Skip to content

MeshLabProcess.md

Latest commit

 

History

History
47 lines (38 loc) · 3.56 KB

MeshLabProcess.md

File metadata and controls

47 lines (38 loc) · 3.56 KB

MeshLab Process

Import .ply Point Cloud File

  • Import the pointcloud file as .ply into MeshLab File -> Import Mesh
  • See CloudCompareProcess.md for details on generating a clean pointcloud

Simplify Point Cloud and Compute Normals

  • Reduce number of points for smooth remeshing.
    • Filters -> Point Set -> Point Cloud Simplification. Enter Number of samples to be ~5% of original number of points. Make sure Best Sample Heuristic is checked.
  • Make sure the Simplified point cloud is selected in the Layer Dialog (right). It might be prudent to save this mesh as a file File -> Export Mesh. The file each layer is saved as is in the detail of the Layer Dialog (click the >). Changes to layers are not saved until export mesh is run on that layer.
  • Compute normals Filters -> Point Set -> Compute normals for point sets. Neighbor num between 10-100, initially try 10. For Smooth Iteration, initially try 0 (5-10 may give better results).
  • Make sure normals are properly computed by going to Render -> Show Normal. Should display many blue lines If blue lines are on exterior of room, then normals need to be inverted (see below)

Generate Mesh with Poisson Surface Reconstruction

  • Filters -> Remeshing, Simplification and Reconstruction -> Surface Reconstruction: Screened Poisson. Initially use default parameters, but can be adjusted.
    • This should create another layer called Poisson. Make sure this layer is selected for further operations
  • The meshing may have created extra surfaces. To remove them, Filters -> Selection -> Select Faces with edges longer than .... The default value is automatically computed. Click on apply. Delete faces by clicking on the delete face button (triangle face with three vertices with cross over it).
  • Some noise may still persist. Filters -> Cleaning and Repairing -> Remove isolated pieces (wrt Face Num.). Use the default value, and make sure Remove unreferenced vertices is checked
  • Final cleaning option Filters -> Selection -> Select non Manifold Vertices. Click apply. then click on delete face button.
  • Additional cleaning of mesh can be manually done by using Select Faces in a rectangular region.
  • It is a good idea at this stage to Export Mesh the poisson layer as .obj.

Generate Texture for Mesh Using Point Color Data

  • Convert the vertex color to a texture
    • Filters -> Texture -> Per Vertex Texture Function. Click apply.
    • Filters -> Texture -> Convert PerVertex UV into PerWedge UV. Click apply.
    • Filters -> Texture -> Parametrization: trivial Per-triangle.
      • Quads-per-line: 0
      • Texture Dimension: 5000 (maybe more, see below)
      • Inter-triangle border: 0 (maybe more, see below)
      • Method: Basic (sometimes Space-optimizing crashes)
      • Click apply.
    • Filters -> Texture -> Transfer: Vertex Color to Texture
      • Texture file: (file name for .png)
      • Texture width: Same as Texture Dimension
      • Texture height: Same as Texture Dimension
      • Check Assign texture and Fill texture
      • Click apply.
    • Export mesh for changes to apply
  • There should now be three files generated: a .obj file (containing the mesh), a .png (containing the texture), and a .mtl (material file for joining them). These three files are used in Blender, Unity, Unreal, etc.

Additional Considerations

  • If the texture generated appears to have mis-colored borders around the triangles, one solution may be to increase the texture dimension size and inter-triangle border.