Vectorization - PIX4Dsurvey

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PIX4Dsurvey allows one to vectorize point clouds made with PIX4Dmapper, PIX4Dmatic, laser scanners, LiDAR, or other third-party tools and assign the objects to layers. You can precisely define the position of the geometry by using original images or the vertex editor. 

GIF animation of vectorization of point clouds in Pix4Dsuvey, catenary and building

Selection tools in PIX4Dsurvey

The following selection tools are available in PIX4Dsurvey:

  • Pix4Dsurvey_select_tool_icon.png Simple selection (default)
  • Pix4Dsurvey_rectangular_selection.png Rectangular selection
  • PIX4Dsurvey_polygon_selection_icon.png Polygon selection
  • PIX4Dmatic_color_selection_icon.png Color selection
  • road_selection-16.png Road selection

Vectorization tools in PIX4Dsurvey

The following vectorization tools are available in PIX4Dsurvey:

  • Pix4Dsurvey_polyline_icon.png Polyline
  • Pix4Dsurvey_marker_icon.png Marker
  • Pix4Dsurvey_polygon_icon.png Polygon
  • circle.png Circle
  • Pix4Dsurvey_catenary_icon.png Catenary
  • roadmark_detection.png Assisted road marking
  • assisted_curb_detection.png Assisted curb detection (Beta)

How to use selection and vectorization tools in PIX4Dsurvey

Selection tools specifics:

  • Simple selection (default): Click on the object to select it. Right-click on the object to use Move to layer or Delete geometry options. 
  • Rectangular selection: Hold Ctrl or to freeze the screen and select the points in the point cloud, points in the Grid of Points, vector layers, or all objects in the selected area.

    PIX4Dsurvey_Vector_region_select.gif

    Hold Ctrl or ⌘ and draw the selection.

  • Polygon selection: Select the points in the point cloud, points in the Grid of Points, vector layers, or all objects in the selected area.
  • Color selection: Select points based on color, tolerance, and radius.
  • Road selection: Select points based on color, tolerance, elevation, and spatial continuity.

Vectorization tools specifics:

    • Polyline: Minimum of two points need to be clicked in the 3D view to define a polyline.
    • Marker: Click on a point in the 3D view to create a marker.
    • Polygon: Minimum of three points need to be clicked in the 3D view to define a polygon.
    • Circle: The first vertex defines the center of the circle, and the second vertex defines a point at the circumference. Circle objects are always horizontal, and the elevation is defined by the point of the point cloud selected for the center. The second point must also be on the point cloud, but the circle will be drawn at the altitude of the center defined by the first point.
    • Catenary: For vectorization of freely hanging power lines, chains and ropes. Minimum three points need to be clicked in the 3D view.
    • Assisted road marking: Click on two points on the line to automatically vectorize it. For more: Assisted road marking.
    • Assisted curb detection: Click on two points on the curb to automatically vectorize it. For more: Assisted curb detection.
Tip: When vectorizing catenaries, the order of the clicks is not important. The mathematical line that represents the catenary curve will be calculated based on all clicked points.
Tip: Polygons can be converted into polylines (right click > convert to polyline).
Circle objects can be converted into polygons or polyline (right click > convert to polygon/polyline).

To use the selection and vectorization tools:

  1. Select the tool on the toolbar.
  2. Left-click on the point cloud in the 3D view to create the first vertex and to start the vectorization.
  3. Continue using the left-click to add more vertices to the geometry.
  4. (Optional) Press the Esc key to cancel the vectorization. 
  5. To finish the geometry:
      • Right-click in the 3D view to add the last vertex and to finish the geometry.
      • Alternatively, press Enter to accept the edits and to finish the geometry.
  6. (Optional) Right-click again to exit the vectorization tool and to change to Pix4Dsurvey_select_tool_icon.png Simple selection (default).
 
Note: When pressing Enter the current state of the geometry will be accepted and no additional vertices will be added. To speed up the vectorization, we recommend using the right-click as it adds the last vertex as well as finishes the geometry.

Export vector layers

The vector layers that need to be exported can be filtered to match your requirements. It is possible to select specific layers [1] and/or filter by object type [2].

