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 cleaned up directly in PhotoMesh using the Manual Retouch tool or in external software.
In this article:
PhotoMesh's Manual Retouch Tool
This tool performs smart selection, taking your rough marking of floating artifacts, wires, or surfaces for flattening, analyzing the pixels, and determining the object it thinks you want within the rough selection. You can then further modify the selection polygon and adjust the applied buffers. The output of the Manual Retouch tool is a polygonal feature layer with attribute information that defines what retouch action should be performed in each area: clean, flatten, and retexture. When rebuilding the project, PhotoMesh uses the manual retouch layer to add a set of constraints to the reconstruction algorithms. Most of the constraints defined apply to the mesh model, and the modified model is then retextured using the project’s photos. There is also an option in the Manual Retouch tool to set a specific file texture, e.g., water or grass, for a marked area, instead of basing texturing on the project’s photos.
You can run the manual retouch tool either on a 3D model (the reconstruction tile’s 3D textured model or the final 3DML) or on orthophoto output. All retouch operations are listed in the Manual Retouch list.
After performing manual retouch operations, all affected tiles (e.g., tiles that now are intersected by the manual retouch polygon) require rebuilding from the point cloud step. PhotoMesh will automatically determine what processing is required following the change, by rebuilding the project from “Auto”.
Opening the Tool
The Manual Retouch tool is opened from the Home tab > Retouch > Open Manual Retouch Toolbox.
You can run the manual retouch tool either in mesh mode - on a 3D mesh model (the reconstruction tile’s 3D textured model or the final 3DML) or in ortho mode - on orthophoto output.
The following retouch operations can be performed in mesh mode:
- Flatten Polygon (Shortcut key: f) – 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. The area of the 2D polygon can be textured with any of the following:
- From photos – Fill the polygon area using photos from the area.
- Remove moving cars – Fill the polygon area using only photos from the area that don’t include moving cars. This option offers a solution to undesirable reconstruction effects that can occur when capturing an area with moving cars (e.g., a car that is partially sunk in the road), since only some of the captured photos included the cars, while others did not.
- Single color – Fill the polygon area using a single color.
- Texture pattern – Fill the polygon area with a water or grass texture.
- Flatten Profile (Shortcut key: p) – 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 (Shortcut key: r) – 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 (Shortcut key: w) – 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.
The following retouch operations can be performed in orthophoto mode:
- Clean Cars (Shortcut key: c) – 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.
- Clean Edges (Shortcut key: e) – Remove artifacts along the edges of a model.
- Import Layer (Shortcut key: i) – 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.
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.
In mesh mode, 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 PhotoMesh >
Manual Retouch in External Software
Mesh geometry and texture edits can also be performed in external software such as Autodesk® MeshMixer, Blender, and others, and then the tiles can be imported back into PhotoMesh in order to rebuild the project.
For the full PhotoMesh – Editing Mesh Geometry and Texture manual, click here.