This tutorial outlines the complete workflow for creating professional-grade output in PhotoMesh using close-range photos:
- Step 1: Creating a New PhotoMesh Project
- Step 2: Loading the Project Photos
- Step 3: Setting the Aerotriangulation Area
- Step 4: Performing an AT Only Build
- Step 5: Starting and Managing Fusers
- Step 6: Performing Full Build and Generating Outputs
Data Included in Training Folder (AirMap_CellTower)
This project’s photos and LiDAR were collected using a single Hasselblad L1D-20c camera, mounted on a DJI drone mount. This data is included in the AirMap_CellTower folder:
- Photos folder
- 1603 photo files
Step 1: Creating a New PhotoMesh Project
- Click Start > Skyline PhotoMesh > PhotoMesh.
- Click the PhotoMesh button, and then click New (CTRL+N). The New Project dialog box is displayed.
- Enter a name and path location for your project.
Step 2: Loading the Project Photos
Photos can be loaded into a project using several different methods. In this tutorial, we will be loading photos using the Load Folder option. All photo and photo collection information are included in the photos’ Exif information. More about: Loading Photos into a Project >
To load photos:
- On the PhotoMesh Home tab, from the Photos dropdown menu, select Load Folder.
- Browse to the Photos folder, and click Open.
Step 3: Setting the Aerotriangulation Area
The AT area defines the area of the project on which PhotoMesh should perform aerotriangulation. Aerotriangulation is the process for determining the correct position and orientation of each of the project photos, based on inputted photo information, ground control points and tie points. If a project’s photos do not have fully trusted camera positioning and orientation information, this process must be performed before generation of the 3D mesh model.
The AT area automatically defined by the photos' GPS tag includes all the project’s photos. If you want to restrict the AT area to only the photos within a specific area on the terrain, the specific area can be defined using an AT area polygon that you draw or import. This enables you to perform aerotriangulation on a small subset of the project to validate camera parameters and build settings and check the resulting AT and reconstruction tiles before building the full project. More about: Setting the AT Area >
This project includes only 1600 photos and is vertical, so the automatic AT area defined by the GPS tags can be used. Therefore, no action is required to set the AT area.
Step 4: Performing an AT Only Build
For optimal AT results, it is recommended to initially perform only the aerotriangulation step (“AT Only”), and then review the results, to ensure a precise AT which includes all project’s photos that intersect with the AT area, before proceeding with the rest of the build. If the results of the AT Only were in fact satisfactory, you can continue with the rest of the build process.
If the results of the initial AT Only build were unsatisfactory, AT parameters or collection properties should be modified and/or control points added/edited based on the aerotriangulation result, and then the AT should be repeated. More about: Evaluating and Improving Your AT >. When repeating the aerotriangulation, PhotoMesh determines precisely which tiles and which specific AT sub-processes were affected by the modification of properties or control points, enabling a much lighter and faster AT process. This iterative process should be repeated until satisfactory AT results are achieved.
To perform an AT Only build:
- On the Home tab, click Build. The Build Parameters dialog box is displayed.
- On the Steps tab, in the Build Steps section, select AT Only. Then in the Preset section, select Close Range Object. The bottom section of the dialog is automatically populated with the presets that will be applied to your project.
- Click Build. Then enter a build name and click Ok. The PhotoMesh Build Manager is displayed.
- Select the required fusers (see Step 5) and click Build.
Step 5: Starting and Managing Fusers
PhotoMesh fusers are the worker components of PhotoMesh, which allow you to share the demanding processing requirements of the different build steps (photo preparation, AT, point cloud, mesh model, texture, 3DML/other outputs) between several computers on the same network. When beginning the build process, the PhotoMesh Build Manager application determines what build steps are required and assigns them to the different fusers. PhotoMesh Build Manager and PhotoMesh fusers use the working folder to communicate: to deposit and collect pending tasks, and share information about fuser availability, status and progress. Before beginning the build process, you should start the fusers that will be participating in the build and set their working folder. More about: Working with Fusers >
Step 6: Performing a Full Build and Generating Outputs
After satisfactory AT results are achieved in an AT Only build, you are ready to perform the full build process and generate your required outputs.
To perform a full build:
- On the Home tab, in the Build group, click Build. The Build Parameters dialog box is displayed.
- On the Steps tab, select Complete Project.
- Click the Reconstruction tab to configure the reconstruction parameters. More about: Setting Build Parameters > The parameters should already be defined as required based on the presets selected in step 4. Set the Point Cloud Quality option to Low 1/4 resolution.
- On the Output tab of the Build Parameters dialog, select the 3DML check box. Then click Build. Enter a build name in the New build description dialog, and click Ok. More about: Setting Output Formats >
- When the build is complete, it will be listed in the Project Tree. Check its box to display the final output.
Note: To open the project in TerraExplorer, right-click on the build folder in the Project Tree and select Open with TerraExplorer.
See here for a case study demonstrating the use of PhotoMesh in generating a precise 3D model from oblique and close-range data.