Where I show you how I made my second octopus, 5,5 years after the first.

Before I specialized in animals and their anatomy, my work mainly focused on technical stuff. I still do that, but my heart lies with the stuff you see overwhelmingly on my website.

This post is no different. It harks back to when my specialization began. In the fall of 2011 I was asked to make some cutaways for KIJK, a Dutch popular science magazine. I embraced the opportunity with both hands and made an adventure out of it. So I dissected a real octopus to be able to make a believable cutaway that wasn’t copy from stuff I found on the internet or diagrams in biology books.

The final octopus got great reviews, but even I could see that I still needed to learn a lot regarding the tools I used. The model was very large and almost unworkable in the end. But it showed what I wanted to show: the intrinsic beauty of the animal and its internal organs.

And I loved doing it. In the following years I learned a lot just by doing it, watching how other people did it and the fact that Sketchfab came along, forcing me to be able to optimize models while still maintaining all the details.

My work process stayed the same and I got to know the applications I use through and through. I know which one of my applications works the best for a certain part of the making process and if I am still uncertain I use a project to learn.

So now I am able to make almost anything I set my mind to. And I thought it was time to make an octopus again.

Basics

The image I wanted to convey was an octopus in a glass. The glass I made earlier for a cover that was send to Nature accompanying a paper about neurons that regulate our thirst for water. The glass didn’t make it in the cover, but I liked the look and feel of it, so I wanted to use it again. The fact that I wanted to make an octopus was because I saw “finding Dory” the other day and was in awe with Hank, the octopus.

©2016 Disney•Pixar. All Rights Reserved.

Hank of course is a very stylized version of an octopus, while I am more one for the details of the real animal. One of the artists I follow closely because I admire hire craftmanship is Keng Lye. He was one of the first that painted an octopus in clear resin and he made several versions of it. I do some clear resin work myself, but that wasn’t what I was planning for this one. I wanted to make an illustration. And that illustration should be a combination between a realistic rendition of an octopus and a work of art. Like the objects Keng Lye made, but different of course.

So I started to work in Zbrush to make the base of the model. I imported the glass I already had and used zspheres to model the basic shape of the octopus.

Zspheres are very easy to make a basic shape with, but one is easily lost in the process thereafter. So I focused on keeping the base I started out with as a base for the total process.

As you can see there is a big difference between the resolution of the topology of the arms and the body itself. So before anything else I added additional edge loops to make both arms and body roughly the same.

After that I uv unwrapped it and made a promise to myself that I wouldn’t deviate from that uv map.. it’s very tempting just to use a dynamesh for the details and get carried away, but then I would loose the complete realistic model of the octopus: the arms were very close to the body for example and they would be glued to the body after that instead of being real arms. So I kept the basic shape and worked from there.

As you can see by the different colored areas on the model, the zspheres I started out with translates into separate polygroups. Since I didn’t need a perfect uv map, I used those polygroups to unwrap the model. It also gave me room to work in, since you can easily hide an unhide polygroups in Zbrush.

I didn’t need much else from ZBrush, other than some maps. So I painted a rough texture map and a displacement map that I could use as a start for my work on the materials in Blender.

If you look closely to both maps you see that I didn’t cover every single space with details. That is because I already knew how I wanted to position the octopus in the final rendition.

After this I had the problem of the suckers. There are several semi-automated ways to make repeated objects in ZBrush and maybe I should have used one of them, but I took another path. If I ever go back to this octopus model that is probably one of the things I will do different. So what did I use? I masked dots on the arms of the octopus were the suckers should be and extracted those as an extra subtool. After the extraction I remeshed those dots so they were workable but I left them without further detailing other than some diffuse coloration. Since this wouldn’t be a real scientific rendition of an octopus I allowed myself some slack ;-). But I did uv map it and made the diffuse map.

Materials

That was it regarding ZBrush. I exported the parts of the model and the maps so I could import them into Blender.

If you look closely at great renditions of 3d artists you will see that a lot of the time the model itself isn’t nearly as detailed as the rendition makes you believe. That is because a good use of materials can make or break a model. That and lighting.

So I spend most of the time on tweaking the material to a point that it looks like I want it to look. The material I used is one of my base cycles materials. Not in the sense that it’s basic, but it’s a very versatile material that can be tweaked to serve different purposes. It is a material I use for complex skins and it gives me the opportunity to tweak it as if it is a real skin with dermal layers. Once I was working on it, I noticed that the ends of the arms needed some additional masks for subsurface scattering so I made a mask in ZBrush. I used the same base material for the suckers, with other textures of course.

The glass and water material are tweaked materials from Reynante Martinez CMV

And I made big use of the relatively new feature in Blender of adaptive subdivisions. If you want to make efficient use of that too, please see this video of Reynante martinez about it:

Composition

An octopus in a glass is nice and all, but what does such an image need? Since it’s an aquatic animal, water is inevitable. The glass is relatively small, so a lot goes over the edge and falls to the ground. You see the octopus in the process of getting out of the glass, were somebody put him in. So droplets are scattered all over the place and most of them hang in still air. Water is dripping from his arms onto the ground.

So that is the image I am making. Most of the droplets you see in the air are made with a particle system on the octopus itself. the droplets have different shapes and placed in a group that is randomly distributed over the arms of the octopus. On the body of the octopus an extra object is made that is the water dripping of the body itself.

I also added water in the glass itself, so you can see a realistic view of the body of the octopus through the layer of glass and water

Render

Because I put most of my time in tweaking the skin material for the octopus, I wanted to make sure I had good lighting without having to doubt what it would do. So I made it easy on myself and used the Pro Lighting Studio from Andrew Price.

That addon is a BIG time saver in most of my professional work. It gives me the time to focus on the modeling and materials rather than loose it on inventing the wheel again.

I did crank up the amount of samples but I didn’t bother to add all the passes or split the image into separate render layers. The first rendition was at the size I normally use: 1920×1080. But I saw I made two mistakes: I used a bit too much water droplets on the body and the focus of the camera was on the closest arm instead of the body. I changed both and did a rendetion at 3840×2160. That took 33 hours using 8100 samples.

Here the result without using the compositor:

Final result

And here the final result. I used a little bit of lens distortion and I despeckled it a bit. But other than that this how it looks trait out of the blender cycles render.

One Comment