The vector layers can be exported in .dxf, .zip shp, .shp, GeoJSON, and .csv (only for makers) formats [3].

Vector Layers Export - PIX4Dsurvey

Vector layers export panel in the Export sidebar.

If the .csv format is selected (comma-separated values), only markers will be exported. The format of the resulting table can be selected.  

Format Meaning
PENZD Point name, Easting coordinate, Northing coordinate, Z coordinate, Description
PXYZD Point name, X coordinate, Y coordinate, Z coordinate, Description
PENZ Point name, Easting coordinate, Northing coordinate, Z coordinate
PXYZ Point name, X coordinate, Y coordinate, Z coordinate
ENZ Easting coordinate, Northing coordinate, Z coordinate
XYZ X coordinate, Y coordinate, Z coordinate
 
Tip: If you want to export markers to use them in PIX4Dcloud or PIX4Dcloud Advanced, use the PXYZ Column format and uncheck the Include column headers checkbox.

Additional information about the export tool can be found in the Export - PIX4Dsurvey page article.

Measuring vectors

Lenght, elevation, area, slope, and location are measured for vectorized geometries. The list below shows which features are measured for each geometry type.

  • Polyline
    • 3D length [m, ft]: The length of the polyline in the 3D space.
    • Min elevation [m, ft]: The minimum elevation of the polyline.
    • Max elevation [m, ft]: The maximum elevation of the polyline.
    • Min slope [° or %]: The minimum slope of the polyline.
    • Max slope [° or %]: The maximum slope of the polyline.
  • Polygon
    • 3D perimeter [m, ft]: The length of the perimeter of the polygon
    • 3D area [m2, ft2]: The 3D area of the polygon.
    • Min elevation [m, ft]: The minimum elevation of the polygon.
    • Max elevation [m, ft]: The maximum elevation of the polygon.
  • Marker
    • Easting [m, ft]: The easting coordinate of the marker.
    • Northing [m, ft]: The northing coordinate of the marker.
    • Altitude [m, ft]: The elevation of the marker in the case of a geoidal vertical coordinate system or
    • Ellipsoidal height [m, ft]: The elevation of the marker in case of an ellipsoidal vertical coordinate system.
  • Circle
    • Radius [m, ft]: The radius of the circle.
    • 2D area [m2, ft2]: The 2D area of the circle.
    • Elevation [m, ft]: Elevation of the circle, defined by its center.
  • Catenary
    • 3D length [m, ft]: The length of the catenary in the 3D space.
    • Min elevation [m, ft]: The minimum elevation of the catenary.
    • Max elevation [m, ft]: The maximum elevation of the catenary.
  • Assisted road marking
    • (see polyline)
  • Assisted curb detection
    • (see polyline)
Note: The unit of the slope can be switched between degrees [°] and percentage [%]. Select a polyline and use the toggle button appearing in the polyline description under the Measurement section. The value is expressed with a single decimal place.

Editing geometry in the 3D view

To move the vertex in the 3D view

  1. Use the Simple selection tool to select an object.
  2. Click on the existing geometry.
  3. Click on the vertex and drag it to the new position.
     
    Tip: To speed up the editing, move to the next vertex using the Tab shortcut.

After moving the vertex to the new position, the edits are automatically taken into account and you can continue creating new geometries or edit existing ones. 

To add a vertex to existing geometry

  1. Use the Simple selection tool to select an object.
  2. Hover over the section where you would like to add the vertex.
  3. Click to create a new vertex.

To remove a vertex from existing geometry

  1. Use the Simple selection tool to select an object.
  2. Click on the existing geometry.
  3. Click on the vertex and press the Delete key.

To split the polyline

  1. Use the Simple selection tool to select an object.
  2. Right-click on the vertex where you would like to split the polyline.
  3. Click Split polyline.

After the polyline is split, two separate polylines are created. The polylines share the vertex in which they were split.

To join polylines

  1. Use the Simple selection tool to select the first polyline.
  2. Hold Shift and select the second polyline.
  3. Right-click on the shared vertex and click Join polylines.

After the polylines merged, a single polyline is created.

 
Important: The Join polylines feature is available only when two polylines share a vertex.

