Geocore Stellar Engine

A GPU-accelerated procedural skybox engine for low-earth orbit simulation. Generate photorealistic space backgrounds — complete with the Milky Way, 100K+ catalog stars, 88 IAU constellations, volumetric nebulae, sun with god rays and lens flare — then export as cubemap PNGs or HDR for Unity and other game engines.

Built for Geocore — a 3D modern educational geography game, using a camera perspective from low-earth orbit.

Links

Screenshots

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Features

Render Layers (10 layers)

Feature	Description
Milky Way	Physically-based galactic plane with customizable tilt, core brightness, and arm structure
Catalog Stars	119,614 real stars from the HYG v4.2 database with accurate B-V color mapping and magnitude-based sizing
Procedural Stars	100K+ seeded point sprites with adjustable count, brightness, size, and color variation
Nebula	Volumetric 4D simplex noise FBM with 3-color gradient, tunable density, falloff, and octaves
Sun	Directional light with disk, corona, limb darkening, and atmospheric glow
Constellations	All 88 IAU constellation lines, labels, and boundary polygons
Named Star Labels	Labels for prominent named stars (Sirius, Betelgeuse, Polaris, etc.)
Background	Solid color fill layer

Post-Processing Pipeline

Feature	Description
God Rays	Volumetric light scattering with radial blur + cross-face analytical glow
Bloom	Multi-pass Gaussian bloom with configurable threshold, soft knee, and iterations
Lens Flare	Analytical ghost elements, halo ring, anamorphic streaks, and chromatic aberration

Export Formats

Feature	Description
Individual Face PNGs (ZIP)	6 cubemap faces at up to 8K resolution
Cross Layout PNG	Single 4:3 composite image
HDR (Radiance RGBE)	High dynamic range cubemap export
Tiled Rendering	GPU-friendly tile-based rendering for 8K/16K+ exports without VRAM limits
Batch Export	Export all presets in one operation

Editing & Workflow

Feature	Description
Preset System	5 built-in presets + save/load/import/export custom presets (JSON)
Undo/Redo	Full parameter history with keyboard shortcuts (Ctrl+Z / Ctrl+Shift+Z)
A/B Comparison	Side-by-side before/after comparison with split slider
Session Persistence	Auto-saves all parameters to localStorage; restores on reload
Real-time Histogram	Live RGB histogram with async GPU readback (no stalls)
Performance Monitor	FPS/frame time/render time overlay

Graphics Engine

Feature	Description
WebGL2 + GLSL 300 es	Hardware-accelerated rendering pipeline
10-layer compositing	Sorted render layers with per-layer enable/disable
Cubemap FBO	Renders all 6 faces with shared framebuffer
Async Readback	PBO-based pixel readback with fence sync for stall-free histogram

Author

Anahat Mudgal · GitHub · Geocore Technologies