Phase 3 — High-Resolution Texturing (Metashape + 3DSC Scripts)

This phase applies high-resolution textures to the segmented tiles produced in Phase 2 — Mesh Segmentation (Blender + 3DSC). Texturing happens in Agisoft Metashape via the 3DSC for Metashape script package, which computes the optimal number of textures per tile using the Demetrescu-d’Annibale formula (see Texture resolution formula).

3.1 Prepare Metashape Project

Create a clean Metashape project for texturing:

  1. Open original Metashape project (located in 05_RB/02_PROCESSING/metashape/)

  2. File > Save As with a new name in the same folder:

    • Original: 05_RB/02_PROCESSING/metashape/project.psx

    • New: 05_RB/02_PROCESSING/metashape/project_texturing.psx

  3. Optional: Remove unnecessary chunks to simplify

  4. Ensure you have:

    • Aligned cameras

    • Sparse point cloud

    • NO mesh in the chunk (we’ll import tiles)

EM Structure Locations

  • Raw photos: 05_RB/01_RAW/photos/

  • Metashape projects: 05_RB/02_PROCESSING/metashape/

  • Import tiles from: 05_RB/03_Model_Library/[ModelName]/meshpoly/

  • Export textures to: 05_RB/03_Model_Library/[ModelName]/meshpolytex/

For the complete file-by-file location guide, see File locations — Digital Replica reference.

Photo Selection Strategy

For optimal texturing quality:

  • Use a subset of high-quality photos for texturing

  • Separate “geometry photos” (many, all angles) from “texture photos” (fewer, optimal lighting)

  • Avoid blurred images

  • Ensure consistent lighting

3.2 Install 3DSC for Metashape Scripts

  1. Download 3DSC for Metashape from GitHub:

    https://github.com/[repository-link]/3DSC-for-Metashape

  2. Extract to a known location (e.g., Desktop)

  3. The package contains several Python scripts:

    • import_multiple_models.py - Import mesh tiles

    • texturize_it.py - Automatic texturing

    • export_multiple_models.py - Export textured results

    • rename_chunks.py - Utility script

3.3 Import Mesh Tiles

  1. In Metashape, go to Tools > Run Script

  2. Select import_multiple_models.py

  3. When prompted, select the 05_RB/03_Model_Library/[ModelName]/meshpoly/ folder

  4. The script will:

    • Create one chunk per tile

    • Import each OBJ into its chunk

    • Maintain naming structure

img/metashape_chunks.png

Fig. 23 [SCREENSHOT: Metashape workspace showing multiple chunks, one per tile]

Note

The script reads all OBJ files from the selected folder. Ensure only the segmented tiles are present in meshpoly/ before running the import.

3.4 Automatic Texturing

Now apply high-resolution textures using the texture formula:

  1. Tools > Run Script

  2. Select texturize_it.py

  3. The script calculates the optimal number of textures per tile using the Demetrescu-d’Annibale texture resolution formula. For a complete derivation and worked examples, see Texture resolution formula.

Texture Settings

The script automatically configures:

  • Texture size: 4096×4096 px (adjustable)

  • Mapping mode: Generic

  • Blending mode: Mosaic

  • Enable hole filling

  • Enable ghosting filter

  1. Wait for texture generation (can take several minutes per tile)

img/texturing_progress.png

Fig. 24 [SCREENSHOT: Metashape showing textured tile preview]

3.5 Export Textured Tiles

  1. Tools > Run Script

  2. Select export_multiple_models.py

  3. Set export folder to 05_RB/03_Model_Library/[ModelName]/meshpolytex/

  4. If using georeferenced coordinates, provide shift file

  5. The script exports:

    • OBJ files (mesh geometry)

    • MTL files (material definitions)

    • PNG textures (high-resolution)

img/meshpolytex_folder.png

Fig. 25 [SCREENSHOT: File explorer showing meshpolytex folder in EM structure with OBJ, MTL, PNG files]

Storage Considerations

The meshpolytex folder can be quite large (500 MB - 2 GB for typical models).

  • Store on NAS if available (as per EM guidelines for 05_RB)

  • Consider creating a cloud link rather than direct sync

  • Keep local copy for active work, archive to NAS when complete

See also