Designing Post-Apocalyptic Weapons in Blender & ZBrush

Introduction

My name is Joppe Stijf and I am from a small town in the Netherlands called Dronten. The town is best known for its potatoes. I have even seen a place that sells fries made from Drontense potatoes in Valencia, where I am now enjoying my life as a Prop & Environment Artist working on AAA titles with the sun on my side. 
 
My interest in Games is what really started my career. I used to spend countless hours behind consoles and my PC. The first time I realized games had to be developed was when I started playing RuneScape on private servers, where people developed custom content to add to an already existing game. It is in this period (around 2012) that I started editing photos in GIMP for people on forums. 
 
Four years later I enrolled in the Game Development course at the Deltion College in Zwolle. Although this provided me with a solid insight into Game Development and helped me be around people with the same interest, I soon found out I had the urge to specialize and dive deeper into the world of 3D art. The artworks of the older students I kept seeing in the college hallway really inspired me to push my artistic skills. A special shoutout to Sunray Muijsson, Rick Greeve, Benjamin Vos, Nikkie de Ruiter and Niek Schlosser. It was then that I learned about 3D Fast Track, a relatively small Discord group of lovely artists striving to grow and socialize. I highly recommend finding these types of groups where people are willing to provide feedback. After building my first 3D portfolio on ArtStation I got my internship at Team6 Game Studios. Here I contributed to my first professional project called Street Outlaws: The List. During my time at Team6, I learned a lot from the people surrounding me and I still remain close with some of them.
 
For my personal projects, the most important thing for me is to enjoy every bit and learn something new. I recommend making what you like, not what you think others might like, especially when working on something personal.

Working on Sammy from Metro Exodus

The post-apocalyptic style has always intrigued me. The variety in materials and worn look float my boat well. In general, it is easier to tell a story through a super worn piece than it is with a more modern slick piece. The weapons in Metro Exodus are my favorite in this style, and after seeing the awesome Sammy concept from Ilya Tolmachev, I fell in love. Here are the original concepts that inspired me:

My goal for this personal project was to get better at using the ZBrush Live Boolean workflow; a fast and pretty non-destructive way of working. Besides that, I wanted to push my texturing skills and get to work on some more interesting materials. This Sammy concept was just what I was looking for.
 
Starting this project, I set a deadline for myself. It really helped me break down the process and push myself to finish this asset. Next time I am going to take pre-planning even more seriously and get a professional-looking workspace for time tracking and watching out for the deadlines, as I really wish I could know exactly how much time I spent working on each stage of the process and how much time it took in total. With this information, I will also be able to see where I can optimize my workflow.

Gathering References

So, I had this awesome concept as the main reference I could begin with. I also found out it was a mix of the AK-12 and Tommy Gun, and this information helped me a lot while gathering my other references. For the modeling part, this felt quite straightforward, but the already made weapons by Olexander Sitak and Alex Smirnov made it even easier for me to make technical choices and gave me a better understanding of what this weapon would look like in 3D. 
 
In general, I avoid using 3D art as a reference as it is someone else’s interpretation of what they see. However, for technical execution, it can help to see how someone else solved problems that may come in the process of translating a 2S concept into 3D.
 
I gather the highest-quality images I can find on Google, random websites that I find when going into the rabbit hole of pictures, and this online museum that is full of high-resolution images. Next to still images, I also enjoy watching some videos on YouTube about people that showcase and move around weapons with similar materials as the one I am making. This helps me understand their materials even better than if I was just eyeballing images.

All of this together is being collected in a PureRef file, in which I try to categorize references by part and/or material. I also find it handy to add colors to each category. I would have collected more references if my target was photorealism, but for this more exaggerated project, I was keen to keep some creative freedom in terms of material definition. 

Modeling

For the modeling part, I used Blender and ZBrush with the Live Boolean workflow. At first, I did a quick blockout to decide shapes and solve most issues that might come from translating a 2D concept into 3D. When starting with a reference image, I recommend you always start by blocking any cylindrical shape as it is going to be the only shape that will give you information about how deep the object you are looking at is.
 
To start with the high-poly modeling, I kept the models as simple as possible inside Blender and then exported all parts and their booleans separately. This way I was able to easily adjust any model. After applying the boolean operations, I use DynaMesh at a resolution that works well for the part to make sure the topology is spread evenly and the mesh is ready to get polished. I use ZBrush’s Polish Crisp Edges function.
 
In the later stage, I did a subtle sculpting pass to some of the high-poly meshes, where I mostly focus on getting interesting and worn edges. For this, I used the Trim Dynamic and Smooth brushes. I did not get in too much detail at this stage as I wanted to challenge my painting skills and rely on the use of more advanced techniques.
 
After the sculpting, I decimate the meshes so that they are optimized for the 3D scene, where I prepare models by renaming them and assigning materials so that they make for a proper bake mesh.

For this project, I only wanted the welds in two small places, so they were done pretty much manually. I would not recommend anyone to follow my exact workflow, as next time I would do it more efficiently for sure. There are plenty of ZBrush weld resources you can buy and also, I believe this polycount thread explains a better workflow of creating welds with standard ZBrush resources. 
 
