ax engine

Hello,

It's been a while since our last post about Kiyo! In that occasion we announced our first trailer, and lots of cool stuff happened since then. We will soon post a new article to showcase some gameplay (finally!), but in this one we focus on the looks of the game.
Alhough, to a certain extent, this stuff is about gameplay as well, given that hiding in the shadows is one of our core mechanics!
Everything in the game is good old 2D pixel art authored in Aseprite, and we apply to it some techniques normally used in 3D games (but actual 3D assets and perspective rendering are banned).
The biggest advantage, apart from the awesome result, is the massive reduction of manual labor when drawing sprites: every item and character can be drawn only once, with neutral colors and no shading. There is a quick additional step to provide "shape" information and then the engine will render everything nicely in every possible lighting condition.

Let's get warmed up with a nice gif!

Each of the following examples is a pair of before (no effects, just the plain art with uniform brightness) and after (dynamic lighting & shading on).

Point Lights

In this first example you can appreciate how much depth and atmosphere we can add to a scene by setting up the lighting appropriately. Here Kiyo is breaking into a wealthy bunny's mansion at night, in order to steal a keycard.

Shadows, materials

In this comparison (taken from the tutorial level) you can see Kiyo's shadow (cast by his lantern and generated in real time) and the shiny metallic pipe above.

Emissive Materials, Rim Lighting, Normal Mapping

This shot comes from the bar at Club69. Again, the lighting has a dramatic impact in helping provide the right tone to the scene. Specifically here you can notice the emissiveness on certain materials, how rim lighting helps details stand out and the effect of normal mapping on giving depth to the characters.

Skeletal animations & Hi-res rendering

In addition to basic frame-based sprites, our game uses skeletal animations to provide buttery smooth movements (and reduce the amount of manual labor). Rotating things at pixel art resolution would obviously look terrible (first screenshot) and that's why, under the hood, the scene is composed into a high-resolution render target.
There's a lot of eye candy in this shot of the private underground swimming pool belonging to a rich bunny - my favourites are the tile-relief system and the rim effects on the leaves.

Volumetric lights

Yeah, we added those too, because they look pretty cool. Some of you will remember this shot from the trailer.

And that's all for now... stay tuned for an upcoming article about the gameplay!
We're planning to start an in-depth devlog about all this stuff too.

Greetings from the Pixel Rats