The game’s overall visual style vaguely resembles a microscope image of cellular structures, but with slightly more vibrancy and colour. Generally, realism should be favoured unless such a design would be highly unintuitive (for example, real world cells are mostly transparent, but having the player use a fully transparent microbe in an environment filled with fully transparent microbes would make gameplay difficult). There should also be influences from less realistic science fiction aesthetics, especially in the design of the GUI.
There are several rules of thumb to stick to when designing all game assets:
- Pseudo-randomness – Textures should look like they have a definite order or set of rules, but should also look organic. Examples include Perlin Noise, Voronoi Textures (especially in regards to the GUI) and real world organism texturing.
- Uniform sharpness – Texture should either contain bold, sharp edges, medium sharpness edges or soft edges. Edge types should not be mixed: try sharp edges first, then blur them to the desired degree. While microscopic images have several levels of focus, this is due to the distance of objects away from the viewpoint, achievable by varying appearance relative to the game camera. Individual objects should always have a uniform focus.
- Light, desaturated colors – Microbes usually have this type of coloration because they’re small and mostly transparent, so there isn’t much pigment to build or create dark colors. This should be kept in mind when deciding on organism coloration.
- Realistic color types – Cell coloration should avoid purples, pinks, or yellows, as these aren’t often found in nature. Instead, the focus should be on blues, greens, reds, and pale oranges – the following color palette options are all prime examples of this range (accented in white to reflect the translucency):
Main Article: Microbe Stage GUI
The GUI is based on a “shard” design – individual panels or buttons should look like shards of broken glass with a somewhat organic appearance (like a Voronoi Texture, or reptilian scales). For the most part, it should be minimal, with as little screen interference as possible. Hence why many GUI elements (such as the quick menu and compounds panel) can expand and contract from the screen corners.
Panels should be positioned close to one another with small, consistent gaps between them and bevelled edges. Each panel shows one or two major pieces of information, often using icons to convey information instead of words (for example, save is a stylized floppy disk).
All panels are turquoise and translucent. Icons and text should be primarily white, except in cases where more colors are needed like the ATP bar or compound level radar charts. Whenever a compound is represented in any way, its associated color and/or symbol should be used to distinguish it.
GUI animations are generally simple. Depending on what type of panel they are, they may appear instantaneously or gradually. Examples of the first are the pause menu and help panel, while the second is used for any expandable menus or panels. Any element which appears gradually will slide onto the screen and fade in to give the sense that it’s growing outwards from a point.
In any situation where the game is paused, the entire game screen is covered with a grey overlay except for any GUI elements in focus. The exception is manual pausing using the spacebar – this only brings up the organelle priorities, not an overlay.
Buttons are GUI panels which can be clicked. When hovered over or clicked, they should highlight in green.
There are two types of 3D models used in the game: static and procedurally generated.
Static models have pre-defined shape throughout all situations, so can be created by modelers beforehand.
There are various static model needs:
- Organelles – All internal organelles will retain their shape while floating around inside microbes. For the nucleus, mitochondria, chloroplasts, etc. only a single model is needed for each. Coloration will vary as organelles are damaged (flashing red) or function faster (more color vibrancy), but they patterns are unchanging. External organelles do change form, but in exact animations, discussed in the next section. Periphery organelles consist of a shader applied to the whole microbe, covering it in cilia for example.
- Bacteria – Bacteria (or prokaryotes) do not have procedural membranes or organelles besides flagella, so can be created beforehand. Each bacteria type needs a different appearance, though this can mostly be a different color scheme (e.g. cyanobacteria are blue-green).
Procedural models are created and updated by the game on the fly based on environmental or player input. There are several rules for creating each, and pre-made visual elements can be used (such as patterning on a membrane), but the exact mechanics describing how each may be generated are explained in the simulation specifics section.
Like static models, procedural models come in many types:
- Membranes – Membranes are perhaps the most complex example of procedural generation within the game, relying on multiple factors. Initially, a microbe’s membrane is drawn based on its cytoskeletal hex structure, before becoming flexible and taking a more natural appearance. Cytoplasm area should be near enough the same between the hex arrangement and procedural shape, and should retain some aspects of what the player or Auto-Evo has decided a microbe is shaped like. Protruding lines of hexagons, for instance, need to remain about the same length and position. A further complication in drawing a membrane is that a microbe’s shape is defined in 2D, but the model needs to be rendered in 3D. Thickness should vary intuitively, i.e. thicker towards the center of a microbe and thinner at the edges, before curving over at the edges to an unseen underside. Membranes are overlaid with patterning and coloration, which also can’t distort too drastically. Environmental distortion also affects membranes. If a microbe pushes into another, its leading edge should squash. Similarly, the edges of a membrane may be affected by water currents, making streamlined organisms more effective.
