Modeling and rendering a sci-fi weapon

Concept artist Chris McCabe explains his process for modeling and rendering a sci-fi weapon asset with 3D-Coat, KeyShot, and Photoshop...

Hi, my name is Chris Tulloch McCabe and I am a concept artist. I will be showing you my process when designing a sci-fi weapon. This workflow and approach would be easily applied to other assets like vehicles, structures, or armor. I will work in 3D mostly, as I like its flexibility and having the option to relight, change material treatment, and pass the model on to other members of the team. Giving them at the very least a good solid base to build on, or for a prop to have something to 3D print and prototype. Let gets started!

Step 1: Coffee, research and reference

So, when starting your weapon design, this stage is crucial. Get yourself a hot drink, put on some music and just dive in. Think about your brief; make some rough notes based on that, things like sci-fi rifle, cold planet, ice, glass, wet, black granite, elemental damage. Then I would begin internet searching or looking through books/magazines. Try and stay loose and open to ideas at this point. Think abstractly and it won't be long before headphones become fuel injectors, modern sculpture becomes shields, and car door handles become daggers.

For me I find avoiding concept art is good. It can sometimes be helpful to look and say "Right, that's the level of finish I want on my design or render style like that" but beyond that you are taking on secondhand designs. Obviously all designs are second, third, thousandth-hand, but to inject your design with something fresh looking and interesting, is important to look at something designed for a different purpose. Once I get a feel for the themes and shapes I like, I start pulling images, thinking about materials, shape language, lighting, details that may be difficult to invent on the fly, and any little nick-nack, table lamp or watch strap that just works for you.

Step 2: Sketch and clear the cobwebs

Now that you have a grasp on the brief and the vibe/language that you will use to answer it, it's time to start in earnest. Now with the next stage, I find putting pen to paper is good. This is just for you. No pressure! Don't pull out your beautiful vellum leather-bound sketchbook and your set of 36 Copic grays. Just a pen and any old paper: I am just trying to start the process of translating my reference into both logical and pleasing shapes.

With mine, I started to think about what shapes and compositions I might start with. Don't over design and/or even finish them. The aim is to not go into 3D cold. This step is becoming less and less of an issue with artist-friendly 3D software and 3D sketching is real! But anything that requires pushing and pulling of points is no-go at this point. If you have a totally open brief or you are just having fun in your own time and experimenting, jumping right into 3D and kitbashing, or exploring inside a car engine model with a point light and wide angle camera to find cool shapes or any of the other plethora of options in 3D, it's cool. Jumping in is fine but for a more specific brief like I have set myself, it's best to have a rough idea of what you plan to do in your first hour of modeling.

Step 3: 3D sketching and kitbash

Once I have a rough idea of what I want to start with, I get to modeling. I start by using a dark material on the models with a small amount of reflection to suggest internal volumes. This again helps to stay light and creative. To see the model abstractly and read into shapes loosely. Squint your eyes as you work. 3D-Coat's voxel-based sculpting is utterly awesome for this stage. For me, I like to work like I am using clay. Slicing bits off until I am happy with the shape. (Not to mention very, very therapeutic) I used a mixture of this and kitbashing my own assets built for previous concepts.

Using any of the amazing kitbash resources out there are great and if you get the time or chance to build your own, save it and re-use it, flip it, bend it and duplicate it. It's amazing how much mileage you can get out of a few good premade assets. I used mainly 3D-Coat's 'Build' and 'Primitive' to build up a rough mass and then the 'Cut off' tool. Also, for creation overlapping and more complex shapes, I used 'Vox Hide' to hide voxels! Then use 'Cut off' to remove mass left. At this point go to Geometry > Unhide All to bring the hidden Voxels back. This can make some pretty crazy, complex shapes that would make your head hurt if tried in normal, non-sculpt based poly modeling.

Step 4: Make your silhouettes work for you

Now this step really isn't a must and it depends on your time. But if you have a set of 3D sketches, use them. Not just side-on classic silhouettes; explore angles. If you have an in-game model import it and put the weapon in its hand. Try a 5-minute light setup. Pull it apart, magazines out, battery pack ejection. Any or all of these are good. But the point is, if time permits, make the sketches work for you.

