Agisoft Metashape: Video Photo Cutting and 3D Model Building

(Recommended to save the project after each step)

1. Cutting Photos from Video

• Go to File > Import > Video. • Choose a folder to save the extracted images. • Trim the video to remove unnecessary parts by setting Cut In and Cut Out. • Set Frame Step to Large.

2. Align the Photos (This step also call Tie Points)

• Go to Workflow > Add Folder > Single > Add Photos. • Next, go to Workflow > Align Photos. (Accuracy: Moderate) Once the processing is complete, click the Camera Icon to proceed.

3. Move Region

* organize the box on the model area.

4. Scale the Model

• Add marker point > Right click on a specific point and 1 more point.

• Create scale bar > Select 2 point in the reference > Right click on the scale bar > modify- change the distance.

• Model > Transform Object > Update Transform

5. Cleaning

Manual cleaning – go to manual selection icon and select “free form”, then select the point that irrelevant and delete.

6. Building the Point Cloud

• Go to Workflow > Build Point Cloud

Quality: Medium Click- save project after each step Click- Calculate point confidence Depth filtering: Mild

(After this stage you can skip to stage 9 and build DEM- if you don’t need a nice 3D model)

7. Building the 3D Model (The “Build Model” - creating a 3D representation of your object, which includes both dense cloud generation and mesh creation)

• Go to Workflow > Build Model.

• Source data: Point cloud.
• Face count: Moderate.

After the processing is complete, click the Triangular Icon to finalize the model.

8. Building the Texture (the Build Texture process is used to apply photographic textures to a 3D mesh or model, giving it realistic surface details. Essentially, it wraps your 3D model in high-resolution imagery to make it look more lifelike and visually accurate)

• Go to Workflow > Build Texture.

- Texture type: Diffuse map
- Source data: images
- Mapping mode: Generic
- Blending mode: mosaic
- Texture size: 8192

After the processing is complete, click the small arrow next to the Triangular Icon and select TEXTURED.

9. Building the DEM (Digital Elevation Model - represents the elevation of the terrain. It is created from the dense point cloud or mesh)

• Go to Workflow > Build DEM.

10. Building the Orthomosaic (is a type of aerial photograph that has been geometrically corrected so that the scale of the image is uniform across the entire image. In simpler terms, it’s a map-like image where the distortions from the camera angle or topography have been removed, making it a “true” representation of the earth’s surface)

• Go to Workflow > Build Orthomosaic.

• Set Pixel Size to 0.0005x 0.0005y.

11. Exporting Results

• Go to File > Export > Export Orthomosaic.
• Choose JPEG (with Tiff: None). • Export DEM:
• Go to File > Export > Export DEM.
• Choose Tiff.

ArcGIS analyze DEM for rugosity

ADD data🡪 import DEM file

Catalog🡪 System Toolboxes🡪Spatial Analyst Tool 🡪 Neighborhood 🡪 Focal Statistics

Focal Statistics: Import raster- DEM file (Do this step 3 time for: Min, Max and Mean) (Mukherjee et al 2020)

Catalog🡪 System Toolboxes🡪Spatial Analyst Tool🡪Map Algebra🡪Raster Calculator

Raster Calculator: (mean-min)/(max-min)

Right click on TRI Layer 🡪 Symbology 🡪 Classifed 🡪 Export as Raster

Catalog🡪Raster to polygon: import the raster

OR Raster to point