Designing New Creatures
Hello Riftbreakers!
The development of the third World Expansion for The Riftbreaker is well underway. We stream our progress previews on Twitch from time to time, testing the new survival mode setup and the basics of the new biome’s gameplay - follow www.twitch.tv/exorstudios to catch us live! As you know from one of our previous articles, the development of an update or an expansion is a lengthy process. It’s full of trial and error and involves a lot of iterations over various elements we want to include in the game. Today, we would like to tell you what it looks like in the case of 3D graphics. We will take a look at a couple of new creature models, what they looked like initially, why they were rejected, and what kind of improvements our artists made to make them viable. Today we’re looking at the technical side of things only - these cute little creatures will get a proper introductory article when the time is right. With all that out of the way - let’s see what the process looks like.
Some of the new creatures are quite menacing, but aren't aggressive.Please note that there is much more to creating new creatures than we can cover with just one article. After designing and modeling the creature, we need to create textures, animation rig, create animations themselves and program the unit’s behavior that will make use of those animations. After that, we add a whole bunch of effects. All blood splats, projectiles, and any other visuals produced by the creature are custom-made for that unit. Same goes for sound effects - they are all created on a per-unit basis. Then, after all the technicalities are done, we can finally playtest the game including the new unit, tweak its behavior and balance it in the context of gameplay as a whole. This article will only cover the process of getting from the concept phase to the final, high-poly model.
...unless you come too close for their comfort.The work starts with the concept. During the pre-production phase, after we have decided on the general theme of the new biome, we run a series of design meetings where we come up with ideas for the fauna and flora you’re going to find in the area. While plants and other props are designed to support the general theme and serve as decoration, creatures need to fit both thematically and functionally. We gather tons of references, looking at our favorite works of science fiction, other games, and all other media that could be even remotely relevant to the theme of the biome. We come up with several designs and decide what kind of units we need for the new area when it comes to function. We usually need a light ground unit to appear in large numbers, a medium-sized ranged unit, a tank, and a couple of special units with unique mechanics. Our designs for the large tank and the small cannon-fodder came first.
Stickrids are so delicate you can just stomp them.Fungor is the first of them. The initial design for the creature was to make a tall, menacing hybrid of an animal with a mushroom. Fungor’s design is supposed to make you ask yourself ‘what is going on here?’, as the creature tries to rip the mecha-suit apart and consume you with its giant jaws. Our artists came up with several propositions, trying to solve the issues of Fungor’s proportions, anatomy, movement, and attack mechanics. These are the first concepts they came up with.

Ahhh, sweet man-made horrors beyond comprehension. Everything immediately fell into place after these concepts were presented to the team. We chose elements that we liked from each version. What we wanted was a fungal abomination that moves in an upright position using massive tentacles. We also decided to add another tentacle to the back of the creature that it can use as a weird whip/hammer hybrid. With these assumptions, the artists got back to work. A couple of days later we got this beauty:
Fungor in its ‘rigging pose’ - all the appendages are extended as far as they go and add the animation rig to the model. Essentially, Fungor is T-posing here.
Designing Fungor was rather straightforward. There was no need to go back and do a couple of redesigns - when a clear vision clicked in our heads, it was only a matter of time before our art team could make it a reality. The scale, anatomy and form all match the desired function of the creature. However, things do not always go so smoothly. This little guy is called a Stickrid:

Hey, this is a Stickrid, too…

And this one as well…
The notes next to the arrow say: [top] the tail fin is helpful when living in a swamp. and [lower, next to the hand] fangs so that the creature can climb.Here, we got three wildly different concepts. After some discussions and looking deep into the beautiful googly eyes of number 1 and number 3, we decided that number 2 was the only one we wanted to kill. However, number 2 had its fair share of problems. First of all - it resembled a spider a little bit too much and we are aware that not everyone would jam with this idea. Second - the spider-like anatomy meant that the creature’s body would be very low to the ground. In the case of the swamp biome, that’s not really what we wanted, as the critter would not be visible to the player most of the time. We decided to merge some ideas from number 1 and number 2 into one model and lengthen the legs. This way the creature would resemble a grasshopper more and its body would stick over the surface of the water.
Stickrids' design allows us to place them directly in bodies of water.Another thing is the creature’s function. Even though it falls into the ‘cannon fodder’ category - it’s small and always comes at the player in relatively large numbers - it is different from the other small creatures in the game. Instead of melee attacks, Stickrid prefers ranged combat. It will run away from its target to a safe distance and try to take it down with a barrage of small projectiles. If you try to come closer, the creatures will scatter around, trying to keep their distance from you. This feature means that the creature needs to look like it’s able to launch projectiles. Unfortunately, this eliminates the cute number 3. Goodbye, Frogozaurus Rex.

This was the first attempt at merging the first two concepts. The legs have changed significantly, but we were still not very happy with the overall body shape. We decided that the abdomen, also known professionally as the ‘spider butt’ should be slimmed down. We thought that the creature would look beter in a ‘cigar’ shape.

