Mesh

The following processing options can be adjusted when enabling the mesh generation:

• Input (Optional)
• Template
• Texture size
• Deghosting
• Decimation
• Sky mask
• Exports

 

Information: The Mesh can be visualized directly in PIX4Dmatic, in the 3D view. To access the 3D view:

• In the menu bar, click View > Switch to 3D, or
• Click the 3D button on the screen , or
• Use shortcut 3.

It can also be uploaded to PIX4Dcloud, for visualization. For more: How to upload or replace results to PIX4Dcloud.

Mesh 3D visualization in PIX4Dmatic.

Input (Optional)

It allows selecting the input point cloud for the Mesh generation. The following options are available:

• Dense point cloud (default): The point cloud generated from images during the Densify step.
• Depth point cloud: The point cloud generated from LiDAR depth maps.
• Depth & dense fusion: The point cloud that present a fusion of the dense and depth point cloud. 

Selecting input point cloud for the Mesh generation.

Template

This option enables distinguished default parameters for the mesh generation algorithms used for the different types of datasets imported into the software. The following templates are available for the Mesh generation:

• Aerial (default): Ideal for scenes with larger extent. Typically drone flight size projects that contain oblique or nadir data.
• PIX4Dcatch: For projects with limited extent. Optimized for hand-held captured data with PIX4DCatch.
• Thin structures: For projects that capture thin structures, i.e., cables, powerline tower structures, antennas.

Selecting Template for the Mesh generation.

Texture size

Texture Size (1024x1024 - 32768x32768 pixels, default 8192x8192 pixels): Parameter used to define the resolution of the texture of the Mesh.

Deghosting

This option enables different parameters for the mesh generation algorithms used for the different types of datasets to improve the mesh results. It can remove objects and can be beneficial in case of highly complex geometries. The following deghosting options are available for the Mesh generation:

• Weak (default): Ideal for soft outlier detection. Recommended in general cases. It may cause artifacts though, with moving objects or thin structures such as cables, powerline tower structures, and antennas.
• Strong: Aggressive outlier detection. May give better results when the geometry is highly complex (e.g. telecom towers) or when a lot of objects are moving in the scene (e.g. pedestrian street). The downside of the strong setting is that it could cause desaturation of color and loss of sharpness.

Comparison between Strong (left) and Weak (right) deghosting settings for the Mesh generation.

Decimation

Decimation (1.000.000 default): The maximum number of triangles in the final Mesh. The number will depend on the geometry and the size of the project.

Sky mask

Sky mask utilizes the generated mask during the Densify step to improve the mesh quality. It is enabled by default when the Sky filter option is enabled while running the Densify step.

Enabling the Mesh Sky mask option after selecting the Sky filter process of the desification.

Exports

From the Exports section, the following can be exported after processing the Mesh step:

• Point cloud from mesh .laz
• Mesh

Pointcloud from mesh .laz

PIX4Dmatic allows the generation and export of point clouds from the mesh. The default Density (pts/m³) or a customized one can be selected while exporting the new point cloud from the mesh. The expected point cloud size and the total number of points are also displayed while exporting the point clouds. This way, a point cloud is generated even for areas that are not directly reconstructed and holes no longer exist in the reconstructed point cloud. The point cloud generated from the mesh is in .laz format.

 

Note: This point cloud is expected to have a much bigger size than the point cloud files that are generated during the Densify step.

Export Point cloud from mesh .laz after selecting density and destination folder.

Mesh

 

Access: Once processed, the Mesh can be exported from the file menu (File>Export mesh...) or the processing panel (Exports>Mesh).

Export Mesh files from the processing panel Exports menu.

The following formats are available when exporting the Mesh:

• obj (default): PIX4Dmatic exports a Mesh obj that is not georeferenced. It has coordinates in a local coordinate system centered around the project. With some external viewers, it is possible to add an offset.xyz file to correctly position the Mesh. Once completed, the Mesh will have the same precision as the mesh viewed in PIX4Dmatic. The project_name_offset.xyz file contains the offset of the project and is stored in the folder with the .obj file.
• Cesium 3D Tiles: This format allows the Mesh to be easily shared and displayed across many third-party software and 3D platforms. The primary purpose of 3D Tiles is to improve the streaming and rendering performance of massive heterogeneous datasets. The foundation of 3D Tiles is a spatial data structure that enables Hierarchical Level of Detail (HLOD). When selecting and exporting the Cesium 3D Tiles a .json file and various .b3dm files are generated inside the folder project_name-cesium_mesh.
• slpk: A Scene Layer Package (SLPK) file is an openly published file format for 3D geospatial data, designed as a package for storage or exchange that captures all resources for a "scene layer" structured according to the Indexed 3D Scene Layer (I3S) specification. Mesh (LOD) can be exported as .slpk for ESRI compatibility. The SLPK Mesh file is geo-referenced, and the exported multi-LOD mesh in .slpk format is named project_name-mesh.slpk.

  

  
  Export Mesh after selecting format and destination folder.