Low poly characters
As a sneak peek on what it is like to work inside Colossi Games, we want to introduce some of the work being done while working on Gladiators: Survival in Rome. In this article, you will learn about the work of a 3D Modeller, specifically on character art.
Everything starts with a concept, or rather a concept art piece that showcase different applications of the model in the game. Important to note is that concept art is not final — or key — art but leaves room for interpretation to the 3D modeller and texture artist, yet displays different poses, mood, color schemes and general physique to draw inspiration from.
High Poly Model
As the first step in modelling, the artist builds a highly detailed model based on the aforementioned concept art, adds his vision on how the model would appear in the game, and add all the details – scars, hair strands, straps, muscle texture, beards and other detailed shapes of the body. As a popular tool of choice, and also used by our artists, we recommend ZBrush. While it is a little on the pricey side, its makers Pixologic have been in this sphere for more than two decades, and in professional development, convenience and comfort for artists plays a bigger role than price tag.
You can also fully expect experienced artists bringing their own palette of self-created brushes, addons from the ZBrush library and other free or paid addons. ZBrush users have myriads of ways to customize their main working tools which makes it de facto standard in the industry.
Topology & Low Poly
While many games give their filesize and memory management an afterthought, and part of the reason why some games take gigabytes to download, on mobile devices storage and memory are a bit more constrained. So when we talk about low poly modelling, we’re not only defining an art style but place the player at the forefront, with a quicker time from discovery to being inside the game with smaller download size, efficient battery usage and a clear set of instructions to artists with limiting polygons, the very fabric of models in their geometrical shapes.
So with the above mentioned high poly models as seen in the examples, we need to define the limits of details, and thus polygons. Polygon reduction not only provides the benefit of efficiency for phones but also provides a clearer and easier path to animation: It’s easier to define joints, anchors and moveable parts of a model that has a limited number of ways to animate than having to make a set of animations for Arnold Schwarzenegger twitching his left chest muscle, it’s effects on shoulder, ribcage and skin movement and still make it look natural.
So this set of limiting parameters and details is called a topology mesh: A grid model without texture that provides UV coordinates for attaching texture and defines the underlying map of texture features – almost like a planet model which then will be filled with mountain ranges and other land features.
You might ask what is UV in this context; it does not refer to the ultraviolet sun rays but to the bi-dimensional nature of the grid for application of flat texture – XYZ are the coordinates of a 3D coordinate grid, so mathematicians apparently defined the previous letters for two dimensions.
In the end we have model without texture.
So when you give the model UV coordinates, you can unwrap, cut and expand the 3D model into a plane for adding textures.
A popular technique used by artists is called baking, also known as render mapping – we transfer shadows and small details from a hi-poly model to a low poly model in the form of textures. In this way our model will weigh less, requires less light reflection calculation and rendering – thus requiring less battery power from phones – and we will not lose beautiful details from our concept. After baking, we finish the texture by hand drawing and making small adaptations especially where the texture map parts connect or shadows overlap.
The modular nature of low poly modeling and the separation of model and texture also allows us to make plenty of clothing variants and hair to make the characters of the game more playful and variative.
So, to wrap it up, you see that the work of a professional 3D Modeller goes far beyond a simple dragging of geometrical forms and manipulating them, but has the use cases and efficiency as well as scalability for artful content in mind. We will leave you with a couple more examples of the work for Gladiators: Survival in Rome.
– our Art Director and Characters 3D modeller.