Creating a Xenomorph: ZBrush Workflow and Post-Processing in Photoshop

Introduction

Hi, my name is Sergey, I'm a 3D artist. Stylized fantasy-props, characters, and creatures are my favorite subject.

I often watch 3D graphics related streams and timelapse videos, usually at lunchtime or in the car while driving to work. One day I stumbled across a stream during which Nicholay Tsys created a creature from scratch to the final stage in ZBrush and that immediately hooked me. I liked how Nikolay talked about the creature in terms of form, how passionately he discussed its inner lines, and how important it is to build your micro-rhythms within a large form with medium and small details. Back then, I already knew that after a while I would start to design creatures.

Xena.75: Start of the Project

Russian CGI school “XYZ School” launched a course called STYL that teaches stylized character art for games. When I saw that Nikolay Tsys was going to be one of the teachers there, I didn't hesitate to sign up. 

Within that big course, Nikolay gave a creature design master class, but this time there was much more information because it wasn't just sculpting in ZBrush but also rendering and final compositing in Photoshop.

I watched all the lectures and after maybe a month, I just sat down at my computer, put all my business aside, turned my head off, and started creating. I didn't try to repeat the masterclass, I just did everything intuitively. It wasn't until the final stage that I reopened the instructional videos to master the techniques of working with details, skin texture, and render.

Reference

I search for references on ArtStation and Pinterest and then form a board of images in PureRef – nothing unusual here.

Xenomorph has no eyes, so I decided to pay the most attention to the jaw area, to give it a good shape. 

For the references, I gathered a few great examples of Xenomorphs made for the movie Alien: Covenant by the artists Damien Guimoneau and Colin Shulver. 

All the other references I gathered helped me to figure out how to build the jaw, teeth, and details around them. I looked at works of artists like Luke Starkie, Nikolay Tsys, and Kevin Cassidy.

Sculpting

I can divide all work on this project into three stages:

Stage 1: Designing the creature, its shape and masses within the form (ZBrush).

Stage 2: Texturing different skin areas, the smallest details of the organics (ZBrush).

Stage 3: Rendering in KeyShot and assembling all the elements into the final result in Photoshop.

During the sculpting process, I used only basic tools and ZBrush brushes. I often use the MatCap_TrueMakaR_base sculpting material from the tutorial by Sergey (TrueMakaR) Makarich.

For me, the most important and challenging part of creating a character or creature is finding the form and filling it with elements – big, medium, and small. I'm constantly watching streams, timelapses, and finished works by cool artists, and pay attention to how the masters work on the silhouette of the characters, on the external and internal movements of the forms. I think that observation, as a skill, plays an important role. 

So, the shape of the creature, the inner lines, and the support of large, medium, and small masses within the form are my main focus, and the rest is a matter of techniques. I don't consider myself a design connoisseur, I've just been learning the subject gradually, step by step, for a long time. 

For the other stages (skin texturing, small details of organics, rendering, and compositing), I mostly used techniques and tricks from the creature design master class by Nikolay Tsys.

Jaw

Since the jaw with teeth were supposed to take most of the attention, I spent a fair amount of time shaping that part of the sculpt. 

I started with one tooth on the upper jaw and placed it to the left of where the central incisors are supposed to be. Using the Mirror and Weld tool in ZBrush, I made a copy of that tooth on the other side, thus getting the first pair of teeth.

Next, I cloned these teeth in pairs and manually placed them on the upper jaw. When you clone a pair of teeth, they get their own polygroup, which makes it easy to isolate the right teeth and adjust their position in relation to the rest of the elements. 

When the upper row of teeth was formed, I cloned it and also paired everything on the lower jaw. I keep the central incisors on separate subtools, as they are very close and can stick together when using the Dynamesh tool.

When the entire jaw was set, I began to edit all the teeth individually, on and off symmetry. Some teeth were pulled and turned into fangs, others had the tops cut off to look like chewing teeth. 

During the whole process, I tried to give the teeth their own pattern and silhouette. 