Editing geometry on images

 
Important: Only available for perspective cameras' projects processed in PIX4Dmapper or PIX4Dmatic. For more information see How to import a PIX4Dmapper project into PIX4Dsurvey or How to import a PIX4Dmatic project into PIXDsurvey articles.

To move the vertex on the images:

  1. Use the Simple selection tool to click on an object.
  2. Click on the vertex on the image and drag it to the new position on at least two images.
  3. Press Enter to accept the edits.
    Tip: To speed up the vectorization, accept the edits by simply clicking in the 3D view or moving to the next vertex using the Tab shortcut.
  4. (Optional) Hit the Esc key to cancel the edit.

After moving the vertex to the new position on at least two images, the position of the vertex is automatically changed and updated.

Note: Vertices must be marked on at least two images. For more accurate results, it is recommended to mark the same vertex in three or more images.

Editing geometry with vertex editor

It is possible to manually adjust the coordinates of created vertices.

Vertex editor interface

Vertex editor interface allows modifying the X, Y, and Z coordinates for each vertex.

To move the vertex using the vertex editor:

  1. Use the Simple selection tool to select an object.
  2. Click on the vertex, the center will become purple. The dialog Coordinates opens in the bottom left corner of the screen.
  3. Edit the coordinate values by:
    • Typing the new coordinate values.
    • Adjust the coordinate values with the +/- button or by typing the new value.
  4. Click the Ctrl+Enter keys to accept the edits.
    Tip: To speed up the vectorization, accept the edits by simply clicking in the 3D view.
  5. (Optional) Hit the Esc key to cancel the edit.

Editing geometry with vertex alignment

In the case of objects with more than 1 vertex (polylines, polygons, volume polygons), it is possible to align the vertices to a specific altitude.

Vertex alignment interface

Align vertices button vertex_align.png and interface, allowing to vertically align all the vertices of the same object to the same height.

To vertically align the vertices: 

  1. Use the Simple selection tool to select an object.
  2. To access the vertical alignment menu, select the vector object, click Align Vertices vertex_align.png located near the object name in the bottom left corner of the PIX4Dsurvey window and choose the desired alignment:
    • vertex_align_high.png Vertex alignment high: All the vertices of the selected object are moved vertically to align with the highest vertex.
    • vertex_align_center.png Vertex alignment average: All the vertices of the selected object are moved vertically to align with the average altitude of all vertices of the selected object.
    • vertex_align_low.png Vertex alignment low: All the vertices of the selected object are moved vertically to align with the lowest vertex.
    • Custom height: All the vertices of the selected object are moved vertically to align with the given custom height.

 

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7 comments

  • Aaron Meyer

    I like the simplicity of adding geometry.  I'm testing it on the example dataset.  Is there a way to delete a vertex without deleting the geometry?

  • Avatar
    Blaž (Pix4D)

    Hi Aaron, great to hear you are trying out Pix4Dsurvey.

    To delete an individual vertex you can:

    • Use the Select tool to click on an object.
    • Click on the existing geometry.
    • Click on the vertex and press the Delete key.

    Best,

     

    Edited by Blaž (Pix4D)
  • Midwestern Consulting

    I am really enjoying this product.  Is there a way to create an arc on pavement areas and curbs?

  • Avatar
    Blaž (Pix4D)

    Hi, 

    At the moment, the tool that would create an arc based on a few clicked points is not implemented in Pix4Dsurvey. But the idea is interesting, and we will consider it for future releases. 

    Feel free to also check the Pix4Dsurvey Feature request post to add more suggestions. 

    Best,

  • Manuel del valle

    Hola,

    Como logro realizar que mi polígono abarque la superficie seleccionada y no sea solo en 2d.

    Saludos.

  • Avatar
    Blaž (Pix4D)

    Hi Manuel, 

    The polyline is defined by the 3D vertices that you click on the model. The polyline will connect the defined vertices but will not exactly follow the terrain as in the case of cross-sections. 

    Could you tell me more about why would you find it beneficial for the polyline to follow the terrain?

    Best,

  • Manuel del valle

    Hola Blaz,

    Gracias por contestar.

    Me resultara beneficioso ya que obtendría la superficie dentro del polígono, para comparar superficies de vuelos semanales  y obtener volúmenes entre superficies.

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