If you have taken the time to learn 3D and you have to work around its pitfalls, play to its strengths and this is definitely one of them. The difference between screen grabbing some side projections and switching on a light, rotating the camera and bringing a character model in is literally minutes in 3D. Being able to stress test a design now, and avoid getting further down the line with a design that's not working, is awesome and you will be a happier person for it and who doesn't want to be happy?

Step 5: Final model building

Once you decide on a design to take forward you can start building on the details. For me, it's a less stressful phase, as all the major design decisions have been made and is just about deciding when and where details should be added. It is worth mentioning that it's very easy to just go Baroque-crazy with the details, especially in 3D. This phase has less focus on major design decisions but you still need to think about giving your eye rest, and where to place those oh-so-juicey details. It's a balancing act. A nice shape with details totally encrusting the surface never looks good.

So, tech-wise, I took my base Voxel Mesh and upped the resolution to about 9 million so I could get nice sharp edges. Sometimes I needed to rebuild the shape in places but again, 3D-Coat has got you covered. If you take a shape and just jam it into the other, so long as they are on the same layer in the 'Vox Tree' they will be merged so you can do the rebuilding of shapes very easily and then trim the excess. I also build most of the actual mesh details on the model itself as opposed to doing things like panel lines, clips and buttons with Normals at the texture phase or with paint in Photoshop. It doesn't really matter which way you do it, whatever is more comfortable for you.

Step 6: Export and render

Once you're happy with the final model you can export it. There are a few ways to go on that and the process is a tutorial in itself. There are lots of dull but helpful videos out there on how to export high poly meshes from your 3D sculpting software with normals and optimized mesh. I basically decimated the model and brought it into Octane. As I was pushed for time I rendered the whole model a number of times with the different materials I planned on using in the final painting, and just used mattes in Photoshop to choose where they should appear. If you have time, you can either export UVs or all the mesh broken up into its respective parts. Here I find it less destructive to do it the way I have. It means I can change my mind in the final paint phase in Photoshop as much as I want.

Step 7: Paint phase - Materials

Here I experimented with how the materials would be applied to the weapon and it's lots of fun. The more renders you export the more versions you can produce. I had a pretty specific set of colors and material types so I didn't go crazy, but how they are layered out is free game. I would encourage you to still experiment at this stage. After at least a day of heavy poly detail modeling you may feel that your concept is on rails, and the final outcome is already decided but there is still time to make some pretty big changes with regards to how to design is read. Also, if an art director says that they might like to take another pass at the paint job on a weapon at a later date, you still have all the ingredients.

Step 8: Paint Phase - Details

I decided that I wanted to add some small extras such as stickers, text, and scratches. For a sci-fi weapon this is a great way to sell realism. It's not real, it's silly in truth. So how do you reduce the risk of something seeming as silly as it is? Well embedding things that you would associate with actual day-to-day items is good. Screws, scratches on corners that would be exposed or rubbing on armor, or cloth. Utility stuff like warning stickers and model numbers, clips and latches in logical places also. This stuff also helps give a sense of scale and weight. Your brain will subconsciously look at these details and compare them to everyday items, and tell you how big or heavy it would be.

Step 9: Paint Phase - SFX

I decided that I needed to work a bit more on the water in the middle. I wasn't happy with the look out of Octane and more importantly didn't think the idea that this water would swirl and high speed was coming across. So yeah, some wave photos, wet mixer brush and motion blur later, and I was happier with the way it looked. And more importantly, the idea was understandable on a first read.

Step 10: Conclusion

So, there we have it; my workflow for creating weapons. As I said at the start, it can be used for other stuff too. It's flexible and helps avoid getting bogged down along the way. Staying excited and allowing for creativity at each stage is key. You don't even need to take it all the way to a high detailed model and render. Frequently, a client may not need you to do so. Taking your 3D sketches and painting over with some photos laid in to inform the viewer of material options is a valid workflow too. If you need to go back in later, then you have a set of great bases to refine or even use on other concepts such as buildings, or the canon on a mech. I hope you have found it helpful and inspiring!

Related links

Check out our interview with Chris McCabe

Chris McCabe's website

Grab a copy of Beginner's Guide to ZBrush

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