Designing a Revolver Prop in Fusion 360, ZBrush & Substance

Introduction

My name is Oleg Senakh and I’m a freelance self-taught 3D artist from Russia. Most of my experiences are stock marketplace and game-ready modeling, so I can’t specify any interesting or eye-catching project that I contributed to. The main reason I didn’t try to find a full-time job is being too young for it. Only half a year ago I turned 18 and was able to register for tax paying for my freelance projects. Working freelance for me at least means that most of the projects are either private or absolutely generic, so the only possibilities to show skills are portfolio projects. And this is one of them – the first firearm I’ve created and an interesting test for a new hard surface pipeline.

Working on the EAA .357 Witchfinder Revolver

I’ve wanted to test out Fusion 360 and ZBrush workflow for high-poly model creation. In terms of concept… I had no concept. First off, I did specify the general parameters of the gun for myself. It had to be built from a lot of metal parts since I wanted to make interesting material in Substance Painter and had some ideas for it. Also, a big firearm like a rifle or machine gun would be too complex and heavy to complete as a 3–4-days project. So it was certain that some kind of revolver would be the best choice for me.

I’ve found some revolver images on Google and stumbled upon EAA Windicator. It was a solid piece for my needs and also had a ton of references available since it’s quite a cheap pistol and some folks posted reviews on YouTube talking about it. I liked its shape, proportions, and detail distribution, but decided to make the barrel a bit bigger. Only 2- and 4-inch barrel models are present, but I’ve created a 6-inch model. But changing the concept required a change of the name. I absolutely enjoy working on my models while listening to music, and while modeling this gun I’ve found myself listening to a metal band called Witchfinder General. And I thought, hey, that’s a nice name for a revolver like this! Also, it somewhat resembled the original name in its sound. Most of the references were gathered from online auctions and YouTube videos. The final reference layout in PureRef looked like this: 

The pipeline that I chose is kind of lazy, this is how it works: I modeled the gun only with the details that affect its silhouette in Fusion 360. I left surface details like text embossing, diamond notches on the handle, and a ribbon-like detail at the top for later. Fusion allows to quickly assemble the model as if it was a real object to test its functionality, so it came in handy when modeling the cylinder hinge. The handle was created in Blender with SubD.

After that, I exported the model from Fusion changing it from STEP to MOI. MOI offers great nurbs-to-poly conversion, so I can derive a high-poly and a low-poly model from CAD source one. For the high poly, I go for maximum resolution and density-consistent wireframe. I use the "Triangles and quads" output mode because the way ZBrush works with N-gons is janky (or it doesn’t work at all). I use "Divide larger than" to split up big surfaces into small quads, and "Avoid smaller than" to clean up the zones with an enormous poly density a bit. 

As for low poly, we need a clean mesh with as few polygons as possible and an easy-to-use non-triangulated wireframe. We still need to retain the overall shape of the model for correct bake, so I go with these settings: quality slider cranked nearly all the way up, but density is massively reduced by the "Avoid smaller than" parameter. With these settings, I get very smooth and detailed curved surfaces, but don’t end up with overly subdivided parts on sphere-like objects and small elements.

Now the high-poly output from MOI goes to ZBrush for chamfer and smoothing work. Thankfully, separating objects into components in Fusion 360 allows me to separate different parts into multiple subtools. Also, I’ve imported the handle model from Blender. With Polish, Polish Crisp Edges, and Polish by Feature, a clean and rounded model was achieved. Sometimes I had to mask some edges to apply different settings to them than to the rest of the subtool. Before working with each subtool, I did apply DynaMesh with around 1700-2300 resolution. 

The low-poly model received a little cleanup after export and UV unwrap. UV was semi-automatic since I’ve used sharp edges marked by MOI on export as seams. I packed the UVs with the Packmaster addon and headed out to Marmoset Toolbag for texture maps baking. 

Surprisingly, bake caused absolutely no problems, thanks to the perfect MOI low-poly export.

So now off to the creation of the materials! 

