EchoTools Demo Viewer

A Unity-based replay viewer for EchoVR demo files.

Originally created by David Robidas (@robidasdavid) and Zzenith (2020). This is the EchoTools fork -- the most actively maintained version.

Supported Formats

Format	Source	Container
.echoreplay	Spark / legacy capturer	JSON + zstd (ButterReplays v1-v3)
.nevrcap	nEVR platform	Protobuf v1 + zstd
.tape	echotools/tapedeck CLI	Protobuf v2 + zstd (Envelope stream)

Requirements

• Unity 6000.3.x (Unity 6) -- project targets 6000.3.4f1
• buf -- protobuf toolchain (generates C# from .proto definitions)
• just -- command runner (optional, for build shortcuts)
• git-lfs -- binary assets are stored with LFS

Building

Prerequisites

• Unity Hub with Unity 6000.3.x installed
• buf (protobuf codegen)
• just (command runner)
• git-lfs

Linux (Arch):

pacman -S just git-lfs
# buf: https://buf.build/docs/installation
buf_version=1.50.0 && \
  curl -sSL "https://github.com/bufbuild/buf/releases/download/v${buf_version}/buf-Linux-x86_64" -o ~/.local/bin/buf && \
  chmod +x ~/.local/bin/buf

Linux (Ubuntu/Debian):

sudo apt install git-lfs
# just
curl --proto '=https' --tlsv1.2 -sSf https://just.systems/install.sh | bash -s -- --to ~/.local/bin
# buf (same as above)

Windows (winget):

winget install Casey.Just
winget install GitHub.GitLFS
winget install Bufbuild.Buf

Clone

git lfs install
git clone https://github.com/EchoTools/demo-viewer.git
cd demo-viewer

Linux

# Check prerequisites
just doctor

# Generate C# from protobuf definitions
just proto

# Build
just build-linux

# Output: Build/Linux/ReplayViewer

Unity must be installed at ~/Unity/Hub/Editor/6000.3.4f1/Editor/Unity, or set UNITY_PATH:

UNITY_PATH=/path/to/Unity just build-linux

Windows

# Check prerequisites
just doctor

# Generate C# from protobuf definitions
just proto

# Build
just build-windows

# Output: Build\Windows\ReplayViewer.exe

Unity must be installed at the default Hub location, or set UNITY_PATH:

$env:UNITY_PATH = "C:\Program Files\Unity\Hub\Editor\6000.3.4f1\Editor\Unity.exe"
just build-windows

Other Commands

just build-macos     # macOS build
just build-all       # all platforms
just test            # run Unity tests
just clean           # remove build artifacts + Unity cache

Usage

Launch the built executable. Open the menu (tilde key) and select a replay file or paste a path. For VR mode, launch with -useVR.

Keyboard

Key	Action
WASD	Camera movement
Q / E	Descend / ascend
Shift	Speed boost
Mouse wheel	Adjust speed

Controller (Xbox)

Input	Action
Left / right stick	Movement / look
LB / RB	Descend / ascend
A	Play / pause
D-pad left / right	Rewind / fast-forward
Triggers	Analog scrub

Project Structure

Assets/
  Scripts/
    GameManager.cs            Singleton entry, scene/mode management
    Game.cs                   Core game-state logic
    ReplayLoader/Replay.cs    Frame playback driver
    ButterReplays/            .echoreplay decompressors (v1-v3)
    NevrCap/                  .nevrcap reader + frame converter
    Tape/                     .tape v2 reader + frame converter
    EchoVRAPI/                Data model (Frame, Player, Team, Disc, etc.)
    Network/                  VelNet multiplayer (shared viewing)
  Scenes/
    Game Scene.unity          Primary replay scene
    Greenscreen.unity         Chroma-key compositing
  Plugins/                    Runtime DLLs (Protobuf, ZstdSharp)
  Prefabs/, Models/           3D assets
  Arena_V3/, Arena V4/        Arena environments
Packages/                     Unity package manifest
ProjectSettings/              Unity project settings
proto/                        Protobuf definitions (managed by buf)
justfile                      Build recipes (just --list)
buf.yaml / buf.gen.yaml       Buf module + codegen config

License

GPL-3.0 -- see LICENSE.