Art Spotlight: Hydra

Hello everyone!

My name is Thanos Bompotas. I am a character & props 3D artist from Athens, Greece. I ‘ve been sketching since I can remember and picked up 3D modeling as a hobby in 1995. Even though I studied Industrial Product & Systems design in Greece, my masters was in Games Animation at Sheffield Hallam University in 2009 and it was there that I got familiar with the main applications I use in my work today, 3D Studio Max and Zbrush. I started working professionally in late 2010 in Gameloft’s studio in Madrid and I had been working there until late 2017. While I was there, I had the opportunity to work on many different titles developed by all the different studios of Gameloft around the world, among which was the in-studio developed title “Gods of Rome”. Currently I am working as a freelancer back in my home country.

The idea.

Designing creatures and especially nasty ones (hehe) has always been my favorite theme. Since Greek mythology features so many awesome and cool creatures, I decided to model one of them. I had already modeled Hercules when I was in Gameloft, I thought why not give him a monster that he actually fought in his adventures to “play” with? So I decided to do my own take on the infamous Hydra! Now I know what most of you are thinking: “Your model is not a Hydra! Each head has its own body!”
That’s true!

I could be cheeky and reply that I made 3 Hydras before their initial heads are cut off, but no, I am going to do the grown up thing and take ownership of my idea! :p

So like I said. It’s my own take on the mythical creature. More specifically, I wanted to combine reality with fiction. So I was thinking “what could the ancient Greeks have seen in real life that inspired them to come up with the idea of a multi-headed snake monster?” and the image of a snake pit came into mind with dozens of serpents, all bundled up together, looking like one organism.

The challenge.

In this project, the idea was to try to achieve as much detail inside Zbrush and try to pass it as best as I could on the final lowpoly mesh. Transferring the details of the highpoly sculpt is a challenge on its own.

But with the specific creature the problem is that it has a really long body. In my first attempt I sculpted the whole body of the Hydra and when the time came to bake onto the lowpoly, I tried fitting everything in one UV layout and just hoping for the best, using a 4k texture. As soon as I baked the normal map I realized that a lot of details from the highpoly sculpt were being lost with this approach, so I had to think of an alternative plan.
Initially I thought that simply separating the head from the body, and dedicating a 4k texture to each part would be enough, but of course that attempt failed big time, since the body has 10 times the length of the head and the difference in texel density between them was too obvious.

So I went for the most tricky solution, which between you and me, I was trying to avoid since the beginning. A modular body!

Having the body consist of the same one piece, with a 4k texture on it, repeating 10 times was really efficient in terms of resolution. The problem was that I somehow had to align the scales of the front part of the modular piece to fit exactly with the scales of the back part, but on top of that, they had to fit with the scales of the back part of the head of the Hydra!

Initially I thought that this would be a nightmare to pull off, thinking that I would have to constantly go back and forth between the highpoly and the lowpoly, fixing misalignments and texture coloring problems, but it was easier than I thought. Notice that I said “easier” not “easy”. So bear with me as I go through the process..

First I took the highpoly I had at that moment and cut the head following the flow of the scales:

I then projected this new highpoly onto the lowpoly I had up to that point, to help me see where I had to cut the lowpoly to match the high.

After the head was done, it was time for the tricky part: the modular body. I started first with the problem of aligning the front and back scales of the modular piece. In order to make this easier on myself, I made a small piece first, and after I was sure the scales were more or less aligned, I replicated it 2 more times and made the final module by welding them together as you can see below:

Now that I had the lowpoly of the modular piece, it was just a matter of sending it into Zbrush to subdivide it and make the highpoly version of it.

In the end the modular pieces fitted together perfectly and the only problem of alignment was at the connection with the head, which is not perfect but it’s good enough to sell the effect. To be honest I didn’t believe that this would work, and I was expecting really obvious seam cuts at the places the modular pieces join, but it actually worked better than expected! Granted you can see the pattern repetition on the body and under specific light/camera angles, the place where the head and body meet becomes obvious, but overall I think it’s acceptable and it was a nice personal experiment.

But that was just part of my experimentation in this project. The other part was to see how I can add as much micro detail on this creature as possible. As much as I like sculpting, I have realized that trying to achieve micro details in Zbrush is pointless. In order to get it you need to subdivide the geometry far too many times, most probably on more than just one subtool and that results in extremely big files in every aspect – memory and space on the hard drive. Not to mention that I have set auto-save every five minutes in Zbrush, and when a file is so big you have to wait 40-50 secs on every auto-save. Not only that, but let’s say that memory and space is no problem for your super beefed up PC, and you manage to achieve micro details in Zbrush. Congrats! Now you need to export all of these millions of polys, preferably without decimating them, because then all these micro details would melt away, and once you do, you have to bake all of these millions of polys. So good luck with that. In short I found out, micro details are better left to be done in programs such as Substance Painter. In this project I used a Peeled Paint effect on the scales of the hydra to add micro details on them.

It is definitely much faster, less resource intensive and good for your sanity ; )

The Pose and Diorama.

I had worked with the PathDeform modifier in 3dsMax and I knew how powerful it is and what I can do with it. This is what I used to tangle the 3 snakes together in such a complicated way. Without this modifier, it would be a nightmare to manage. The animation of their bodies is just a value inside the modifier going up and down and the opening and closing of their mouths is made by using morph targets. The rattling of the 3rd one’s fins is made using a Wave modifier which affects only the fin area with a soft selection of vertices. I used the wave and ripple modifiers to make the geometry of the water too. In order to pass the effects of all of these modifiers inside Sketchfab you must export using the Alembic format (.abc).

Sketchfab is a great platform to host your 3D models that is constantly evolving, but is already really powerful. For this project I was really excited to use the SSS effect on the Hydra’s fins and tongue and the Refraction on the lake water! I cannot wait to see what the Sketchfab dev team has in store for us in the near future!

Also I would like to give a big thank you to the support team that is always there and always responds in a friendly manner to any issues, questions, suggestions that I have had over the time.

And of course I really appreciate the promotions my models get from the Sketchfab staff, in the form of being staff-picked, posted on social media, being part of the week’s top 10 most viewed, or of course being asked to write about the process of their production like I am doing right now : )

Thank you all for taking the time to read this article and thank you SF team for all that you do for the 3D art community!

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