Texturing

For adding AO to new surface details the HBAO filter was used. I exported normal and generated AO maps from this project, combined the baked and generated AO maps in Photoshop, and imported them back to the new Substance project. With the new normal map, the World Normal and Curvature were re-baked, so that the new details would affect generated details in the textures.

Texturing the metal parts was a lot of fun. A cheesy trick that I’ve used was adding a curvature-mapped gradient to the edges of the model. Stacking a curvature generator and gradient map filter in the Base Color channel gave me the effect of fading color gradient from the metal surface plating of the gun. The gradient goes pink to yellow to blue from the highest curvature respectively. It might be not that realistic and more of an exaggeration of a natural counterpart but still adds much to the general look without looking wrong.

While working with metal, I added more surface details like rifling on the barrel insides and chipping on some of the text stamps. It’s important to keep in mind that you need to create big (overall grunge maps and gradient), medium (cavity dirt and edge wear), and micro (chips, subtle scratching, surface finish, dust, and so on) details, since a gun is supposed to be held in the hands of a game character. Even the most minor details can contribute to the look because of the space the firearm takes on the screen. And don’t forget to break up the generated look of the details with manual and logical masking of unneeded features. 

Grip material is much simpler, consisting of just 9–10 layers. A standard case – grainy plastic, some edgewear and fading, a little lightening on the sharp parts, grunge and dirt details on top of some scratches and caverns. 

Rendering and Lighting

Rendering each model always feels like a little side project to me. There is a lot of software for really professional and in-depth render work, but since this is not my exact specialty the best choice would be Marmoset Toolbag. In the fourth version, the Marmoset team added a path tracing-based global illumination feature, so it became the one and only way for me to create portfolio renders.

First of all, the general idea for renders was creating some studio-looking shots on a piece of cloth with the revolver on a minimalistic stand. I’ve tried a plexiglass stand, but rendering a transparent glass-like material took too much time for a quick render iteration. Switching to a metal one eliminated this problem and also looked better without excess reflections and taking too much screen space. The piece of cloth was modeled in a few minutes in Blender with the Cloth brush in sculpt mode. I did set up the render settings and quick post-effects in Marmoset for the first frame and angle. ACES tone mapping helped to lower the amount of overexposure on some metal parts and bring up the shadow areas.

The lighting setup was quite similar for all angles, consisting of a bright bar light, huge fill light, and a secondary less bright but bigger bar light for rim light effect. A lot of subtle point lights and spotlights were used to fix shadows in some places, making the scene look like a complete mess in the end. For all additional angles and close-ups, the project was duplicated and light placement was redone. 

For the backdrop, simple grey color with a vignette overlay did the job well enough. 
As an afterthought, I decided to make an outdoor-like render. I took a canister scan from Quixel Megascans and slapped some rounds onto it. Rendering with a midday HDRI gave some nice blue sky reflections and contrast shadows on a rough canister surface.

As a fine touch, I made a little revolver icon next to the name on the final renders. I just projected some details to the sketch object in Fusion and exported it as a vector image. Then imported it to Blender, added some thickness to the lines, and rendered as a transparent image.

Conclusion

I’m totally not an expert in this field, this project was my first real attempt at weapon art. But while working on it I’ve got some essential experience that I would like to share. First of all – get your scale and proportions right. Use as much reference as you can, since a gun has many moving parts that must align with each other. Another tricky thing is getting the chamfers/fillets/bevels size right. With a bevel too big or too small the scale of the gun can be ruined, making it appear wrong, especially if there is no reference to compare it like a hand of a character or another object. Also while browsing ArtStation I’ve noticed that a lot of artists use some tricks and little cheats to make the model look more interesting. A slightly unrealistic finish, metal colors, surface texture can surprisingly help make your art stand out.

I think this is everything I can share on this project. It was great to have a chance to participate in an interview like this, thanks to 80 Level and Theodore Nikitin!

Oleg Senakh, Freelance Artist

Interview conducted by Theodore Nikitin