To start off with the workflow I used for this project, I began with a high-poly mesh and made sure that the areas that were going to be welded were very smooth, so they did not receive any sharp seams. Then I used the Inflate brush along that edge. After this, I created a quick weld alpha and used it to brush along this seam holding Alt for a subtracting weld effect. Then at last the edges were cleaned with the Trim Dynamic and Smooth brushes.

Retopology

Retopologizing started in Blender with the blockouts that I sent to ZBrush, comparing them to the final high-poly mesh. Any big change in shape has to be applied in the low poly to get nice bakes. No fancy tricks were used here. I just started with a cylindrical shape (in this case the muzzle brake) to decide the density of the final low-poly mesh and continue with the base shapes that I had made for the high-poly model.

I made sure the low-poly mesh was optimized without showing obvious faceting. A quick tip to make sure you do not have obvious faceting is turning on some shader that helps you see the silhouette of your model without the influence of light like the flat shader in Blender.

Unwrapping

Unwrapping often starts with selecting sharp edges and seeing which angle gives the best base to start with. It is then a matter of cleaning that selection and cutting a seam on cylindrical shapes so that they can be flattened. After getting the right seams, I make a quick unwrapping and see what isles can get less UV space and which may have been distorted. Then I go around and straighten cylindrical isles and singular edges that might be important for the normal bake. For this, I use Blender's UV Squares Addon. As I only wanted to showcase this weapon from one side, I also biased the texel density accordingly. Packing then goes automatically with Blender's Addon called UVPackmaster. Always make sure to keep enough padding for the best results.

Texturing

For texturing, I used Substance Painter. The concept already showcased a very strong post-apocalyptic feel that I tried to convey by beating up the materials with strong and contrasty wear and tear (kind of an exaggerated realism). The ArtStation Learning tutorials by Rick Greeve and Jason Ord have taught me a lot, I highly recommend checking them out.
 
To begin texturing, I set up a simple folder structure. I start with a folder for materials, in which I create folders for each material I am going to need. Then I also set up folders for Normal Details, Wear & Tear, Dust & Dirt, and for polish (anything that might be added on top of the stack like a filter or some extra variation that needs to be applied on top of everything).
 
Then I begin masking different parts based on their material, starting with a fill layer that showcases their base value (color, roughness, metallic) best, and continue layering upon the materials as the time comes polishing each material more and more. 
 
During the whole texturing process I tend to look most at my roughness channel where I make sure it has got enough breakup, contrast, and is respecting the principles of usage.

Welding

The welding was done in a very simple way making use of Substance Painters’ anchor points. I masked the part that was welded with a standard brush, gave that mask values of a more fresh-looking metal, and added an anchor point on top of that layer stack. Then afterward it was just a matter of layering on top of that mask using the anchor point as the base. For this, I added a new fill on top (with values of choice), added a black mask, added a fill into that black mask, and referred to the underlying anchor point so that the mask information is equal to the fresh metal. From this point, I bevel that mask and add another fill with the anchor points reference, this time changing its blend mode to subtract. 

Baking

The tape was baked in the high poly and so it was easy to derive information from baked channels such as Ambient Occlusion and Curvature. These two maps are very important in the process of creating a good procedural base. Always respect AO and Curvature, since they really help to ground textures. 
 
To make the eagle-shaped emblem on the wooden buttstock, I made a black and white image in Photoshop by masking the eagle face from the concept art and projected this onto the stock in Painter. I then layered it with anchor points to make it look grounded. I could have done this using fewer layers, but I ended up using 4 so that I had a nice variation in the values and had enough freedom to tweak these values afterwards.

My best career investment ever must be Marmoset Toolbag 3. It has saved me a lot of time with its easily iterative baking workflow and has provided me with great real-time 3D compositing and rendering software for awesome portfolio renders. I would love to get my hands on Marmoset 4 soon, but for this project, I felt like Marmoset Toolbag 3 has been sufficient.
 
For presenting props and weapons, I like to keep all the attention on the subject. I try to achieve this by keeping a simple and one-color background and neutral lighting that respects the silhouette. I wanted these renders to feel heavy and contrasty. The breakdown below shows a quick example of how I light and tweak the renders.

Color Adjustment

I personally prefer a high focal length for these kinds of small subject shots. Besides that, I do not touch the lens settings. The true magic happens in color grading where in this project I switch from Linear to ACES color space and adjust the curves to get the nice contrasty feel I was looking for. I also showcase the renders with some Sharpen and Vignette, which can be done in Photoshop or touched up in Photoshop after.

Advice for Beginners

For the beginning artists, I think it is important to start with the basics. I think starting with props is the best way to begin your 3D career. They are usually the smallest in scope and so you get used to finishing an asset and going through a pipeline. But doing what you like is the most important thing, that is what is going to help your discipline and get you motivated. Also breaking down assets into smaller parts helps to get satisfaction and some small boosts of inspiration throughout the process. Articles like the one found on 80 Level and Polycount also give great insights that have taught me a lot.
 
I also find it very helpful to spend a lot of time looking, it is like learning a new way to see things. Try to break down assets on your computer and in real life to learn about basic things like values, variations, proportions, etc. Scroll through ArtStation looking at good art, it may very well teach you a lot, too.
 
Thank you for reading this article, I hope you enjoyed it!

Joppe Stijf, 3D Prop & Environment Artist

Interview conducted by Arti Sergeev