This tutorial outlines the complete workflow for creating professional grade 3D output in PhotoMesh using drone data, from loading your photos into PhotoMesh to generating 3DML output:
- Step 1: Starting a New PhotoMesh Project
- Step 2: Loading the Project Photos and Setting AT/Reconstruction Areas
- Step 3: Performing an AT Only Build
- Step 4: Starting and Managing Fusers
- Step 5: Performing a Complete Build
Data Included in Training Folder (Airwise_Sample_Drone_Data)
This project’s photos are included in the Airwise_Sample_Drone_Data folder:
- Nadir_Oblique_Images folder that has two subfolders:
- 45 folder, containing 141 jpg files. These are the oblique images.
- 90 folder, containing 144 jpg files. These are the nadir images.
Step 1: Starting a New PhotoMesh Project
Do the following:
- Click Start > Skyline PhotoMesh > PhotoMesh.
- Click File, and then click New (CTRL+N). The New Project dialog box is displayed.
- Enter a name and path location for your project. The Add Photos Wizard is displayed.
Step 2: Loading the Project Photos and Setting AT/Reconstruction Areas
Photos can be loaded into a project using several different methods. In this tutorial, we will be loading a folder of photos. More about: Loading Photos into a Project >
- In the Add Photos Wizard, select Load Photo Folder. Then browse to .\Airwise_Sample_Drone_Data\Nadir_Oblique_Images, and click Select Folder. This folder includes two subfolders: ‘45’ and ‘90’. A dialog box is displayed asking whether you want to create a separate collection for each folder. Click Yes. Once the photos are imported, click Next.
- The photo collections’ basic properties are displayed in the Add Photos Wizard. In the Coordinate System field of the first collection, click Select to set a different coordinate system. The Coordinate System dialog box is displayed.
- Search for "4326", and then select WGS 84 as the new coordinate system, and click OK.
- In the Add Photos Wizard, click Apply to all next to the first collection's coordinate system to apply the property value set for that collection to all loaded collections
- Set the reconstruction area to the same as the AT area: On the Home tab, in the Area group, from the Reconstruction Area drop-down menu, select Same as AT Area.
Step 3: 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. More about: Evaluating and Improving Your AT > Then the aerotriangulation should be repeated by selecting AT Only, and your results reviewed. 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, in the Build group, click Build. The Build Parameters dialog box is displayed.
- On the Build Settings tab, under Stages, select AT Only.
- Under Collection Type, select Nadir & Oblique since both nadir and oblique photo collections were added. The selected Collection Type determines what project presets are set to achieve optimum output for the project’s data.
- Then click the Presets tab, and click Select and Manage. The Preset Manager is displayed.
- On the Select Presets tab, clear the Selected Presets list on the right side of the Preset Manager by selecting each preset and clicking Remove. On the left side of the Preset Manager is a list of available presets. Select the AT: More aggressive match preset from the Available Presets list, and click Add to move it to the Selected Presets. Then click OK. This preset provides more aggressive matching for cases with a large variance of camera angles in a single collection.
- In the Build Parameters dialog, on the Aerotriangulation tab, note the settings that are defined by default for performing aerotriangulation. Click Build to start the build. The New build description dialog box is displayed.
- Enter a build name and click Ok. The PhotoMesh Build Manager is displayed.
- Enable the required fusers (see Step 4), and click Build.
Step 4: 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 5: Performing a Complete Build
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 build your project:
- On the Home tab, in the Process group, click Build. The Build Parameters dialog box is displayed.
- On the Build Settings tab, click Complete Project. This sets the project to resume building from the current step until completing the generation of the selected outputs.
- Select the check boxes of the required outputs. For the purposes of this tutorial, select 3DML.
- Click the Aerotriangulation tab to configure the aerotriangulation parameters. Most of the required aerotriangulation parameters were already defined based on the preset selected in Step 4. Set the following settings:
- Horizontal accuracy factor – Standard 0.1
- Vertical accuracy factor – Low 0.0001
- Calculate camera parameters – Per Photo (this is better for rolling shutter).
- Click the Reconstruction tab to configure the reconstruction parameters. The only parameter that requires modification is Point Cloud Quality. Under Quality & Performance, set the Photo Sampling Interval to Optimize. More about: Setting Build Parameters >
- Click Build. See Step 4 for information on starting and managing fusers.
- When the build is complete, it will be listed in the Build Outputs list. Select its Visible checkbox to display the final output.
Note: To open an output in TerraExplorer, in the Build Outputs list, click Open with TerraExplorer . A FLY file opens in TerraExplorer with the 3DML, AT Calculated Photos, AT Tiles, DSM, DTM, and Orthophoto outputs, if they were generated in the PhotoMesh project.