Sculpting monsters in ZBrush
Concept designer Fabrizio Bortolussi guides us through the creation of his ZBrush creature "Kappa"
Welcome to my ZBrush tutorial, in which I will be covering the process of how I design, sculpt, texture and render a creature bust from A to Z, using the ZBrush, Photoshop and Marmoset Toolbag 2 software. The tutorial will cover these main processes: sketching, modeling, texturing and rendering.
We will cover creature sketching, inspiration sources, base sculpting, advanced sculpting, and micro detailing. Then we'll create UVs and render the model in real-time in Marmoset Toolbag 2, before adding the final touches with Photoshop.
Step 01: Sources of inspiration
The first thing I do before starting to design a creature is get inspired, whether by something I did in the past or by any type of interesting image I come across while searching for inspiration. In this case I decide to use a resin bust I sculpted and painted as the source of reference, but keep in mind that later on I could drastically change the design or incorporate some more sources of inspiration. This is one of the most important steps in creature creation.
Step 02: Sketching from a sphere
I start to play with a PolySphere and add just a few levels of subdivision in order to pull and push the geometry. In this phase I am not concerned at all with details, just with trying to create a very basic shape that's similar to the reference image. This should be a very relaxing phase. The more excited you get with the basic sketching, the more beautiful your design will look like at the end. And it's just a matter of having fun, brainstorming and sparking your passion while moving vertices and big chunks of low-res polygons. Two PolySpheres popped inside the geometry as the eyes concludes this step.
Step 03: Finishing the base mesh
Now that we're happy with our messy blocked-out shape, we'll use ZRemesher on it in order to get a clean topology. In this way I can move the proportions without being concerned about pulling and pushing geometry too much.
We are still very low res so, even though we ZRemeshed our model, we are not yet ready to pull and push the proportions too much, but we can finalize our base mesh, trying to stick with our reference image, moving vertices around and trying to end up with something we like.
Step 04: Adding subdivision levels
Now that we have some more resolution and geometry to work with, let's start building up some basic facial features with the Clay brush. This process is crucial for the next steps since we will then sculpt finer and finer forms around the basic facial anatomy that I am sculpting at this level of subdivision, which is still pretty low res but enough for a nice facial foundation. Before adding a new level of subdivision, I observe the model from every possible angle changing the light position to see how it looks like from different directions.
Step 05: More subdivision levels
After adding a new level of subdivision I instantly see the basic forms smoothed out. The resolution is still low but I can start to flesh out smaller shapes, using both the clay brush and the standard brush. I don't want to stress the geometry too much right now, so I keep smoothing and refining the forms I have sculpted on the previous level of subdivision, adding some new smaller forms to our facial anatomy.
Moving the lights around, I can clearly see this guy is starting to get some personality. Of course, I sculpt with symmetry on for now to save time. This is not clay so since we have the chance to use symmetry...why make our life harder? I might decide to make his face asymmetrical when finished or to just leave it symmetrical. Let's see what happens.
Step 06: Refining the face
I add a new level of subdivision and now we start to get a denser and more smooth geometry. At this phase it's still too early to think about adding details, so I will focus on refining even more the features I sculpted before and I'll evaluate the surface in order to decide if I should change some features or leave them like they are. It's always hard to decide when you start to see your model come to life, but since I can't sit forever in front of ZBrush. I decide to slightly change a few facial features using the move brush and the smooth brush.
Step 07: First detail pass
Now I hit subdivide again and I finally start to see a pretty dense mesh. The geometry right now is very smooth and I can start to finalize the facial features and sculpt the first pass of details. At this point, since this is not the final level of subdivision, I won't use alpha maps to sculpt pores and micro details, but I start to add smaller shapes to my creature.
As I sculpt and move the light around, shooting a few quick renders, I can see that the creature is starting to look more and more realistic. Sculpting lip details, nose details, eye socket wrinkles and so on makes this process even more exciting, because right now I know exactly the direction I want to take. I decide to change his facial anatomy, getting inspiration from Marcus of Underworld: Evolution - in my opinion the best vampire design that's ever been made. So I mix the features of my source reference image with some new inspiration, and I end up with something I really like.
