Christopher Stone talked about Weapon & Hard-Surface Art, his workflow, software solution experiments, approach to the materials and more.
Christopher Stone talked about Weapon & Hard-Surface Art, his workflow, software solution experiments, approach to the materials and more.
Introduction
My name is Christopher Stone and I currently work as a 3D artist at Riot Games. Previously, I have worked on a variety of titles such as Paladins: Champion of the Realm, Call of Duty: Black Ops 3 DLC, and pre-production / early production for Call of Duty: Black Ops 4.
In my personal time, I focus on conceptual design, experimenting with new pipelines to introduce in a professional setting, and also learning more about real-world manufacturing processes.
Weapon Design & Hard-Surface Art
I’ve always been fascinated by vehicles, construction equipment, airplanes, mechs, and weapons—pretty much anything involving hard surface.
During high school, any class project that involved building something physical caught my attention and I put a lot of time into it. As I began my journey into digital art, the challenge to build something appealing while working within functional constraints was very fascinating to me. I also love FPS’ which naturally led to a personal focus on weapons and other hard-surface art.
I have also developed an interest in Industrial Design as I have spent more time working professionally as an artist. I see that same challenge of designing appealing physical products within functional constraints.
Workflow
Recently, in my personal work, I use Fusion 360 in combination with a round edge shader in Redshift to create my renders. This workflow allows me to quickly explore interesting shapes that would often take longer to traditionally model.
I typically cater my modeling techniques and pipeline to the studio’s established pipeline in a professional setting. I have used Fusion 360, Maya with Creasing to ZBrush, and 3ds Max with Quad Chamfer. I try to avoid modeling with edge loops whenever possible as I find the methods above achieve similar results faster. I will always look for ways to improve an established pipeline if the advantages and results can easily be demonstrated to other artists. When that happens, other artists are typically more excited to learn it.
In terms of the process from blockout to the finished high poly, it really depends on what I am working on. If I am creating an existing real-world weapon, I will look for as much functional reference as I can find. For example, World of Guns is a fantastic resource for finding incredibly unique weapons and insight on how they really function.
When I am working off of a concept, I attempt to preserve the overall intent of the concept as much as possible. I typically will spend time evaluating areas of the concept that will not translate well to 3D or will not properly function. From there, I will quickly block out the concept and begin to evaluate it in 3D. If changes need to be made at this stage, I will either adjust them myself or work with the concept artist to solve them. There are times when the finished model looks very different from the concept but the intent behind the design is preserved.
Take the Machtgewehr 40.4 project I worked on: after looking over the amazing concept by Piotr Kupsc, I realized there were a few areas that needed to be adjusted or explored before I started the blockout. The image below has few notes I started with. I also compiled reference images of all relevant guns that I felt would be a good reference for either mechanical function or the overall style, like the STG-44 and MP40.
From High to Low Poly
I construct my high poly with the low poly in mind whenever possible. With modifiers like Quad Chamfer in 3ds Max, I can quickly add support loops for the high poly and remove the modifier when I am finished. This cuts down time spent retopologizing, and usually means I can spend a couple of hours optimizing the model to meet the requested polygon budget. I also try to use floaters on production assets when they will achieve the same goal as modeled geometry to save time on both the high and low poly.
If I cannot use Quad Chamfer or need to transfer to an external package such as ZBrush, I will save the base geometry for use in the low poly later. A piece of advice I give students on this process is to avoid re-building the low poly from scratch whenever possible. For hard-surface assets, it is usually unnecessary unless you need to hit a very low polygon budget.
Varying Looks & Approaches
Prior to making the AUAF Peacekeeping Rifle, I had always done very clean plastic textures on weapons. So for this project, I wanted to experiment with how to make worn plastic look interesting without making it ugly in Marmoset Toolbag. At the time (2015), I was just getting into Substance Painter and was trying to learn techniques to improve my texturing as a whole.
With the Amill Industrial SMG (2018), the focus was on creating my own design rather than creating a game-ready asset. I rendered the high poly Fusion 360 model inside of Redshift using the round edge shader and created procedural materials for the texturing.
Materials
I always try to start with a factory fresh material and add layers of wear on top when approaching material creation in Painter. It’s important to think about what object, material, or operating conditions caused it when approaching any sort of wear. For example, when approaching textures on the Machtgewehr 40.4, I thought about how the gun would wear on a day to day basis, what would happen to each material if the gun was dropped or bumped into something, and how each material would change as oils from the hand interacted with it.
As I create my textures, I typically put each type of wear into its own layer for easier adjustment. For example, a scratch from the gun hitting metal may be much deeper than a light scratch that happened in the manufacturing process or during shipment; splitting these up allows me to fine tune the diffuse, glossiness, specular, and normal contribution for each.
Constructing materials in layers also allows for easy collaboration with other artists on a team. If an artist needs an older metal to work with, they can easily add layers of wear, remove layers, or tweak the Smart Material I have provided. The best case scenario is another artist adds to the material and creates something new that can be used by the team in the future.
I highly recommend students and professionals take the time to build their own collection of masks that match the type of material wear they are targeting instead of going straight to the procedural generators in Substance Painter. Every material will scratch, dent, and wear slightly differently from another (e.g.a plastic material is softer than a coated metal and as a result will scratch and dent differently). Using the same scratch masks for both will result in less clear material reads.
For anyone interested in starting their own library, I highly recommend starting with Surface Imperfections. The quality and variation in these masks are incredible and will help improve your texturing immediately.
Bade Material
Most of my materials, if not all, are built on top of a solid foundational base layer. I try to avoid using complete pre-made materials whenever possible in order to better understand material creation myself. The one exception to this is using Quixel’s base materials as a foundation to build upon. I find the quality and micro-detail of their normal maps are incredible and can cut down on the amount of time needed to re-create these through either photo-scan or by hand.
There are times when I am unable to find a base material that will work and will instead create the base by hand, like with the wood material used on the stock of the MGR 40.4. The material began as a photo from textures.com that was traditionally processed in Photoshop using a combination of High Pass Filters and hand tiling. The maps below were brought into Substance Designer and values were tweaked until I was happy with the final result.
Rendering
In my personal work, I have experimented with a few rendering methods in the past year. I have used Marmoset Toolbag 3, Keyshot, and, most recently, Redshift. I find Redshift great to work with because of its speed and integration with both Maya and 3ds Max. This allows me to iterate faster on the design, materials, cameras, and lighting.
While most of my materials tend to be pretty straightforward in terms of creation and shading, I have found the Thin Film material in Keyshot can be used to create colored polarized glass typically seen on weapon scopes. This adds more interesting detail in the render as opposed to using a simple transparent material.
Finally, I try to pull reference and inspiration from automotive lighting and presentation whenever possible. They tend to focus on how to accentuate contours, curves, and silhouettes. Gun magazines and brochures also have interesting presentations and advertisements that can be studied to improve the presentation.
Conclusion
Thanks for the opportunity to share my workflows and processes in this interview. I hope what I shared today will be useful for your future projects! If you would like to see more of my work visit my website here.