Various improvements

[pragmaware]

This PR contains several improvements including texture packing speed-ups, geometric error estimation, tile overlap, glb support, setting presets and some bug fixes. Look at the individual commits for more information.

I am aware of the fact that this is complicated to evaluate and merge. It's the result of a work I'm doing on a real project and unfortunately I didn't have time to make smaller PRs. You can merge it as it is, cherry-pick some commits, use some as inspiration or ignore everything altogether...

However, the bugfixes are certainly useful. Also the direct *.glb support is interesting because it then allows to run the draco encoder on each tile significantly reducing the output size.

[gojushin]

Woah. Geometric error estimation and .glb support, are two things I already planned to also look into, some time in the future!
Good stuff!!
This would also set the stage for potential future 3d-tiles 2.0 compatibility!

[Copilot]

Pull request overview

This PR extends Obj2Tiles’ pipeline (Decimation → Splitting → Tiling) with new output/quality controls and several geometry/MTL/texture-handling improvements, including support for emitting plain GLB tile content (3D Tiles 1.1) and more robust geometric-error estimation.

Changes:

• Add GLB tile output path (alongside legacy b3dm) plus CLI preset support and additional CLI knobs.
• Introduce per-tile metrics (TileBounds) and new geometric error estimation modes/factors used by the tiling stage.
• Improve splitting/texture/material handling (tile overlap + deterministic nudge, normal-map parsing/ignoring, texture subfolder fallback, texture quality controls) and performance tweaks (bin pack prune optimization).

Reviewed changes

Copilot reviewed 35 out of 35 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
TODO	Adds roadmap notes for future work
README.md	Documents new CLI options and defaults
Obj2Tiles/Utils.cs	Enhances dependency copying and adds GLB conversion
Obj2Tiles/Stages/TilingStage.cs	Adds GLB output and geometric-error estimation modes
Obj2Tiles/Stages/TileBounds.cs	Introduces per-tile bounds + edge metrics record
Obj2Tiles/Stages/SplitStage.cs	Propagates overlap/normal-map/quality options; returns TileBounds
Obj2Tiles/Stages/Model/ObjMesh.cs	Optimizes OBJ writing via attribute deduplication
Obj2Tiles/Stages/DecimationStage.cs	Adds decimation modes and normal-map ignore option
Obj2Tiles/Program.cs	Adds preset application and wires new options through pipeline
Obj2Tiles/Options.cs	Adds many new CLI options (preset, GLB, overlap, error modes, etc.)
Obj2Tiles.Test/ThreeTzArchiveTests.cs	Updates tests for TileBounds mapping
Obj2Tiles.Test/StagesTests.cs	Updates stage tests; adds dependency-copy fallback test
Obj2Tiles.Test/ObjParserGltfTests.cs	Adds tests for normal-map parsing and glTF validity
Obj2Tiles.sln.DotSettings.user	Updates Rider user settings file (likely accidental)
Obj2Tiles.Library/Materials/Material.cs	Adds texture-subfolder fallback and normal-map aliases/ignoring
Obj2Tiles.Library/Geometry/VertexUtils.cs	Canonicalizes edge endpoints to avoid split cracks
Obj2Tiles.Library/Geometry/Vertex3.cs	Fixes equality implementation and epsilon usage
Obj2Tiles.Library/Geometry/Vertex2.cs	Switches equality epsilon to Common.Epsilon
Obj2Tiles.Library/Geometry/MeshUtils.cs	Adds overlap splitting + deterministic nudge; MTL ignoreNormalMaps
Obj2Tiles.Library/Geometry/MeshT.cs	Adds Translate, edge metrics, UV island logic fixes, normal map PNG handling
Obj2Tiles.Library/Geometry/Mesh.cs	Adds Translate and edge metrics
Obj2Tiles.Library/Geometry/IMesh.cs	Extends interface with Translate and edge metrics
Obj2Tiles.Library/Geometry/Box3.cs	Adds Diagonal() helper
Obj2Tiles.Library/Common.cs	Replaces unusable epsilon with machine epsilon constant
Obj2Tiles.Library/Algos/MaxRectanglesBinPack.cs	Optimizes free-rectangle pruning performance
Obj2Tiles.Library.Test/MtlParsingTests.cs	Adds tests for normal-map aliases and texture-subfolder fallback
Obj2Gltf/WaveFront/MtlParser.cs	Adds bump/map_Bump support for normal maps
Obj2Gltf/GltfConverterOptions.cs	Adds UnlitMaterials option
Obj2Gltf/Gltf/Material.cs	Adds material Extensions dictionary support
Obj2Gltf/Converter.cs	Adds unlit material support; fixes normal-map-only TEXCOORD emission
MeshDecimatorCore/SimplificationOptions.cs	Updates defaults/docs for vertex link epsilon and UV seam/foldover docs
MeshDecimatorCore/Math/Vector4d.cs	Updates epsilon constant to machine epsilon
MeshDecimatorCore/Math/Vector3d.cs	Updates epsilon constant to machine epsilon
MeshDecimatorCore/Math/Vector2d.cs	Updates epsilon constant to machine epsilon
MeshDecimatorCore/Algorithms/FastQuadricMeshSimplification.cs	Adds verbose decimation statistics logging

Comments suppressed due to low confidence (3)

Obj2Tiles/Stages/TilingStage.cs:412

• The XML docs state ToplevelAverageEdgeLength defaults to --error-factor 0.5, but ResolveErrorFactor() defaults edge-length modes to 1.0. Please update this docstring to match behavior.
  Obj2Tiles/Stages/TilingStage.cs:418
• The XML docs state ToplevelMaximumEdgeLength defaults to --error-factor 0.5, but ResolveErrorFactor() defaults edge-length modes to 1.0. Please update this docstring to match behavior.
  MeshDecimatorCore/SimplificationOptions.cs:49
• Doc comment typos: “An UV … EnableSmarkLink … boders” should be “A UV … EnableSmartLink … borders” for clarity and to match the actual property name.

        /// An UV foldover edge is a border edge that is duplicated in two distinct
        /// triangles with same UV coordinates (likely normal-related vertex duplication).
        /// This is relevant only if EnableSmarkLink is set to true.
        /// If EnableSmartLink is set to false the UV foldover edges are always treated as boders.
        /// Default value: false

[HeDo88TH]

I think we will soon need a separate documentation website!

[HeDo88TH]

I am ready to merge it @pragmaware but, since it is a pretty large PR, do you have any benchmark for these changes?