Medieval Castle Production: Working with Modular Packs

Introduction and Career

My name is Hamid Khoshbakht. I’m a self-taught environment and level artist. I started my career as a level designer in an indie company. I worked on several indie projects and also a real-time animation series. Currently, I work in Codemasters studio as an experienced artist. The first AAA title I worked on was Grid 2019, where I mostly worked on terrain, terrain textures, and also on buildings. And now, I’m working on Dirt Rally 2.0 DLCs.

About the Idea of the Project

Well, medieval castles are always appealing for environment artists. It started when my friend Emran Bayati showed me photos of a gorgeous Spanish castle, and we decided to create such an environment in UE4 together. Although we weren’t faithful to this particular Spanish castle and tried to achieve a generic modular fortress.

The goal I wanted to achieve was a package that:

• Is simple and minimalistic
• Can be used to populate the level fast and easily
• is good looking

I wanted this set to be simple and minimalistic but highly customizable, and also to make it possible easily integrate on different levels. The reason behind this ‘’simplicity’’ was that creating a complex and full-detailed environment may take months. And it’s harder when you do such a project besides working on your full-time job!

I also didn’t want this simplicity of assets to lead to a plain and low-detailed level.

Modeling

Models can be categorized into 4 different sets :

• Modular meshes: Objects that are intended to combine together to make a bigger asset. We have around 40 modular pieces in this project.
• Spline-meshes: Objects are intended to be used via the spline tool (Blueprints) in UE4. Like ropes, chains, walls, 6 spline meshes
• Props: Unique assets. Some of these assets are textures uniquely in Substance Painter (5 props) and some of them are textures with the material layering method inside Unreal (10 Props).
• Foliage: a dead tree and some grass. 

As mentioned before, asset production time & simplicity were IMPORTANT in this project. So, we tried to avoid complex assets, especially in modular parts. All assets are made by poly-modeling in 3Ds-Max, and some rare assets had a small touch in Zbrush.

Part of the job like walls, props, and bodies was done by Emran, and I created wooden structures, foliage, and cloths.

Texturing

Firstly, I want to talk about the workflow and the “big picture”: I decided to use the Material Layering method, which nowadays is a popular workflow in Unreal Engine. In this workflow, there is a material library made with tileable textures, and these materials are used as layers in different assets. For example, one tileable wood texture is used in different wooden assets.

This was beneficial for several reasons:

• REDUCING the number of textures used in the scene. This means less effort and time-saving in creating textures, and also it’s more memory efficient.
• Easy editing materials inside UE4. For example, to match colors of assets, tweak normal or roughness intensity, etc. you don’t have to go back to Substance Painter or Photoshop.
• Creating variations via material instancing. Creating different colors, roughness, etc. can enrich the level in visual aspects and can be costless. 

For the first pass of texturing in this project, my focus was on creating a simple material library. To achieve this, I needed to create material functions using tileable textures and noises. Some simple functions I could achieve inside Unreal Material Editor by using different noises as masks (like simple metal), while for other functions, I was heavily dependent on Substance Designer (stone walls, wood, tree bark etc)

I also created a pair for wall textures meant to be used with vertex painting.

An example of tileable textures created in Substance Designer is Stonewall: my goal was to create only one substance graph but to be able to get various results by just changing input mask and tweaking parameters. It was a challenge, but the result was satisfying for me.

I created a stone wall, cobblestone, brick, and floor materials with just one graph.

The second step was creating materials and material instances.

This scene is composed of less than 20 master materials. Some of them are simple (like the master material used for unique assets) and some are more advanced.

An example of material creation is the floor. I had a tile material on a 2x2 meter module, it was repetitive, after creating a vertex-paintable material, I used a clouds noise as world aligned texture and used it as a mask to change luminosity, color, and roughness of floors. Using this world-align feature means these details will be applied non-uniformly based on the location of mesh in the world. After that, vertex paint was used to add more details to the floor. 

Advantages of the use of the modular packs

A good modular package helps you to populate your world very fast and also gives you tools and options to avoid or hide repetition.

As you know, creating large scale environments and worlds is a huge and time-consuming process and may take months to accomplish. But with a good modular design, it can be achieved with a great saving of time and resources. And also it’s more memory friendly because of instancing features and reducing textures quantity.

Rendering

Lighting: since this environment is large-scale, I didn’t want to go through the time-consuming baking light process, so I chose the dynamic lighting setup. Also, I used LightPropogationVolumes(LPV) for indirect lighting. LPV is a system for dynamic global illumination in the Unreal engine.

One thing I always do at the early stages of creating levels (before starting the asset production process) is setting up a basic lighting(something close to the desired lighting that I want to achieve) and testing my textures and materials in this setup. This way, I reduce the time of re-editing textures at the final lighting stage.

I wanted this package to look good in different lighting conditions, so I set up 3 base lightings: daytime, sunset, and night.

I created a level for each of these lightings and linked them in main test map. This way I could easily switch between lighting scenarios and check how assets look.

I achieved the final render by tweaking and playing with main light source, skylight, height fog, and post-process volume.

To make the scene more dramatic, I also created a simple volumetric fog particle using tutorials on youtube. The post-processing part was also a bit of playing with color-grading, bloom, AO, and etc. The only thing to mention is the post-process material I created to sharpen the final render to give a bit of strength to the final image.

Basic Rules of Working with Modular Scenes

Design your modules and test them by block-out before jumping into the production of the model. Creating modular environments is a precise and punctual process. Your modules need to snap and tile correctly.

Do not give character to your modules either in geometry nor texture, because these elements will repeat and will look awful. By character I mean: any high contrast detail that will catch the eye while repeating.

Although this does have a drawback. This will lead to a plain and monotonous module. To overcome this you can: 

• add variants of the main module (for example, if the main module is a wall, a damaged wall can serve as a variant) or it can be a complementary detail (like any attachment on the wall).
• Use decorative objects, props, decals, vertex paint, foliage, etc... 
• Lights and shadows give weight to different parts of the image and break the monotonous look.

• Adding world-aligned and world-space details can help you to add location-based details to modules.

Hamid Khoshbakht, Environment Artist

Interview conducted by Arti Sergeev