SkyRender

OpenGL rendering for Skyrim NIF scenes, in two packages:

• SkyRender (net8.0): NIF parsing, Bethesda materials and shaders, DDS textures (decoded or authored-mip compressed uploads), CPU skinning, the GL renderer with overlays, and an offscreen pipeline that renders a scene to PNG or raw BGRA32 pixels. No WPF and no game-library dependency.
• SkyRender.Character (net8.0-windows10.0.19041.0, WPF): character assembly on top of the core: NPC mesh-path inputs, texture and mesh overrides, FaceGen heads, slot occupancy, an NPC offscreen scene builder for portraits, and an interactive viewer view model with WPF panels.

The libraries take no dependency on Mutagen.Bethesda or other game-record libraries. A host implements a few small abstraction interfaces so the renderer can pull the data it needs:

• IBsaArchiveProvider — finds and extracts files inside BSA archives.
• IDataFolderProvider — supplies the game Data folder and a cache token.
• IRenderLogger, IRenderSettings — logging and cache sizing.
• Character tier: INpcMeshDataSource (resolves an NPC to its mesh/texture paths) and ICharacterViewerSettings (extends IRenderSettings with the viewer's persisted settings).

Quick start

var resolver = new GameAssetResolver(myDataFolder, myBsaProvider, logGate, logger);
var assets   = new AssetCache(resolver, logger, logGate);
var shapes   = assets.MeshBuilder.BuildFromFile(@"C:\path\to\model.nif");   // any thread

// On the GL thread:
var renderer = new GlRenderer();
renderer.Initialize(ModuleResourceLocator.ShaderDirectory);
var textures = new GlTextureManager(assets, logger);
textures.Initialize();
foreach (var shape in shapes)
{
    var mesh = GlMeshFactory.Create(shape);
    NifMaterialBinder.Bind(textures, resolver, mesh, shape, shape.TexturePaths, new MaterialBindOptions());
    renderer.AddMesh(mesh);
}
renderer.Render(camera, width, height);   // every frame

Offscreen rendering, NPC portraits and the interactive character viewer are covered in the usage guide.

Demo

Three sample apps show the library at work:

• samples/SkyRender.Demo is a minimal WPF viewer: choose Open NIF…, and it renders the mesh with its textures (resolved from the game's Data folder and archives), framed automatically, under the studio lighting the character tier uses (Game daylight switches to the scene look). Drag to orbit, middle-drag to pan, use the wheel to zoom.
• samples/SkyRender.CellDemo draws a whole interior or exterior cell of the installed game: terrain, water, grass, statics, effects, weather or cell lighting, and optionally distant LOD.
• samples/SkyRender.CharacterDemo lists the NPCs of the installed game and draws the one you pick with their default outfit, in the interactive character viewer.

dotnet run --project samples/SkyRender.Demo
dotnet run --project samples/SkyRender.CellDemo -c Release
dotnet run --project samples/SkyRender.CharacterDemo -c Release

The comparisons below put a SkyRender frame beside the game's own screenshot from the same camera position, drawn from the base game's data. The screenshots are of The Elder Scrolls V: Skyrim Special Edition, a game by Bethesda Game Studios, captured for illustration. Exteriors are under the vanilla clear weather at noon.

Riverwood from the air: terrain with its painted layers, the river, buildings and trees of the cells in view.

The view north from above Riverwood, with distant terrain, object and tree LOD beyond the loaded cells.

A meadow near Riverwood at eye level, with grass placed by the engine's rules (the exact tufts differ: the game's placement is not repeatable).

The Bannered Mare's kitchen hearth: the cell's own lighting, its placed lights with shadows, and the fire's effect-shader flames turned toward the camera.

Known differences: grass is still brighter than the game's; particles (sparks, smoke, the hearth's moving flames) and NPCs are not drawn; the game's distance haze is thicker; no bloom or eye adaptation; and clouds are not drawn. RENDERING_PIPELINE.md records each comparison.

Platform

• Windows with an OpenGL 3.3 capable GPU (the offscreen renderer requests a 4.0 core context).
• The core is plain net8.0; the character tier needs WPF and a Windows platform version of at least 10.0.19041 in the host's target framework (for example net8.0-windows10.0.19041.0; a plain -windows target gets NU1202). USAGE.md's Troubleshooting section explains this and the harmless MSB3246 warning from the NIF library's native DLL.
• GLSL shaders ship embedded in the assembly (and are also copied beside it for local builds), so the package works as a PackageReference with no extra setup.

Documentation

• Usage guide
• Rendering pipeline: how NIF data flows through parsing, materials, lighting and post-processing.
• Character pipeline: what SkyRender.Character adds: NPC inputs, overrides, the interactive viewer.
• Changelog

Authorship

SkyRender was created by Piranha91 together with Claude, Anthropic's AI model. Piranha91 directed the design, set the requirements, validated the results against the game and reviewed every change; Claude wrote the code. No code in the initial release was written by hand.

Acknowledgements

SkyRender builds on nifly by ousnius, NiflySharp by SteveTownsend, Mutagen by Noggog, and Community Shaders by doodlum and contributors, whose HLSL lighting code was partly ported to GLSL and made character skin tint match the game. Details and the other libraries used are in NOTICE.md.

License

GPL-3.0-only.