- Surfaces – A surface is any inorganic object in the environment, such as rock or ice (the latter appearing during snowball Earth disaster events). All surfaces have the same uniform thickness, but their outer edges are generated procedurally. There are very few constraints on their form, but they shouldn’t exceed a certain size.
Main Article: Microbe Animation
Most of the animations required for the microbe stage are for organelles. Though technically static models, they do exhibit dynamic behavior, but unlike the procedurally generated models, this behavior is pre-planned. The only difficulties arise when changing between different animations.
Movement organelles oscillate to drive cells forward through the environment. Flagella should either twist (like twirling springs) or wiggle (like a moving sine curve), animator’s choice. Cilia are similar, but much smaller, so will only change direction a couple of times along their length within one oscillation (unlike flagella, which do this multiple times). Lamellipodia should look and animate like a crowd of stumpy legs, changing their direction of oscillation depending on which way the microbe is travelling. The rate of oscillation for every organelle should scale with speed, becoming zero when not in use.
Other external and periphery organelles need simple animations. Pili should extend and retract organically but quickly, while agent secretors should compress slightly when secreting agents. All membrane animations are discussed in the previous section.
Internal organelles aren’t animated, other than their random floating around inside membranes. They may exhibit gradual changes of color depending on their rate of function or health level.
Main Article: Microbe Backgrounds
For the microbe stage, the background will generally be the oceanic floor. Depending on the biome, its visuals will change. Thus several different background textures are required.
All backgrounds must feature a tiling pattern with no discernible gaps between panels. The patterning itself needs to be complex but inconspicuous, and doesn’t necessarily need to look completely natural. While no in-game microbes can become colonies until the end game, backgrounds can feature biofilms or similar biological structures, but no macroscopic organisms. Everything should be at a microscopic scale, with the foreground appearing to be only slightly raised from the background.
As the player swims, the background should remain stationary (moving relative to the field of view), so it appears that the player is moving across the seafloor. There may be some slight movement to give the illusion of parallax, but this will have to be calibrated to give a realistic distance between the foreground and background.
A background must be sized so that its tiling isn’t clear, even when a player has zoomed out to the maximum extent.
Transitioning between biomes will gradually fade the backgrounds of the two together through transparency.
Some examples of effective backgrounds for different biomes:
Between the foreground and background is the midground, which shows the paths of water currents and compound clouds. Water currents are distinguished by slight variances in water shading and lighting to give the impression of ripple or waves. The water is mostly transparent other than these tints.
The midground may also have a few organisms in it (as microbes don’t necessarily travel over a single plane), but the player and other foreground microbes will be unable to interact with them. All midground objects must be obscured by the water currents and heavily blurred to show this distinction.
Main Article: Compound System
Whenever a compound or agent spills into the environment, it produces a compound cloud. These are tied into the grid representation of compounds, where each point has an associated level of each compound. Higher concentrations have a more vibrant compound cloud of their associated color (e.g. oxygen’s color is light blue, so compound clouds of oxygen are light blue). The only exception is water, which is transparent and doesn’t change visually whatever its density.
Compound clouds can mix, and billow following the path of water currents. Gradually they'll become less dense as they spread out, eventually becoming invisible after a certain point. When a microbe enters a compound cloud, it may collect the compound if it has enough storage or processing space. This reduces the concentration of that compound in the area the microbe has traveled over, lightening it slightly.
Due to some compounds being more common than others, the scale for how vibrant a compound cloud is should not be the same for all. Oxygen is far more common in the environment than calcium, for instance, so it should require a higher concentration to achieve the same color intensity.
Agents are special case compounds. The color of each agent varies, but as of yet the exact coloration hasn’t been determined. There should be some visual cues involved – lure and signal type agents should appear positive (greens) while damaging agents should be negative (reds). Agents must not be mistaken for compounds, and vice versa.