3D Units modeling for PDX games

This guide describes how to prepare for making 3D models in general for any of PDX games

Premise

Hello,
Welcome to all who would like to learn a way of making 3D unit models for paradox games.
First thing from which you need to start is chose your 3D modeling software currently there’s export plugin for Maya and Blender.

I highly advise using blender as a modeling software. As its better in comparison to Maya if it comes to modeling.

While Maya excels at animation and have few impressive features, Blender is far more accessible both being free to use and it is also way more user friendly if it comes to UI. It also have more features overall in comparison to Maya if you would like to develop further into 3D graphics.

First Steps

So you have chosen what software you would like to use? If so then now we can proceed into installing Ross-g PDX mesh import export plugin. You can get full repository here[github.com] or download release from here[github.com].

Installation process of the addon is fully described on the main page of the repository.

From now I will be using blender if your preference is Maya bad luck for you as I don’t have 3rd spare lung or kidney to pay for the license.

Here is a part you have to figure out on your own which most likely will be the most painful one which is how to use the software of your choice. For purpose of making 3D unit models you should learn some basics of:

• Low poly to Mid poly modeling,
  
• UV unwrapping
  
• High poly modeling for baking,
  
• Baking and *texture theory,
  
• Texturing using a PBR painter,
  
• **Rigging and skinning(Weight Painting) of your model,

*Texture theory isn’t necessary but will allow you to understand what you would want to use in the texturing and baking process
**Rigging isn't particularly necessary itself but will allow you to better understand how to properly apply Skinning to your 3D model.

Here’s a few great creators that make impressive tutorials for both beginners and standard users of Blender
Royal Skies makes short and very informative tutorials mainly about riggin skinning but also other elements of 3D modeling
Blender Guru, He’s a legend and made a full tutorial series for beginners that includes almost everything you should know about blender

Blender Configuration and addons

Blender is powerful and really great tool but some of its modes are only a base which you should build on with some addons:
Here’s list of free addons that will be very helpful or even necessary for texturing and baking part of workflow:

1. Ez Baker with *handplane engine, for baking,
   
2. Principled Material Layers, for PBR texturing
   
3. Principled Baker addon, For baking the final textures into desired formats

*Handplane have integration module for EZ Baker and its way faster than Cycles when it comes to baking
If you plan use external PBR painter you can skip above addons but if you want to go with blender as a one go with everything this are essential.

I also advise to use one of this two addons for Weight Painting:

1. Weight Flow
   
2. Weight Control

I have both of this since each have small and unique features that other lacks but each separately should be enough

For modeling you have to turn on in build features of blender that are turned off by default these are found also in the addon scetion and are:

1. LoopTools
   
2. Edit mesh tools

Few other addons that may be useful during modeling:

1. JCurve
   
2. JMesh
   
3. Mira tools
   
4. Forgotten tools

And least but not last addons that will greatly speed up your workflow this 3 addons require some understanding of the blender hotkey configuration

1. Pie Menu Plus
   
2. Advanced UI Menus
   
3. Quick Set

All this addons should work for Blender 3.4 and as far as im aware 3.5 which is latest when im writing this guide

Also in blender properties save&load options disable load ui option and setup your preferred file interface and options edit UI to your liking and then go to file → defaults → save startup file while this is optional it will make your experience with blender way more predictable as you wont be thrown into weird GUI whenever you change a file.

How to setup and good practices

After getting everything ready you should setup file that you plan to use by default for making units to any of PDX games. Note that this games differ in some properties between each other in some extend.

Get a model you plan to use as a base for each game some of the games have an example of a base model somewhere in the units folder. All models will be under something similar to this
path: game\gfx\models\units

It will be also a good idea to import an animation or two to make sure that everything is going safe and sound during skinning process. This can be done in the same file you're working on but if you don’t understand blender that well it will be better to make an incremental save(save as → and add a sufix _Skining) this way you wont mix up anything.

Saving incrementally is good idea for each and every workflow step, it is good idea to save high poly models and baking procedures in a branched file that wont be used in the texturing process.
Generally I mostly follow this pattern for naming files for modeling Model_name → (Model_name_baking; Model_name_texuring → Model_name_finalizing )

One that is advised for beginners:

Model_name → Model_name_skining → (Model_name_baking; Model_name_texuring →Model_name_final_textures→ Model_name_finalizing )

I’m counting that this is clear brackets indicates group and “;” indicates division between branches. If there will be some confusion ill make a graphical version and post it as a picture.

For animation I follow this pattern of naming files in the workflow:

Animation_name_FK → Animation_name_IK → Animation_name_anim →Animation_name_baked

Also it is good to check the structure in which units are used in CK3 its Low quality, Medium Quality and High Quality but for EU4 unit models change depending on the age or their type not their quality. Making a template will speed up the workflow.

General Rules

Basics:

1. Use PDX armatures if you don’t want to create a pack of animations on your own.
   
2. Note that Blender and Maya have different axial systems and while Ross-g plugin accounts for that older software like Jorodox tools doesn't. This will impact animations and models having different direction of bones and horrible epileptic attack on your screen, so don’t use Jorodox tools in other way than to preview model properties.
   
3. Note that average polycount(tris) of your final model shouldn’t be to much in comparison to base and other pdx made models. safe lane for that will be twice as much as in the base and around a quarter more as in the average of other models made for the game(this may exclude itself in case of some of PDX games as some games have base in similar polycount to average for units).
   
4. Some PDX games will use hard edges(Newer one’s) and locators(mainly HOI4) but this is game specific so I wont be diving into this problem

Important
UV:

1. Learn how to properly divide model with seams. Note that uv islands are also used within the export process. Your model will shatter if you’re going to mindlessly use auto unwrap, so divide model in a logical manner
   
2. if you plan to use Different shaders for different parts of the models note that its better to divide this part of the model out with a seam so it wont cause an issues(as far as im aware this might have been improved in later pdx games but EU4 models are really breaking without doing it that way)

General Texture Format

• Diffuse texture:
  
  • standard colors RGB channels
    
  • alpha(in most cases, some shaders are alphaless)
• Normal map:
  
  • PDX normal Red channel: Standard normal Red
    
  • PDX normal Green channel: Standard normal Red
    
  • PDX normal Blue channel: pure black
    
  • PDX normal Alpha channel: Standard normal Green
• Specular map
  
  • Specular map Red: Used as primary color
    
  • Specular map Green: Used as either 2ndary color or special amplifier for Metalic channel depending on game
    
  • Specular map Blue: Metalic
    
  • Specular map Alpha: Rougness