Step 08: Refining the forms
Now that I'm on the final level of subdivision I will just focus on refining each shape I see, and make sure the entire model looks sharp and ready for micro detailing. With the Smooth brush at 25% intensity, I slowly start to smooth everything out, paying attention not to erase or wash out some of the smaller forms.
This is a very important phase before adding micro details. The reason? If you have very smooth and flowing anatomy, your micro details will look natural and realistic. Make sure you spend some good amount of time on this phase and don't rush immediately onto micro detailing. I know that micro detailing is a fun and exciting process but make sure your anatomy looks neat and sharp first. Otherwise your micro details will look weird and not very natural.
Step 09: Adding the first pass of micro details
So here we are. The model is almost complete. Almost? Yes, because I still need to put some love on it. And this love is called 'micro detailing'. I gather a bunch of alphas around the net and create a few myself using Photoshop (they don't need to be high resolution for this detailing purpose) and slowly start to add pores, veins, wrinkles, and so on, to the creature's face and neck. Be careful, though - an overdose of tiny details will make your model look really bad since its facial anatomy will be covered with too many details and this won't look good at all on the final render. Not to mention that it's gonna be impossible to texture.
The key here is: patience and a keen eye on nature. If you are not sure on how to properly add a detail, look at reference images and study how wrinkles and pores are laid out on human skin. This may be a monster, but I use the same method I'd use if I was sculpting a human face.
Step 10: Preparing for texture painting
This is the last step of the modeling stage. At this point the model is almost complete, so I will focus on finishing the micro detail pass, spraying and dragging different types of alpha maps onto the creature's face without covering the first detail pass. I want texturing to be fun and exciting and not stressful. If I'd cover up details with other details I would end up having a weird-looking creature, and so texturing it would be an almost impossible task.
Micro detailing is important, but remember not to cover your model entirely with super high-resolution sharp details, otherwise you won't be able to texture it properly since usually texturing tends to cover up a good percentage of the detail you sculpted. I move the light around, shoot another few renders and evaluate the surface and what I've done so far.
I start sticking to a reference image and then changed my mind using more reference images to give my creature a more unique and pretty look. If we can call him 'pretty'! This being said, I am more than happy with my model, so let's jump to step 11 and get ready for texturing, UV making and rendering.
Step 11: Color coating
The first thing I usually do before starting a very detailed texture is to evaluate the sculpted details and decide on a color palette. In this case, since the mesh is quite detailed, our texture will make our sculpted details scream and look cinematic. Once I have chosen the color palette I start spreading some basic colors around the mesh using the Standard brush. At this stage I already know what he's going to look like at the end, but I spend quite some time experimenting with the basic colors I choose. This is one of the most important steps in texture painting. If you start to paint details already you'll most likely end up with a complete disaster.
Step 12: Basic texturing
Now that we have our basic coating done we can proceed with adding softer hues and start to play with colors, making sure we keep using our color palette choice. Too many different colors would look weird and give the character a very unrealistic look. This process can take quite some time even though it's very simple. Evaluate your base colors and choose colors that suit them. Of course, happy accidents could happen, so don't forbid yourself to 'dare' using just a few other colors. But make sure you don't end up with your texture looking like the Arlecchino of Venezia.
Step 13: Stop to evaluate
At this stage we are still very simple with our colors and hues, but I do have an idea of what he will look like at the end, so I spend some time just observing each angle of my sculpt and brainstorming on how I will approach the next phase of texture painting. He needs some more color before we can move on to a more advanced stage.
Step 14: Adding more color detail
I will now proceed to add some more color variations, slightly breaking the basic color scheme I had before. I won't be going crazy right now because it's still too early to start adding intricate details, though I'm going to add more hues and start to paint the cavities with darker colors. The key is to make sure your sculpted details won't be covered with color since you want them to be visible on your final image. So paint carefully and make sure you're not obscuring important sculpted details.
