After a 3D mesh model is created in Skyline PhotoMesh, certain tiles may require editing, e.g. to remove a particular building that is being torn down, remove the texture of a vehicle, or to flatten surfaces and correct certain imperfections such as floating components (e.g. electric lines, lamp poles), bumps or irregular surfaces. These imperfections can be edited in TerraExplorer using manual retouch layers, in which you mark surfaces for flattening and floating artifacts for removal. The implementation is then performed in PhotoMesh.
An SQLite retouch layer is first exported from PhotoMesh and loaded into TerraExplorer, where additional retouch markings are created by drawing or importing polygons and polylines. These markings are stored directly in the retouch layer. Once editing is complete, the same SQLite retouch layer is reimported into PhotoMesh and applied during project rebuild to constrain the reconstruction process.
The retouch layer contains polygonal features with attributes that define the required action for each marked area, such as clean, flatten, or retexture. During rebuild, PhotoMesh updates the 3D layer geometry accordingly and retextures the affected areas using the project’s photos, a selected color, or with a specified file based texture such as water or grass.
The visual reference used to define retouch areas can be either of the following:
- Mesh mode: A 3D model, either the reconstruction tile’s textured model or the final 3D layer
- Ortho mode: Orthophoto output
Opening the Tool
The Manual Retouch tool is opened from the Tools tab > Manual Retouch
Retouch Operations
The following retouch operations can be performed:
Mesh Mode
- Flatten Polygon – Remove all elements inside a defined volume, and add a flat surface in the area of the 2D polygon. For e.g., filling holes and flattening walls.
- Flatten Profile – Create multiple flatten polygons by defining a profile line (usually on a roof top) and the base elevation. A flatten polygon is created for each segment of the profile line (from the line to the base elevation). This method is useful for creating retouch polygons in hard to access places, e.g., between buildings.
- Remove Floating – Remove all elements inside a defined volume. This option is generally used to remove floating elements that aren’t connected to the ground.
- Remove Wire – Remove thin elements such as power lines by drawing a polyline that marks the wire to be removed. A separate floating polygon is created for each segment of the polyline.
- Water Polygon - Detects and flattens water surfaces by analyzing texture colors within the drawn polygon.
Ortho Mode
- Clean Cars – Remove all elements inside a defined area, and texture the drawn polygon area using only photos from the area that don’t include moving cars. This option offers a solution to undesirable effects in the reconstruction (e.g., a car that is partially sunk in the road) that can occur when capturing an area with moving cars, since only some of the captured photos included the cars, while others did not. It is recommended to individually retouch each car you want to remove by applying a unique polygon to it.
- Clean Edges – Remove artifacts along the edges of a model.
- Import Layer – Import a polyline or polygon feature layer with retouch polylines/polygons for cleaning edges or cars. The following layer formats are supported: .shp, sqlite, and gpkg.
After drawing the retouch polygon or polyline, it can be extruded upwards or frontwards and downwards or backwards using Front buffer and Back buffer sliders.
Display Options
Retouch polygons can be displayed in any of the following ways:
- Volume Colorize – Mark the area for retouching by colorizing all parts of the mesh contained within the extruded polygon.
- Volume Polygon – Mark the area for retouching by displaying 3D polygons based on the extruded polygon.
- Volume No – Mark the area for retouching only with a 2D polygon.
Drawing Surface
Drawing surfaces 
can be used to create a surface on which to draw your retouch polygon or polyline, e.g., for a model that is not flat or missing corners. The following options are available:
- Horizontal – The surface is aligned horizontally to the area under the cursor.
- Vertical – The surface is aligned vertically to the area under the cursor.
- 3 Points – The surface is aligned to the polygon created by the three points you draw.
More about: Retouching a mesh layer in TerraExplorer >