id Tech 3

Modernized id Tech 3: Vulkan renderer with PBR, validation and smoke-tested builds, and disciplined cross-platform engine work.

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

Engine pillars

1. Compatibility first — QVM + native modules, classic .pk3 / cvar / trap surface (COMPATIBILITY.md); ./scripts/q3_openarena_compat_check.sh on core builds.
2. Renderer - Vulkan 1.x path with PBR, froxel volumetrics, SSAO, MSAA/SMAA, spherical harmonics lighting, SDF HUD text.
3. Tooling - GPU detection, validation layers, performance HUD, safe mode, CI matrix builds, smoke tests and shader validation in the build. FreeUSD Git submodule (src/external/FreeUSD, default ON) for USDA import and usd_* tools. Optional Tiled Map Editor submodule (tools/tiled, GPL-2.0) for tile-based level design—not linked into the engine build.
4. Platform - Linux, Windows, macOS, Android; IPv4/IPv6 networking, modern codecs and asset loaders.

Features

Rendering:

• 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:

• MD3, MDR, IQM, OBJ, glTF / GLB, MD5, STL, DAE, FBX, USD / USDA (FreeUSD, default ON), Maya Ascii (MA) — loaders under src/renderers/vulkan/; glTF details: docs/GLTF.md
• Blend shapes: IQM and glTF morph + skeletal clips (RE_SetEntityMorphWeight, r_gltfAnim, r_morph, GPU skin/morph via r_gltfGpu) — docs/GLTF.md

Renderer (models): OBJ, glTF/GLB, and MD5 share registration and MOD_* types on the Vulkan path. glTF GPU skin/morph (r_gltfGpu, SSBOs, tangent fix) is Vulkan PBR. See docs/RENDERERS.md.

Scripting:

• Lua
• JavaScript
• Python
• C#

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)
• P2P Networking: Supports peer-to-peer server/client connections, NAT traversal, and automatic fallback for robust online sessions without central relays.
• 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)
• Optional Open OSCAR / AIM bridge (oscar_enable): hybrid direct FLAP client with buddy roster, Chat rooms, and ImGui buddy panel — see docs/OSCAR_INTEGRATION.md
• Console/logging for connection diagnostics and real-time network statistics

Systems (game and engine extensions):

• AIML 3.0 chatbot scripting (see g_aiml.c / Lua Engine.AIML)
• Goal Oriented Action Planner (AI planning)
• Flocking and boids (crowd AI)
• hierarchical State Machines (HSM), Finite State Machines (FSM), and Behavior Trees
• Navigation Mesh (NavMesh) pathfinding (A*, Dijkstra)
• Event scripting (Lua, JavaScript)
• Physics (with optional Bullet Physics or Box3D)
• 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_*.json persistence (Lua Engine.Save; legacy .txt still reads)
• 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 (x64)
• Linux (x64 and arm64)
• Android
• MacOS
• Web

Standards

• The engine aims to be C++23 and C23-compatible with modernization 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.
• Now using SDL3 as the primary multimedia and input backend

Build

Primary entry point:

./scripts/compile_engine.sh vulkan           # Vulkan + Release (game profile)
./scripts/compile_engine.sh vulkan debug
./scripts/compile_engine.sh vulkan full rtx  # experimental neural paths + KHR ray tracing (not stubbed)

Default game profile stubs research neural paths and RTX (USE_EXPERIMENTAL_RENDERERS=OFF, USE_VULKAN_RTX=OFF). Use full rtx (or research rtx) when you want those integrated at link time. DLSS/NGX remains external (use r_upscale / r_taa / driver scaling).

For direct CMake workflows, the repo also ships CMakePresets.json:

cmake --preset vulkan-release
cmake --build --preset build-vulkan-release
ctest --preset test-vulkan-release

Artifacts land under release/ and build-vk-Release/. The helper script is the canonical developer path because it stages release/ automatically; presets are the preferred direct-CMake / IDE path.

Editor

The engine features a built-in, cross-platform Editor designed for rapid development and prototyping. The Editor is available as a standalone application and also supports in-game editing modes.

Key Features:

• Visual scene and entity editor with real-time viewport rendering.
• Drag-and-drop placement and hierarchical organization of entities and components.
• Support for editing levels, prefabs, lights, navigation meshes, and physics volumes.
• Property inspector for editing component properties, including materials, scripts, and AI behaviors.
• Embedded script editor (Lua and JavaScript) with immediate feedback and live reloading.
• Integration with the engine’s asset pipeline: hot-reload assets, manage resource dependencies, and preview changes instantly.
• Timeline and sequencing tools for cutscenes, events, and gameplay scripting.
• Built-in debugging overlays, profiling tools, and real-time telemetry visualization.
• Multi-user collaborative editing support (via server-client connections).
• Extensible via plugins—extend with custom editors or workflow integrations.

Platforms:
The Editor runs on Windows, Linux, and MacOS.

Refer to the documentation or scripts/launch_editor.sh to get started with the desktop Editor.

Long-term Feature Plans

• Ray tracing (WIP)
• Path tracing
• Voxels

Links

• https://idtech3.com