erhe

A C++ 3D graphics library and sandbox editor, with a Vulkan/Metal-style rendering abstraction over OpenGL, Vulkan, and Metal.

erhe is an actively-developed personal research project for real-time rendering and geometry. Its editor is a sandbox for 3D scene creation, manipulation, and procedural mesh generation. erhe is the evolution of RenderStack.

git clone https://github.com/tksuoran/erhe
cd erhe

# Windows (from an x64 Native Tools Command Prompt)
scripts\configure_vs2026_vulkan.bat

# Linux
scripts/configure_ninja_linux_vulkan.sh && cmake --build build_ninja_linux_vulkan --target editor

# macOS
scripts/configure_xcode_metal.sh && cmake --build build_xcode_metal --target editor --config Debug

Vulkan is the default backend; the OpenGL build uses the *_opengl scripts instead (e.g. scripts\configure_vs2026_opengl.bat). See doc/building.md for all backends, CMake options, and IDE setup.

The OpenGL backend requires OpenGL 4.1 at minimum (the maximum available on macOS); 4.6 is recommended. See doc/opengl41_compatibility.md for the compatibility layer.

The editor is a sandbox application for 3D scene creation and manipulation.

• Multiple 3D viewports with independent camera and rendering settings
• Hierarchical scene graph with node parenting
• glTF import and export
• Scene serialization to JSON with companion binary glTF
• Multi-scene support
• Post-processing pipeline (bloom, tonemapping)
• Shadow mapping
• PBR material system with metallic/roughness workflow
• Material library with preview rendering

• Fly camera -- 6DOF camera navigation with WASD, orbit, tumble, track, zoom
• Selection -- click-to-select with shift/ctrl multi-select, GPU ID buffer or raytrace picking
• Transform gizmo -- translate, rotate, scale with axis/plane constraints and snapping
• Brush placement -- place shapes on surfaces with snap-to-face, rotation, and scale-to-match
• Vertex painting -- paint vertex colors directly on meshes
• Material painting -- assign materials to individual mesh faces
• Physics interaction -- drag, push, and pull rigid bodies in the scene
• Grid -- configurable grid display and snap-to-grid

• Subdivision: Catmull-Clark, sqrt3
• Conway operators: ambo, chamfer, dual, gyro, join, kis, meta, truncate, chamfer/bevel
• CSG / boolean: union, intersection, difference (experimental, via Geogram)
• Utilities: triangulate, normalize, reverse, weld, repair, generate tangents, bake transform
• Full undo/redo for all operations

• Parametric shapes: sphere, box, cone, torus, disc, cylinder
• Brush system with reusable shape templates
• 180+ built-in polyhedra (Platonic solids, Johnson solids, geodesic domes, etc.)
• Procedural scene generation

• Texture graph -- Material Maker-style procedural texture authoring with ~75 node types (noises, patterns, gradients, transforms, color operations); nodes compose into a single fragment shader evaluated on the GPU, with live per-node previews, and bake to textures and PBR material channels
• Geometry graph -- node-based procedural modeling: parametric generators, subdivision, Conway operators, lattice deform, boolean CSG, point scattering and instancing, nested node groups; evaluated asynchronously on worker threads so editing stays interactive
• Shared node-editor canvas with a dockable node palette, undo/redo, and JSON serialization; graphs are content-library assets

• CPU ray tracing library with swappable backends (madmann91 bvh, tinybvh, Embree 4) and BVH disk caching, used for mouse picking and spatial queries
• GPU ray tracing renderer (Vulkan ray query compute): PBR material shading, real scene lights, ray-traced shadows, reflection and refraction for transmissive materials

• Progressive GPU lightmap baker (ray query compute): direct lighting, indirect bounce, procedural sky lighting, texel supersampling
• Automatic lightmap UV unwrap with world-space quadtree tile partitioning and per-tile atlas packing
• Artifact defenses: conservative-raster texel G-buffer, JNLM denoise, seam blending, dilation, shadow terminator fix
• Tiles persist to disk and stream in by camera distance under a fixed memory budget, so world size is unbounded
• Bakes progressively in the running editor; lighting and geometry edits invalidate and re-accumulate automatically

• glTF 2.0 import and export (via fastgltf)
• Partial support for Wavefront OBJ import

• Headset rendering with OpenXR
• Hand and controller tracking with visualization
• Floating HUD and hotbar UI in VR
• Passthrough support

• Keyboard and mouse with configurable bindings
• SpaceMouse 6DOF input
• OpenXR controllers

• Debug line and text rendering in 3D viewports
• Physics shape visualization
• Render graph visualization window
• Shader hot-reload via shader monitor
• GL state dump to clipboard
• Tracy profiler integration
• Built-in MCP server: scene inspection and editing, screenshots, and tool automation for AI-agent and scripted workflows — see AI creations for agent-built showcase scenes and the editor features they exercise

erhe is organized as a set of independent libraries under src/erhe/. Each has a notes.md with details on purpose, API, and design.

erhe targets OpenGL 4.6 with DSA but includes a runtime compatibility layer for OpenGL 4.1 (the maximum version on macOS). Features like DSA, SSBOs, compute shaders, persistent mapping, and texture views are emulated or gracefully degraded at runtime. See doc/opengl41_compatibility.md for details.

erhe's own source is MIT-licensed -- see src/erhe/LICENSE. Bundled and fetched third-party dependencies retain their own licenses; see License.txt for the overview.

erhe stands on many excellent open-source projects, including Dear ImGui, Jolt Physics, Geogram, fastgltf, simdjson, SDL, OpenXR, FreeType, HarfBuzz, Tracy, GLM, fmt, and spdlog. Dependencies are fetched at configure time via CPM.cmake.

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