This Alien Doesn’t Exist - Devlog #5

The generator is finally starting to feel like an actual biology engine.

A complete rewrite

Over the last few commits I ended up rewriting most of the generation pipeline.

The biggest change was moving away from generating “random values” and instead generating a complete genome first. That genome now controls almost every part of the creature, with everything else being derived from it.

Body plans

The generator now supports multiple body plans, including:

Quadruped
Biped
Serpentine
Insectoid
Arachnoid
Cephalopod
Radial

Instead of slightly tweaking the same creature over and over, each body plan changes how the anatomy is constructed.

Better anatomy

The anatomy generator received a pretty major overhaul.

Heads are no longer just circles with eyes attached. The generator now produces different head shapes along with procedural mouth types including:

Jaws
Beaks
Mandibles
Proboscises
Filter feeders

Limbs were also rewritten using FABRIK inverse kinematics, giving them much more natural proportions and poses.

Skin generation

Creatures now generate procedural skin patterns instead of using flat colours.

Depending on the generated genome, the renderer can produce:

Spots
Stripes
Mottled patterns

These are generated using 2D value noise and blended directly into the renderer.

Eyes

Eyes ended up becoming their own little project.

Instead of drawing circles on top of the creature, eye positions are snapped onto the creature’s surface using the signed distance field.

The generator also derives eye styles from the creature’s ecology. Predators tend to receive forward-facing slit pupils, while prey species are more likely to have wide-set horizontal pupils.

Smarter traits

Facts shown beside each creature are now derived from the generated anatomy instead of being randomly selected.

Things like locomotion, diet and vision are inferred from the creature’s proportions, making the generated information much more consistent.

Website

The website also received a complete polish.

Deep linking works correctly.
The UI has been cleaned up.

You can still share a single link and anyone opening it will generate the exact same alien.

What’s next?

There’s still a lot I want to improve.

The next big goal is making the creatures feel even more alive with better anatomical variation, richer skin patterns, rendering, and eventually a searchable species registry where every discovered alien has its own permanent page. Infact the species registry will run on a WebOs project. Can’t wait to start making that. Also I’m experimenting with rendering, I might make a new branch on github and use webgl