Add mesh texture mapping

[ahojnnes]

Based on Waechter, Michael and Moehrle, Nils and Goesele, Michael. "Let there be color! Large-scale texturing of 3D reconstructions." European Conference on Computer Vision, 2014.

Current vertex-based coloring with 16M faces:

New texture-based coloring with 0.4M faces:

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Summary of Changes

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This pull request adds a new feature to COLMAP for mapping textures onto 3D mesh models using multiple images. It includes a new command-line tool, options for customization, and integrates with existing COLMAP components. The changes enhance the visual quality of reconstructed 3D models by applying realistic textures derived from the input images.

Highlights

• Mesh Texture Mapping: This PR introduces mesh texture mapping functionality to COLMAP, allowing users to apply textures to 3D mesh models using calibrated multi-view images.
• New Executable Command: A new mesh_texture_mapper command is added to the COLMAP executable, providing a command-line interface for performing mesh texture mapping.
• Option Manager Integration: The PR integrates mesh texture mapping options into the OptionManager, allowing users to configure various parameters such as minimum normal angle, visible vertices, and smoothing iterations.
• CGAL Dependency: The implementation uses CGAL for occlusion testing, which improves the quality of texture mapping by avoiding occluded regions. A warning message is displayed when CGAL is disabled.

Changelog

• src/colmap/controllers/option_manager.cc
  • Added include for texture_mapping.h
  • Added mesh texture mapping options
  • Added a method to add mesh texture mapping options
  • Reset mesh texture mapping options
  • Reset mesh texture mapping options struct
  • Added a check for mesh texture mapping options
• src/colmap/controllers/option_manager.h
  • Added MeshTextureMappingOptions struct
  • Added a method to add mesh texture mapping options
  • Added mesh texture mapping options as a shared pointer
  • Added a boolean to check if mesh texture mapping options were added
• src/colmap/exe/colmap.cc
  • Added mesh_texture_mapper command
• src/colmap/exe/mvs.cc
  • Added include for model.h and texture_mapping.h
  • Added RunMeshTextureMapper function
• src/colmap/exe/mvs.h
  • Added RunMeshTextureMapper declaration
• src/colmap/mvs/CMakeLists.txt
  • Added texture_mapping.h and texture_mapping.cc
  • Added texture_mapping_test.cc
• src/colmap/mvs/texture_mapping.cc
  • Added new file for mesh texture mapping implementation
• src/colmap/mvs/texture_mapping.h
  • Added new file for mesh texture mapping header
• src/colmap/mvs/texture_mapping_test.cc
  • Added new file for mesh texture mapping tests
• src/colmap/util/ply.cc
  • Added include for string.h
  • Added ReadTexturedPlyMesh function
  • Added WriteTextTexturedPlyMesh function
  • Added WriteBinaryTexturedPlyMesh function
• src/colmap/util/ply.h
  • Added include for string
  • Added PlyTexturedMesh struct
  • Added ReadTexturedPlyMesh declaration
  • Added WriteTextTexturedPlyMesh declaration
  • Added WriteBinaryTexturedPlyMesh declaration
• src/colmap/util/ply_test.cc
  • Added CreateTestTexturedMesh function
  • Added VerifyTexturedMesh function
  • Added RoundTripTextTexturedPlyMesh test
  • Added RoundTripBinaryTexturedPlyMesh test
  • Added ReadTexturedPlyMeshWithoutTexcoords test

Activity

• The pull request introduces a new feature for mesh texture mapping.
• The implementation includes view selection, atlas packing, texture baking, and color correction.
• The code leverages CGAL for occlusion testing to improve texture quality.
• The changes include modifications to option management, command-line execution, and PLY file I/O.

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Code Review

This pull request introduces a comprehensive mesh texture mapping pipeline, including view selection for each mesh face, texture atlas packing, texture baking from source images, and an optional global color correction step to reduce seams. A critical security concern has been identified: a potential Denial of Service (DoS) vulnerability in the atlas packing logic due to integer overflows in atlas dimensions calculation, which could lead to an infinite loop. This requires immediate attention, ideally by using larger integer types and implementing dimension limits. Furthermore, the review highlights areas for improvement such as potential rendering artifacts from a loose threshold in texture baking, an unimplemented Poisson blending option, and a performance suggestion for the linear solver in color correction.