Introduction

Screen Pet Engine is a desktop app that puts small animated characters, called pets, on your screen. They walk along the bottom of your display, sit above your Dock or taskbar, and you can pick them up and drop them wherever you like. You can run the pets that come with the app, or create your own.

There are three ideas at the heart of the app:

• Play. Turn a pet on and it comes to life on your desktop, following its own behavior. Turn it off when you are done.
• Create. Design a pet from your own artwork: import sprites, then wire up a visual behavior graph that decides what your pet does.
• Share. Export a pet or object as a bundle to hand to a friend, and import ones they send you.

Screen Pet Engine running a pet along the bottom of the screen, with the Library open behind it.

Two ways to use the app

If you just want desktop pets, you only ever need two windows:

• the Library, where you browse pets and switch them on or off, and
• the pet windows themselves, one small transparent window per live pet.

Everything else (the editor, importer, slicer) is optional. Playing pets is lightweight: closing the Library does not stop your pets, and you never have to open the editor.

If you want to build your own pets, the app becomes a small creative studio: a sprite Importer, a sprite-sheet Slicer, a node-based behavior graph editor, and an Object Editor for scenery. Part 2 of this manual walks through all of it.

What is in this demo

Area	What you get
Bundled content	19 pets and 27 objects, ready to use
Pet behaviors	Idle, Walk, and weighted-random branching, plus always-on drag and fall
Editor nodes	Start, End, Idle, Walk, Random (5 types)
Sprite tools	Import from PNG sequence, GIF, or sprite sheet; grid slicer
Objects	Static and animated scenery with animation states and layers
Sharing	Export pets and objects as bundles (.spe / .speo) and import ones others send you
Platforms	macOS and Windows
Languages	English, 日本語, Español, 繁體中文, 简体中文

Note on names

The download is called “Screen Pet Engine Demo”, but inside the app (window titles, the About screen) it is just “Screen Pet Engine”. Same app; this manual uses the short name.

What is not in this build

So you are not left hunting for features that are not here yet, the demo does not include: extra action types (run, sit, sleep, eat), pet-to-object interaction and navigation nodes, anchor points, or event nodes (on-click, on-timer). These may arrive in later releases.