Skin and Final Detailing

I used only the standard ZBrush brushes and alphas. The final stage is pure experimentation with brushes, Z intensity, brush sizes, and variation of Stroke and Alpha parameters.

The best places for detailing are at the junctions of different parts of the creature – I work on such areas with the Standard brush, then switch to DamStandard and cut the resulting bumps into small sections, then use the Inflate brush and blow out some sections with varying intensity.

To add texture to the skin, I used the Standard and ClayBuildup brushes, changing the Stroke parameters (Dots, DragRect and Spray) at low intensity and varying different standard alphas (round, stripes, grid alphas). I also used different brush sizes during the process and smoothed out the results in some places.  

I often disable symmetry at this stage of work, especially if I am working on the central part of the model because it adds vividness. It's important not to be afraid to go overboard with small details, Bumps, cracks, swollen veins, and cavities – most of these will be "lost" at the stage of painting and rendering.

Painting

I painted the creature with polypaint in ZBrush. I mainly used the Standard brush, constantly changing the intensity, size, focal length, and colors themselves. 

In the Stroke parameters, I mostly used the Color Spray option and in the Alpha parameters, I often switched to Alpha number 23 (the icon is similar to Spray). This results in an interesting color palette on the creature and gives the character liveliness. 

I also intuitively experimented with other standard Alpha and Stroke parameters – Dots, Drag Rect, and Spray, to dilute or emphasize the color palette in some places.

Rendering

Using ZBrush's External Renderer, I exported the model to KeyShot.

To set the light, I made a dark background and added 3 types of light sources:

1. Filling light in front of the model in the form of a rectangle
2. The light from above in the form of a sphere
3. Spheres with counter light to make a nice glare along the edges of the creature. Depending on my goals, I added and removed control light sources. On average, there were about 3-5 of them in the scene.

Next, I rendered the model with an alpha channel at 2000x2000 px. 

After that, I prepared some passes for the compositing stage to create the wet skin effect and shadows from ambient occlusion. For these passes, I made quick renders (5-10 minutes each); a lot of detail will not be needed here because these images will be mostly superimposed in Photoshop through the blending modes, for example, Multiply or Screen.

To create good shadows on the creature in the next stage, I applied the Occlusion texture to the model – this is the standard texture in KeyShot.

For the wet skin effect, I chose a glossy material like plastic and applied it to the model. Here I had to play with the lighting to get nice reflections. I ended up with 4 images with different highlights. I loaded all of them into Photoshop and manually erased unnecessary gloss.

Post-Process

First, I opened the basic render image of the Xenomorph in Photoshop to work on the skin.

For tinting, I simply copied the original layer, then used the CTRL+U key combination (Hue/Saturation adjustment layer) to experiment with color, saturation, and brightness. 

If I liked some of the results – for example, a more saturated blue color in a certain area created a good accent – I applied a mask to the layer and removed everything unnecessary with a soft brush. 

Then I copied the original image again and painted in different colors, applying different adjustment layers like Levels, Curves, Brightness/Contrast, Color Balance to them. Through the mask, I removed the excess.

Next, I loaded the image of the Xenomorph with the glossy material and selected the Screen layer overlay. Then using a mask, I edited or removed some of the highlights and thus got the effect of wet skin. 

For Ambient Occlusion, I loaded the image with the Occlusion texture and used a Multiply layer overlay. 

Like with all the previous steps, I just experimented with the techniques I learned in the master class. At the very end, I kept going back and forth between KeyShot and Photoshop. In KeyShot, I threw in different materials, quickly rendered the image, and added it to Photoshop. And in Photoshop, I tried different blending techniques to reach successful results.

Small veins and saliva were drawn in Photoshop with a round soft brush.

Afterword

Thank you to 80lv for the opportunity to share my experience and the result of my work!

I hope you liked the design of this creature! You can always find me on social media, I will be glad to meet new people:

• ArtStation
• Instagram

Sergey Obukhovsky, 3D Artist

Interview conducted by Arti Sergeev