Powder Game

A GPU-first powder sandbox built in C++20 with OpenGL 4.3 compute shaders.

1000 x 1000 simulation grid, real-time materials, and a multiphase compute pipeline for sand, water, smoke, fire, and heat.

About

Powder Game is an experimental real-time simulation project focused on a fully GPU-driven architecture.

• Tech stack: C++20, OpenGL 4.3+, compute shaders
• Design goal: rich multi-material interactions without CPU readback in the frame loop
• Scope: sand, water, smoke, fire, heat, and cross-material coupling
• Platform support: Linux and Windows 11 (standalone package flow included)

Why This Project

This project focuses on one goal: keep the simulation on the GPU and maintain interactive performance while layering multiple coupled systems.

Features

• Sand with Verlet-style motion + conflict-resolved movement
• Water via D2Q9 LBM at full resolution
• Smoke stable-fluid style solver at quarter resolution
• Fire reaction-diffusion + half-res heat coupling
• Cross-material coupling passes (fire/heat/smoke/water/sand)
• No CPU readback in the frame loop
• Active-tile culling pass to skip heavy work in idle regions
• Tuned texture formats (smoke density in R8) to reduce bandwidth
• Windows packaging script for standalone .exe output

Controls

• 1: Sand brush
• 2: Water brush
• 3: Solid brush
• 4: Erase brush
• 5: Smoke brush
• 6: Fire brush
• [ / ]: Brush radius down/up
• Left Mouse: Paint
• Esc: Quit

Quick Start (Linux)

cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j
./build/powder_game

Notes:

• OpenGL 4.3+ is required.
• Dependencies are auto-fetched by CMake if not available as system packages.

Windows 11 Standalone Build (from Linux)

Build and package a Win11 x64 zip:

./build-win11.sh

Output:

• dist/win11/PowderGame-win11-x64.zip

Pipeline Overview

Per-frame compute flow:

1. Spawn/input pass
2. Sand pass (prepare, desired, resolve, commit)
3. Water LBM pass + pressure extraction
4. Smoke pass (advect, vorticity, project)
5. Fire + heat passes
6. Coupling passes
7. Composite render

Project Layout

• src/: C++ app and GL utilities
• shaders/: compute + render shaders
• PLAN.md: architecture and milestone plan
• build-win11.sh: Win11 standalone packaging

Current Status

Milestones 1-7 are implemented from PLAN.md.

Current focus areas:

• simulation tuning and visual polish
• deeper active-tile compaction strategies (indirect-dispatch path)

Build Philosophy

• GPU-first orchestration
• SoA-friendly texture layout
• explicit memory barriers between passes
• ping-pong resources for solver stability