pck404 [Lexaloffle Blog Feed]

XOR approximation using NN

Sun, 04 Dec 2022 21:04:13 UTC

pck404_xor

by pck404

[Click to Play]

This is a visualisation of a 3-layer perceptron learning to approximate the XOR function.

At some point I would like to make an educational cart like this one to explain what's happening under the hood.

Machine learning 101 : the perceptron

Sun, 04 Dec 2022 17:34:12 UTC

Machine learning 101 : the perceptron

by pck404

[Click to Play]

Why this educart?

The perceptron is a tiny computing unit that is a fondamental block of artificial neural networks.

Because machine learning is getting more important everyday, I thought I would share the little knowledge I have in the form of a chewable educart, hoping more people would get interested in the inner workings of machine learning algorithms.

Tell me if you found this useful and if I should make more. Also, I'm not a ML specialist and English is not my primary language so any suggestions to make this cart better will be appreciated!

♥pck404

Additional cart : interact with the perceptron in real-time

pck404_perceptron_lr

by pck404

[Click to Play]

Sources and links

My main source for this cart is Daniel Shiffman's wonderful "Nature of Code" as well as the Coding Train video series on neural networks.

Changelog

Wave function collapse - Simple tiled model

Tue, 25 Oct 2022 20:12:14 UTC

pck404_wfc_stm

by pck404

[Click to Play]

This is my take on the wave function collapse algorithm in one of its simple variants : the simple tiled model.

Given a set of tiles and some adjancency rules, the algorithm tries to produce an image. It can be used for levels generation, pattern-like backgrounds and can also be used for non-visual data.

How does it work ?

This cart contains a few demo tilesets and rulesets that you can navigate between with the left and right arrows.

Sometimes the algorithm gets stuck (shown with red tiles). This happens when there is a contradiction : the rules won't allow any tile to be placed on a position. Press X or O to restart.

Yeah but, really, how does it work ?

I suggest you look at the links provided below for more information about the algorithm.

For this specific implementation, I used bitfields to encode adjacency rules : each tile has a list of 4 integers (for the four directions : up, right, down, left). Valid neighbors are determined by comparing (with a binary AND) the opposite bitfields of each tiles : 1 can connect with 1, 3 can connect with 2 and with 1,...

Campfire (trying to simulate fire)

Sat, 01 Oct 2022 23:56:04 UTC

Campfire (trying to simulate fire)

by pck404

[Click to Play]

Campfire

This is just me trying to simulate fire in Pico8 without shaders or fancy particle systems.

My approach is :

At load time :
- Generate bursts of animated particles
- Each particle increments the brightness value for the pixels it sits on
- The burst animations are baked into the spritesheet
At run time :
- Animate the baked sprites (moving them up)
- Again, add the brightness values together

The brightness value (which is just a color from 0 to 7) is mapped to a fire shade with pal().

There are other particle systems for bursts of sparkles and fireflies.

Any thought? What would be your approach?

v2 update

use colors 0 to 7 for fire shades : no table needed to store brightness values
bake animations into spritesheet for performance
got rid of smoke
add flickering
nicer fireflies and flying ember
add clouds

v3 update

press a button to toggle scene on/off (monitor CPU usage of fire only)

Fulmosago

Sun, 18 Sep 2022 17:25:15 UTC

Fulmosago

by pck404

[Click to Play]

Fulmosago

A bright yellow ship is launched at full speed across the universe.

Mission code is Fulmosago. The objective : a small and well-guarded planet.

Based on Basic Shmup Tutorial by Lazy Devs Academy.

Controls

In menus, press X or C to confirm.

In game, use arrow keys to move your ship.

The ship will shoot automatically when there are enemies. Hold C to force shoot. Hold X to prevent autoshooting.

Pickups

pink pickup restores health (or add one extra heart if health is full)
orange pickup activates double front canons
blue pickup activates side canons (auto-guided orbs)

Soundtrack

Listen to the soundtrack on SoundCloud.

About

This is my second Pico-8 game. The Lazy Devs Academy tutorial series served as a basis. From there, my main goal was to tell a simple but impactful story within a limited play time.

512px under

Sun, 12 Dec 2021 15:21:43 UTC

pck404_512px_under

by pck404

[Click to Play]

512px under

Year 4096. A burried building with lasers and traps. How many lives will it take to leave this place ?

Jump, wall jump and dodge lasers
18 memory cards to collect
32 rooms to explore (with lasers in them)
Auto-save
1 red cube
Lots of lasers !

Controls

Arrows : move
V (or X) : jump
C (or Z) : grab/drop

Move and jump

Grab and drop

Wall jump

About

This game is my first Pico-8 game. It is also the first game I manage to finish after a few attempts with game engines such as Unity and Godot. It took me 1 month to complete the first published version. The Pico-8 restrictions allowed me to define a manageable scope for this game. In the end, I used the entire space available in the map editor and the spritesheet editor. The code uses every token allowed.

pck404 [Lexaloffle Blog Feed]

XOR approximation using NN

Machine learning 101 : the perceptron

Why this educart?

Additional cart : interact with the perceptron in real-time

Sources and links

Changelog

Wave function collapse - Simple tiled model

How does it work ?

Yeah but, really, how does it work ?

Links

Campfire (trying to simulate fire)

Campfire

v2 update

v3 update

Fulmosago

Fulmosago

Controls

Pickups

Soundtrack

About

512px under

512px under

Controls

Move and jump

Grab and drop

Wall jump

About

Changelog