After all of these changes we arrived at this concept. All our goals have been met:
- It has an elongated body and no longer resembles a spider
- Long legs ensure that the creature will not hide beneath the surface of the swamp
- The gaping mouth is ready to shoot projectiles at you and your base
- It’s not cute anymore and we have no problems killing it.
All that’s left is to add some detail and final polish to the model. Here’s the final version:
If you compare the last two versions of the Stickrid we presented, you will easily see the difference between the sketch and the final hi-poly model. When going for the ‘final quality’ model, artists pay a lot more attention to the anatomical details of the creatures they model. The legs have been beefed up, and their joints have been moved slightly to make the model more lifelike. The legs themselves no longer stick out of the abdomen. Now, both these elements flow naturally from one to another. Stickrid’s body has also become more compact, ensuring it behaves as intended in large groups, which is the intended use case. Apart from these touch-ups, the creature also received a lot more details. Ribbed carapace, sharp feet, and striped antennae on the head - we have to skip all these things when coming up with low-poly concepts.
One Stickrid is not that threatening...Artists at EXOR have complete freedom when choosing references and style for their models. The design team only gives them broad descriptions of what kind of creature they think will work well gameplay-wise. Everything else is up to the artist. Our way of creating game art is not for everyone. Some people prefer to make models based on concept art, since that more-or-less guarantees that nothing they create goes unused. However, we believe that when artists can interpret the creature description freely and create something from the ground up is our strength. It always leads to interesting results and gives them a chance to put a personal touch on their work.
...but there is never just one!So there we have it - an overview of the first steps that our models take, from the humble beginnings to the final hi-poly model. Let us know if you would like to hear about all the other stages of creature development - texturing, animations, particles, sounds, and everything else! We’ll gladly share more info on this. Remember to join our Discord at www.discord.gg/exorstudios for more news and daily changelogs. Also join our streams at www.twitch.tv/exorstudios - we haven’t streamed our co-op progress for a while, so it might happen soon…
See you next time!
EXOR Studios
Blender. Throughout this article, you will see what we're working on at the moment. Pay attention to details!
Zbrush. New creatures are coming to life right as you're reading this!
Substance Painter is where all models get their colors. And materials. And basically, everything else that makes them not look like an unpainted Warhammer mini.
Photoshop. Layers, keyboard shortcuts, 20 gigs of RAM usage. Photoshop in a nutshell.
After Effects. Even the animations you can see in the game's main menu were born in After Effects.
Visual Studio and Visual Studios Code. For non-programmers out there: spot 5 differences.
SVN keeps track of all changes ever made to a file. You can't hide your mistakes, even if you really want to!
TeamCity. This list goes on and on, as we have multiple configurations for all platforms and all our games there.
REAPER. After a little while you stop seeing weird shapes and start seeing sounds. Is this synesthesia?
Notepad++. You can edit the majority of the game's files in this program. Very much recommended.
Paint dot net. Photoshop for people without talent or skills. Or both!
Fun Fact #1: The promo art for this biome featuring Drilgor arrived when we were quite deep into the development process, when we had the creature's appearance finalized.
Fun fact #2: the first destructible rocks were reused props from the Metallic Valley biome.
Survival gameplay is never an afterthought - in fact, we have survival ready before the campaign starts to take shape.
Even playing with a limited and prototypical creature set can give us valuable insight into what we want the biome to look like.
At this stage we also learn how to build new map tiles.
There's always going to be a massive battle at some point during the campaign. The big question is - how do we get there?
We design and test various objectives. The ones that are potentially problematic are discarded to make place for better ones.
Some new tech items have to wait for the proper treatment a little longer than others. Here you can see the Acid Spewer Towers in their final form. However, the traps around the base are just recolored Acid traps.
Fun Fact #3: Drilgor had a bug that rendered it unable to hit more than one target at a time. It became a killing machine that wrecks your walls only after it was described as 'weak' in playtesting.
Fun Fact #4: The 'Brittle' achievement used to be possible only with Level 1 Crystal Walls. Luckily, we caught that pretty quickly.
No bugs in this GIF, only a lot of explosions.
The addition of Volumetric Lighting came in the final weeks of the project. It added a lot of character to the biome.
A LOT of character. We even rerecorded the entire trailer, even though some scenes were good already.
The cycle started anew, with World Expansion III now in the works. You can help us by dropping a wishlist here:







A sample scene we used for development. It features multiple sources of light, which sets a good benchmark for us.
64 layers of the light scattering model data generated from the sample scene. They are presented one by one, going from the bottom to top.
The same data presented after the light scattering transmittance accumulation step. You can see the influence that the underlying layers have on their neighbors.

Sample scene from the Jungle biome.
Sample scene from the Magma biome.
Sample scene from the Caverns biome.
Sample scene from the Acid biome.