EYESY Simulator

EYESY Simulator desktop app showing a video synth mode rendering with knob controls and audio source selector

EYESY Simulator v1.0.0

A native desktop app for developing and previewing Critter & Guitari EYESY video synthesizer modes without the hardware.

This project is not affiliated with Critter & Guitari. I built this to aid my own mode development.

Downloads

Platform	File
macOS (Apple Silicon)	EYESY Simulator-1.0.0-arm64.dmg
Windows (x64)	EYESY Simulator Setup 1.0.0.exe

What is this?

EYESY Simulator runs real EYESY Python/pygame scripts on your computer, rendering visuals in real-time. Write, test, and iterate on modes without needing the physical hardware. It works as an EYESY emulator for development: you build the mode on your laptop, then copy it to the device when it is ready.

Features

Run real EYESY modes: Point the app at any folder of EYESY modes and load main.py scripts directly
Full pygame drawing support: circle, rect, line, polygon, ellipse, arc, lines, Surface.fill, blit, font rendering, and more
5 interactive knobs: Real-time parameter control (0.0-1.0), just like the hardware
Audio simulation: Choose from silence, sine wave, white noise, beat/kick, internet radio or load your own audio file
Audio-reactive visuals: etc.audio_in, etc.audio_left, etc.audio_right, and etc.audio_trig all work
1280×720 canvas: Matches EYESY’s native resolution with 16:9 aspect ratio maintained
No Python install required: Python 3.11 runtime is bundled with the app

Getting Started

Download and install for your platform
Launch the app and select your EYESY modes folder
Pick a mode from the dropdown and hit Start
Adjust knobs and audio settings in real-time

Modes are available from the EYESY Modes GitHub repo and Patch Storage.

Simulator vs real hardware

The simulator matches the EYESY’s drawing surface and control layout, but it does not pretend to be an EYESY. The differences that matter:

	EYESY Simulator	EYESY hardware
Canvas	1280×720	1280×720
Knobs	5 on screen, 0.0 to 1.0	5 physical
Audio	Simulated: silence, sine, noise, beat, internet radio, or your own file	Live audio input
Performance	Runs at your computer’s speed	Considerably more constrained

That last row is the one to watch. The EYESY hardware may be much more resource constrained than your development device, and the simulator does not attempt to simulate those limits. You may get a better frame rate in dev than you will on the actual EYESY. Test early and often on real hardware if you are building anything complex (learned from experience).

Hardware Compatibility

Modes written and tested in the simulator are compatible with real EYESY hardware. For best compatibility, make sure your modes:

Use etc.knob1-etc.knob5 (not bare globals)
Include import pygame at the top

System Requirements

macOS: Apple Silicon (M1/M2/M3/M4), macOS 10.15+. There is no Intel build.
Windows: 64-bit, Windows 10+

Version history

1.0.0 (February 2026): First native desktop release for macOS and Windows. Bundled Python 3.11 runtime, five knobs, simulated audio sources, and full pygame drawing support.

Source

Source for the native app is at stuart78/Eyesy-native. Neither repository carries a licence file at the moment, so the code is published but not formally licensed for reuse.

Web-based Simulator (Legacy)

The original web-based EYESY Simulator is also still available. It runs EYESY Python scripts in your browser via a Python backend that streams frames over WebSocket at 30 FPS. The native app above is the recommended way to develop modes going forward.

Common questions

Can I use the EYESY without the hardware?

Yes, for writing and testing modes. EYESY Simulator runs real EYESY Python and pygame scripts on macOS or Windows and renders the visuals in real time, so you can develop modes with no EYESY connected. You still need the hardware to perform with live audio and video output.

Is the EYESY Simulator free?

Yes. It is a free download for macOS and Windows. The source for the native app and the older web version is published on GitHub.

Do modes built in the simulator run on real EYESY hardware?

Yes. Modes written and tested in the simulator are compatible with real EYESY hardware, as long as they use etc.knob1 through etc.knob5 rather than bare globals and include an import pygame line at the top.

Do I need to install Python to use it?

No. A Python 3.11 runtime is bundled with the app, so there is nothing to install separately.

Does the EYESY Simulator work on Intel Macs?

No. The macOS build is Apple Silicon only and requires an M1, M2, M3, or M4 Mac running macOS 10.15 or later. There is no Intel build. Windows users need 64-bit Windows 10 or later.

How is the simulator different from a real EYESY?

The simulator does not reproduce the hardware's performance limits. Your computer is likely faster than an EYESY, so a mode can run smoothly in the simulator and drop frames on the device. Audio is also simulated rather than live. Test complex modes on real hardware early.