1. Define a style
First of all, before designing anything in 3D, you have to have a clear idea of you want to achieve. Which style of mecha is it? Steampunk and kind of retro design? Very stylized video game mecha? Japanese gundam style mecha? Ultra advanced sci fi?Military or simply just realistic?
Once you have the intention, it is recommended to search 2D sketches (Japanese line art desig,n for example). Determine the shape, the global proportions, the kind of structure, the visual language. Don’t go too much to the details - you will do it in the 3D phase.
2. Find references
Before starting in 3D, you also have to find references: it could be photographic documentation of real robots, futuristic weapons, drones, or concept art from other artists, even references from the movies. I highly recommend that you search photos of Boston Dynamic robots, real military exoskeletons, or industrial real robotic arms. Take the time to analyse them and wrote on a paper what kind of details, elements you like the most. What elements you think it will be visually interesting to reinforce the functionality of your mecha or a particular aspect of it. Try to search on your photographic documentation what specific elements you want to reproduce for your design. Real documentation will be a helpful tool when you are on the step of detailing structures or creating real articulations for your mecha.
3. Let the creativity begin !
You can use any type of 3D application, but I will recommend to work on full polygonal models. Personally, I prefer to work that way as it lets me have real control over the topology and different details on each phase for the hard surface models rather than directly sculpting and doing retopology.
At first, try to model at a low poly stage and search the shapes in 3D. Don’t worry about topology or articulations at this stage but only try to think on your general design. Once you find the silhouette and global shapes are cool, you have two approaches depending on your design: If you create a Japanese manga mecha for example, you can cheat a little about the articulations. It can be floating assets articulation which can help you pose whatever you like. Nobody will see it, the “suspension of belief” will work perfectly, and make your audience believe your mecha has a complex machinery inside and is perfectly functional.
If you create a realistic mecha (a less armored mecha like Robocain on Robocop 2) with very exposed machinery, once you have the global proportions, you have to construct the internal skeleton of articulations and think more about the functionality and his accuracy. You can test poses for examples. If there is interpenetration during the posing, you can correct the design or re-cut the parts that cause issues. A really good example you can see on movies is the Hulkbuster on Avengers 2, which have movable parts depending his pose of the arms and hands. Don’t limit your creativity! This kind of issue can be the opportunity to create interesting articulated parts, which will enhanced the overall design.
4. Detail principal shapes and enhancement of topology
The most important thing at this stage is to detail a bit more, but not too much. Work your topology so that you can add further details later. Think of the way the objects are really constructed. In real-life, simple objects like mechanical pieces are really easy to model as the shape is not really eccentric. Use your photographic documentation in order to estimate which parts need separations or not. Don’t hesitate to add a layer of complexity at this stage in cutting big elements of principal shapes. Don’t go too soon to hyper detail. It is the first stage at this step.
Like a sculpt or a 2D concept art, try to think like this: Primary shapes---> secondary details ---> tertiary details
5 . Secondary shapes
Don’t hesitate to work on layers and to cut each parts of your mecha like head layer, torso layer, thigh, legs, hips, arms, hand, big armor parts etc. Try to concentrate on each part. Never mind if there are interpenetrations or something like that, you can correct this easily later. You can cut or extract polygons on any parts you estimate as useful to add another level of complexity. This way, you use your constructed topology for small parts so that you can quickly add complex details like mini extrusions. You can either subdivide the polygons again to add more details. The model begin to gain in complexity. Try also to work the design of these parts individually: if each are visually interesting (as the global proportions and shapes were validated on the first steps) , they will blend very well assembled together.
6. Tertiary shapes
If you have a library of kitbash (that you model yourself from real references), you can use it at this step. It can be additional mini articulations, pipes etc. You can also model very detailed parts that you can add on specific areas in order to give the sensation that your mecha is a really complex machinery. You don’t have to over-detail. For example areas like armor parts need really small structure details placed on strategic areas. But you have to take into consideration that you need also to leave place for the decals on the texturing step. Leave certain areas empty of details so that the structure and 3D design of overall mecha “breathe” . Once you are satisfied on the overall mecha, don’t hesitate to add a dark shader with no specularity on your model and to check the silhouette in all angles possible. Try also to think a this stage the type of camera and shot you want for your render. Depending on that you can decide to stop this step of adding tertiary details or eventually to add more.
7. Shaders, textures, decals
During the 3D modeling and designing phase, don’t hesitate to affect a shader or color (representing specific materials) on different parts of your model.This way you work on the color scheme during all the process like a 2D concept art and it allow you to have a clear idea of the design of your mecha. The overall work design gain a lot on visibility and readability. It help a lot when you are in a rush and need to add additional details on specific areas without spending too much time on detailing. Once this step is done, then comes the texturing phase and decals. It is a really important step because it add a new layer of realism on your overall design.
A real mecha is not clean. If you observe mechanical vehicle like construction truck, you can observe that specific areas are more dirty, used or rusted. Try to add the use pattern on all parts who tend to move a lot (like big articulation parts. On the exposed armor parts , it can be more dirty or rusted than the interior mechanism. Don’t hesitate to add contrast. Even of clean mecha, there is this sort of imperfection, so try to use it efficiently in order to sell the realism of your model.
There is also several techniques on texturing. You can do a overall render on your preferred 3D application and paint on it and add decals on Photoshop. But if you need to show different views of your design, it could be problematic. So you can also unwrap UV on specific areas (like the exposed big armor parts) or all the pieces which receive decals. Or you can use procedural textures on all parts of the model and use 3D decals created with 3D letters if you need to work very fast. We are on the case of 3D design so use the technique that best suit for you and for your needs.
8. Cameras and final render
It is really important to choose an interesting point of view of your mecha which help to sell the scale and the quality of the overall design. Medium and cow boy shots are really good. Don’t hesitate to propose a close cinema shot even if some others parts of the mecha is not shown. If there is areas not shown like feet or legs, try to propose additional different renders in full view. Depending of the effect you want, choose an accurate focal length on the effect you want to achieve: for example if your mecha is really tall in hight, try to sell it in the shot in exaggerating deformations due to the perspective. If the mecha is anthropomorphic and has the size of a human, try to shoot it with less deformations possible. And don’t forget to place your camera at a human point of view.
For the renders try to create passes as much as possible. In the context of designing in 3D you will gain a lot of time if a color need to be modified with a RGB pass. Try also to calculate separately specular pass, and rim, fill key light pass so that you composit them and have possibilty to adjust individually. Depending on the technique you used and explained previously, you can add decals you created on Photoshop on the surfaces of your mecha.
We'd like to thank Christophe for providing these awesome tips. Be sure to check out his website to stay updated on his work!