I’m trying to achieve a specific style of rock as shown in the image below; however, I don’t know how to do it. I’ve looked over several tutorials on sculpting and even then I still can’t seem to replicate the look. Also, when I try to bake a normal map of my high poly rock to a low poly rock using a cage the normal map comes out strange with plenty of seams.
tl;dr: How do I make rocks that look like these?
One thing I see is that there appear to be many “flat” planes there. A way to get that is either with the knife tool, or booleans. You would basically knife those flat edges off at various angles from whatever form you want, likely a cube. Then once you get what you want, you can apply a bevel to smooth the sharp corners and that will give you a good start to sculpt off of.
Then, to get some of the roughness, you would sculpt it into form with bumpy brushes. About the strange seams in your normal map…I’d have to see the model and baked normals to possibly have an idea why it is happening.
As of right now, my processes goes like this: add a ico sphere with around 300,000 triangles, then use the scape tool to flatten out all the edges, then I attempt to sculpt those nice bumpy details the example has. I don’t know how the creator created them, any ideas?
I’ll get a picture of my unwrap, my normal and it put all together in unity when I get a chance.
I’d have to see what you are using to go for those bumpy details…I recommend using texture brushes if you currently aren’t. You can use bumpy alpha type of brush to easily get some bumps, and you could also use some cloudy textures as well to get some variety.
I’d also wonder how you are doing the retopo, and how close it is to the sculpt.
As of right now I’m using a decimate modifier for the retopology.
I don’t know how good of results you can get using the decimate modifier. It doesn’t usually do very well from my experience, and that may be some of what is causing your problems with the normal map. Some people do it your way, starting with a heavy sculpt, and the then re-topoing in some manner to get the low-poly version. I personally prefer to start with the low-poly, and then once I get the basic form right, I use the multi-resolution modifier to get the geometry I need for a nice sculpt. Although recently, I tend to not even mess with baking a normal map in Blender, just doing it as part of the material painting process in Substance Painter, which lets me paint normals as part of the coloring and totally avoids the whole baking thing.
Thanks for the great advice on going from low poly to high poly. But as for using substances painter, afaik it’s not a free program so it’s out of my reach. Any techniques or tutorials I could follow for creating a good bake?
If it interests you, try doing to low, then high, like I mention. Then try the bake with that, even if you make some simple sculpts, just to see if you don’t get bad bakes. If you do with simple brush strokes, then post pictures, etc… and we can troubleshoot from there. Honestly, I bet changing your method will likely fix your bad bakes(could be wrong though). Once you fix the baking problem, then you can figure out how to get the nice textures you want for your baking. I highly recommend using Blender’s internal textures for this where you can. They work well in many cases. Though you can also find plenty of brushes/alphas online as well to help with your painting and scultping.
Here is a rock I’ve sculpted low poly, it’s normal map and the result. Maybe this can give you some insight on what I’m doing wrong. Im using a cage bake to render my normal map.
It might be better to just upload the blend file somewhere so I can take a direct look.
One thing I’m seeing…are you intentionally making the triangles/polys visible? If not, I’d check out the smoothing of the normals. If you select it as an object in object mode, you should find on the left a button for “make smooth” which would make it a smooth looking surface. I wouldn’t be surprised if this is part or most, if not all of your problem.
