id Tech 3

Modern id Tech 3: Vulkan-first renderer with PBR, optional OpenGL fallback, validation and smoke-tested builds, and disciplined cross-platform engine work. Everything below extends that core.

This repository does not contain any game content from Quake III Arena.

Engine pillars

1. Renderer — Vulkan 1.x path with PBR, froxel volumetrics, SSAO, MSAA/SMAA, spherical harmonics lighting, SDF HUD text; OpenGL renderer remains for compatibility.
2. Tooling — GPU detection, validation layers, performance HUD, safe mode, CI matrix builds, smoke tests and shader validation in the build.
3. Platform — Linux, Windows, macOS, Android; IPv4/IPv6 networking, modern codecs and asset loaders.

Ray tracing (Vulkan RT) is scaffolded / in progress — see docs/RENDERERS_FUTURE.md and CLAUDE.md for status, not a headline guarantee.

Features (by area)

Rendering:

• OpenGL renderer (fallback)
• Vulkan renderer
• Physically Based Rendering (PBR)
• Spherical Harmonics lighting support
• Screen Space Ambient Occlusion (SSAO)
• High-quality SDF HUD text rendering with UTF-8 glyph support
• SVG asset rasterization (NanoSVG / NanoSVRast, built-in; no extra system libs)
• Froxel-based Volumetric Lighting with 2D Navier–Stokes fluid solver
• MSAA and SMAA anti-aliasing

Audio:

• OpenAL backend with HRTF for 3D positional audio
• Real-time reverb and occlusion effects via OpenAL EFX (heuristic environmental acoustics)
• Audio codec support: mp3, ogg, wav, flac, webm, opus

Video:

• Video codec support: RoQ, WebM (VP8/VP9), Ogg Theora, MP4 (H.264)

Models:

• Model formats supported: MD3, MDR, IQM, OBJ, FBX, GLTF, USD (Universal Scene Description), Maya Ascii, Collada (DAE), STL
• Blend Shapes (IQM, GLTF)

Scripting:

• Support for Lua scripting
• Support for JavaScript scripting

Images:

• Image format support: PNG, JPEG, TGA, BMP, DDS, WebP, HDR, OpenEXR (EXR), KTX, PKM, PVR

Image Generation (optional):

• FLUX.2/FLUX.1 C image generation (text-to-image from console, real-time hot-reload, device selection; supports flux1-schnell, flux1-dev, flux2-dev; requires model files in game directory; Metal, BLAS, or pure C backend with graceful fallback)

Networking:

• Full IPv6 and IPv4 dual-stack support (host, client, server)
• NAT traversal (UDP hole punching with automatic fallback strategies)
• Server discovery: LAN broadcast and master-server queries
• Built-in rate limiting/DDoS mitigation (connection flood protection)
• Challenge/response protocol with replay/spoof resistance enhancements
• Reliable UDP virtual channel (sequenced/reliable message streams)
• Asynchronous non-blocking networking (epoll/kqueue/libsockets abstractions)
• Graceful automatic fallback to IPv4-only if stack or OS configuration requires
• DTLS (Datagram TLS) for secure UDP when enabled at runtime (net_dtls + net_dtls_key; OpenSSL linked when available at build time)
• Optional TLS-secured remote console (off by default)
• Console/logging for connection diagnostics and real-time network statistics

Systems (game and engine extensions):

• AIML 2.1-oriented chatbot scripting (see g_aiml.c / Lua Engine.AIML)
• GOAP (AI planning)
• Flocking and boids (crowd AI)
• Finite State Machines (FSM) and Behavior Trees
• Navigation Mesh (NavMesh) pathfinding (A*, Dijkstra)
• Event scripting (Lua, JavaScript)
• Physics and collision (with optional Bullet Physics)
• Multithreaded scheduler/task system
• Entity-Component System (ECS, ENTT)
• Replay frame index tied to server snapshots (engine_replay; Lua Engine.Replay)
• Save slot metadata + save/engine_slot_*.txt persistence (Lua Engine.Save)
• Dynamic dialogue and quest stage tracking (Lua Engine.Dialogue, Engine.Quest)
• Procedural/random systems
• Statistics / player telemetry counters (Lua Engine.Telemetry, cvar engine_telemetry; distinct from renderer GPU counters)
• Debugging tools and overlays

Platforms

• Windows
• Linux
• Android
• MacOS

Standards

• The engine aims to be C23-compatible, and modernization is ongoing where it improves safety and portability.
• Native C bool is preferred in new or modernized code, but qboolean remains in use where needed for backward compatibility.

Build

Primary entry point:

./scripts/compile_engine.sh vulkan    # Vulkan + Release
./scripts/compile_engine.sh opengl   # OpenGL fallback
./scripts/compile_engine.sh vulkan debug

Artifacts land under release/ and build-vk-Release/ (or build-gl-Release/). Run tests from the build directory: ctest or make test.

Examples (copy-paste workflows): examples/README.md — local validation, GAME_BASE templates, mod launch lines, pointers to docs/samples/. Demo mod pack (optional CMake): -DBUILD_EXAMPLE_DEMO_GAME=ON then build target demo_game_pk3 → idtech3_demo.pk3 (examples/demo_game/README.md). Run demo from a source tree: ./scripts/run_demo.sh — see examples/demo_skeleton/README.md.

Renderer discipline: docs/RENDERER_CONFIDENCE.md, headless ./scripts/renderer_regression_check.sh, visual pack specs under docs/samples/renderer_regression/.

Links

• https://idtech3.com
• https://github.com/jksunny/quake3e