Hello my name is Marius Pieroth and I am an artist from Germany. I focus mainly on environments, but I am really interested in everything regarding 3D Art. Even though I’ve been doing this for several years now I entered the industry just a year ago. Since Sketchfab is the first platform I have provided content for on a regular basis this whole topic is very exciting for me.
When I entered the challenge I broke down my project into simple milestones: 1.) Build an alien tripod. 2.) Crash it into a building. 3.) Try to create an alien-looking alloy with different reflective properties.
It is always good to do a quick screening of your project, so you know which part will take the longest. For example: I am pretty confident in my sculpting and texturing skills, so I knew I wouldn’t have problems with that. What I had little to no experience with were destructions and simulations. For that I had to come up with something further down the line.
Sculpting and Baking with 3D Coat
3D-Coat became my main tool over the last year – not only for sculpts, but for retopos, bakes and texturing as well. You are going to see a lot of it in this article.
I established the main shapes and lines. In this case I stayed away from putting too much detail into the base mesh, because I was going to take care of that in the textures. Scratches, damages and material details would be added later. I won’t show the whole process, but I want to provide you with some tools I found useful. I started with basic spheres, moved and stretched them into place with the transform-tool. After that I used the pose-tool to deform them further. I even did the bigger extrusions with this the pose-tool. The plating is done with the build-tool combined with closed-spline enabled in the stroke options.
I prefer to tinker with shaders early on to get an idea for the materials.
I merged all objects (merge visible)to one single mesh (I keep copies of every body part for the color mask) and used 3D-Coat’s great Autopo–feature. After I created the UVs I baked the normal map and the color mask (bake ->bake w/Normal map(per pixel)).
Then I exported the geometry, the normal map and color mask as well.
Cell Fracture and Simulation with Blender
To be perfectly honest with you guys I am just getting used to Blender and I am far away from mastering it, so I will keep it short. Big shoutout to Gleb Alexandrov, who does amazing Blender tutorials. I watched Gleb’s tutorial “Blender Tutorial: 9 Ways to Destroy Things” and did a little bit of research myself.
I sculpted the building beforehand and fractured it several times. Then I placed another ceiling above everything and fractured it again to get debris on top of the walker as well. The debris objects were scaled down locally to avoid intersections and then I added rigid body to the geometry, which enabled physics simulations like gravity, mass and collision. Keep in mind that only objects that had a rigid body applied were processed. Everything else was uneffected. This option is in the physics rollout.
Next I exported the placed walker assets first, then converted the particle animation to objects, and joined everything except the walker and exported this as well. Then I went back to 3D-Coat again and imported the debris in the sculpt room as a surface object. At this point several particles had fallen to the ground or are not in view so I deleted them with the cut tool.
Then I exported the debris geometry. 3D-Coat asks if you want to reduce the polycount, which works like the decimation master in ZBrush. The end result is triangulated geometry which is kind of messy. I reduced everything as much as possing (paying attention that the edges and peaks didn’t collapse) and reimported into the retopo room. Then I utilized the mark-seams-tool and auto-map-tool. My UV-Set for triangulated geometry was now complete. While it would look messed up in some game engines, it would work fine in Sketchfab.
Then I baked again and exported the debris geometry once more.
To prevent my machine from slowing down, I started a new scene and imported the baked objects into the paint room. I had a clean scene and could continue my work.
Masks in Substance Designer
I used Substance Designer for creating my mask. For stencils there are several grunge maps native to Designer. I mainly used grunge_010 for the scratches and grunge_001 and grunge_007 for color variations in the materials. For the alloy materials I used a simple polygon shape and the tile generator note.
For the bullet holes (which are now covered in rust so they are difficult to see) I used substance as well. A blurred circle shape combined with cell_3 and the lovely slope-blur-node.
After preparing my mask I created the final materials. I used up to 7 multi-layer materials in the scene: concrete, moss, mud, rust, metallic alien alloy, plastic alien alloy. I am only going to explain how to set up one of the alien alloys. The other materials work the same way.
Texturing & Smart Materials
I prefer to use 3D-Coat for texturing single assets. For that I opened the Smart Material Editor. I switched the material type to UV, because the body of the tripod has a proper UV layout and defined the underlying material properties. When I was adjusting values for roughness I used larger steps and values which made sense, for example 10%, 25%, 50%, etc. There is not a big enough gap between 10 and 17 smoothness, so it would not be noticeable later on. For the beginners: your material is 100% metal or it is not. There is no in-between. Later on, when you are more comfortable with texturing, you can mix it up.
I rarely use more than 3 layers. The first layer defined the overall color and material properties. For the second layer I used the polygon pattern. The third layer got the same pattern with a slight color variation. I switched from overall-mode to on-top-mode. What this does is it effects only surfaces that face upwards. I used the same methods to create moss and sand, so they only appeared on-top of objects.
The last layer only effects edges and cavities and utilized the curvature map (which 3D-Coat calculates automatically).
Two side notes here: The human eye is pretty good at recognizing patterns. Every scratch that goes into a material will tile, loop and come up twice or even more and it will look artificial. To prevent this I used a second paint layer with slightly altered material instance. Second note: 3DCoat does use height maps (black and white maps) in the smart material editor. I did not use normal maps here.
A word about the triangulated geometry: as mentioned, the UV will not support UV-based-texturing. This was not an issue because I switched my material from UV to Cube mapping. Cube-mapping paints over UV seams.
Different applications do show materials in different ways. Admittedly I tinkered with the color hue in Sketchfab a bit, but not as much as you might expect. This can have many reasons. Different light properties or HDRIs or differing shader and render-setup. What I like to do is I jump into the final application as soon as possible to check my materials. After that I jump back and forth on a regular basis and exchange maps or even assets.
Composition & Fine Tuning in Sketchfab
One last word for the final presentation. Find the right camera angle and then adjust the lighting and the post effects. Your asset might not look impressive from every direction so it makes sense to present it only from one angle. This supports your composition as well.
As mentioned in the beginning I am used to working with engines and tackling larger environments which means that I have to work for weeks or even months. Besides work that is a pretty heavy commitment. Sketchfab encourages me to focus on smaller pieces that can be done in short durations. Sketchfab also enables me to experiment with different approaches and different subject matters.
Another thing is that you often can’t show your work to people outside the industry. The Sketchfab-app allows me to show it on my mobile phone any time I want which I prefer as opposed to loading a 4k wide screen rendering. When I started we surely had no 3D browser on our phones.
We are living in exciting times. 3D scanning techniques are getting better and better. Virtual reality gets more and more casual. It is a completely new field and it’s surreal to visualize your work with Sketchfab that way. I am also excited for the upcoming augmented reality solutions, which has to be on mobiles devices as well. For me Sketchfab links all those possibilities very well.
Thank you Sketchfab for the opportunity to show and share my work and write about it. And thanks to all of you for sticking around to the end! If you have any suggestions or questions feel free to write some comments for my models. I really appreciate every message and try to answer everything. Also if you like you can follow me on Artstation as well.