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?

[pragmaware]

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

Hi, I've developed and tested these changes on various large and complex models I'm working on. Mostly drone photogrammetry, often quite messed up. Different creator software, different settings, different exports, different hands...

You can view some of them at https://monumentidigitali.artcentrica.com . Keep in mind that this is a testing website and not all the models have been generated with the same Obj2Tiles version. I think that MANM and Vulci are the latest.

Unfortuntately I'm not able to share the source models as they aren't mine and I don't have the permission to distribute them.