Could you explain how you made the custom grunge generator?
Amazing work sir! Congratulations
3d hobbyist Alen Vejzovic was kind enough to talk to us a little about the way he builds 3d rocks for his amazing 3d environments.
Hello, I am originally from ex Yugoslavia, but I’ve been living and working in Sweden for the last 25 years now. 3D is my hobby, but occasionally I do some freelance work. In school I studied electronics and IT-system. 3D is something I picked along the way for a couple of projects I did in Photoshop. Now I love everything 3D. Tools I use the most are: Zbrush, Substance Painter, Octane Render, MODO and Photoshop.
I love making rocks in 3D. It is a challenge, it is hard, but it is fun. I even started on Gumroad with some of my rock packs, so if you like them you can get them there. I am also making a step by step tutorial about my rock creation technique and it should be out in a month or so.
The main challenge is to “escape” the sculpted look of the rocks. Basically, you have to destroy a nice sculpted rock you’ve been working on for 5 hours to get one step closer to that half natural look. You can’t compete with nature and it is important to know, when to call it done.
- Deciding what kind of rock I want to make.
- Spending hours gathering references (read-browsing google images).
- Making 2d shapes (contours) in my notebook (paper notebook).
- Making 16 bits alpha brushes from scans or substances of that particular rock.
- Blocking out the shapes in ZBrush and then sculpting using 3d alphas (store morph target and morph brush are of big help here).Exporting hi-res sculpt and baking the maps in xNormal for the decimated and UV-ed mesh.(now I’m also using Substance Painter for baking the maps as well).
- Importing the lower poly mesh in Substance Painter and painting textures using Substance Painter’s superb masking tools.
- Exporting the PBR maps.
It is very hard to make a rock that scales so well. Rocks that I make can be scaled like twice its size to look acceptable. If you made a mountain out of it, it would look completely wrong. For the large rock formations, you are better off using modular rocks or even terrain height maps.
I am still exploring the best approach to making the rock textures. You can’t just slap on a nice scanned texture and hope for a great result. I usually take one texture that I like and make several variations in Photoshop. Darker and lighter versions for cracks and edges. Color variations for main body of the rocks and then blending all of them in Substance Painter using masks and filters.The ambient, surrounding the rocks, is very important as well. Today we have PBR materials that adopt very well to any ambient, but you still have to make those wet and dry spots, moss, sand and snow accumulation etc.
The wrong way of using rocks is to just stuck them into ground and call it done. You should always “dress” the rocks. Foliage, dry leaves, small stones, small dried branches even trees for the cliffs etc. help bringing the sculpted rock closer to reality. I think that “tropical” rocks could work in Scotland landscape if you dress it in the right foliage. Why not. It could look a bit off, but they are just rocks after all.
For the most part, I am making rocks for the environment concept artists and amount of polys is not my main priority. I usually end up with a 20k+ polys per rock. For use in game engines I would retopologise them by hand, being the only way of preserving all of the the main features of the sculpt. It also works when decimating the rocks in ZBrush, while preserving the UVs, with OK-ish results.