game data path which may be required for other panels.