Step 15: Advanced texturing
Now I have a decent-looking base texture with some nice color variations. As you can see, I didn't use many colors, just the ones I decided at the beginning, from blue/purple to yellow/brown. I start to refine them and to add more contrast and detail to the creature. I boost up the light colors and darken the darker colors in order to have a more cinematic and realistic-looking texture. I also add a few details here and there, preparing myself for the final and super-detailed pass.
Step 16: Finishing texture painting
Right now our creature looks good but it's time to start adding some real love to him.
So, always using the Standard brush, I start to refine each cavity of my sculpt. I paint more hues and blend more colors together (always working with the same general color palette) and detail up the skin with some alpha maps and some intricate patterns.
Keep in mind that, even while painting very detailed textures, you don't have to fill your sculpt with crazy details because you'd end up ruining your paint job. Texture must be very detailed but also rational.
This means your sculpted data must be visible underneath otherwise, when shading and lighting your design, it'll just look strange and fakish. This process is the longest one since I can go on painting for hours. And it's the most enjoyable one. At least for me!
Step 17: Finishing texture painting
The texturing is finished but I don't start creating UVs yet. I always make sure everything looks right before taking the sculpt to an external renderer (in this case, Marmoset Toolbag 2). I start to orbit around the finished and textured sculpt and check if everything looks fine and sharp.
It's common to find some areas that might be not as detailed as others, and in this case you can just keep texturing. But for a client presentation I am pretty happy with what I have, so I don't feel like I need to add anything else because if I'd add too many different patterns, I could end up with a result I don't like.
Step 18: Creating UVs with ZBrush
Now that my sculpt is ready I'll create some UVs using ZBrush's amazing plugin UV Master. The steps are very simple. I open UV Master and click on 'Work on clone'. This will create a low-res clone of my high-res model. I then activate 'Enable control painting'. In this way I'm able to protect the front part of my creature. I will use symmetry and paint the area I want to protect by activating 'Protect'. You will see the color's gonna be red.
I will then paint the back of my sculpt, activating 'Attract', and the color will be blue. Make sure you leave a blank space between the two colors otherwise the UV won't generate properly.
Once finished, I generate the UV map and copy and paste it back onto my high-res finished sculpt. Now the UVs are done! Simple as lifting 130 kg on your shoulders when doing squats at the gym. (At least that's very easy for me!)
Step 19: Exporting to Marmoset Toolbag 2
Now that I have my finished sculpt with UVs, I proceed to exporting a normal map, a diffuse map, an ambient occlusion (AO) map, and the base mesh as an OBJ file. For the purpose of this tutorial I won't be exporting a displacement map since it's not needed.
I choose 6K as the maps' size so that every sculpted and painted detail will look sharp in Marmoset Toolbag 2. Before jumping into Marmoset Toolbag 2, I create a specular map in Photoshop and shrink the size of it down to 2K since it doesn't need to be ultra high resolution. I also import my base OBJ in Maya and soften up the normals, so that I'll have a smooth base OBJ and won't have any issues with Marmoset Toolbag 2 when loading the maps.
Now I'll jump into Marmoset Toolbag 2 (in my opinion the best real-time renderer out there). Steps are very easy here. I create a new skin shader and load the maps I exported into the corresponding slots. I play with specularity, glossiness and other settings making sure everything looks good. Once I have done this I simply add three lights, play with their position and give them a light bluish color in order to add a cinematic look to my sculpt.
Step 20: Finishing the image
So this is the last part of my tutorial and, to be honest, I'm a bit sad since I really enjoyed making it and wanted to do much more! Once I'm happy with the lighting I export two renders of my creature and load them up in Photoshop. Playing with the light levels, adding some contrast and painting some quick eyes finishes up my project.
I now have two cinematic looking realtime renders that are ready for client presentation. This concludes my ZBrush tutorial. I hope you had a blast reading it like I had a blast doing it. As you've seen, it's just a matter of enjoying what you're doing. If you really like your final result, then it means you did the right thing. Happy ZBrushing everyone!