Point clouds

Tekla Structures
2021
Tekla Structures

Point clouds

Point clouds are groups of measured points on the surfaces of objects created with 3D laser scanners, for example, Trimble 3D laser scanners. In construction, the point clouds are mainly used in renovation projects to define the building or structure that is to be renovated. They can also be used to get the exact position of existing machinery, pipework or landscape that need to be taken into consideration on the site. You can also use them to check execution by importing them as build points into a model to be compared to the design.

About point clouds in Tekla Structures

  • When you attach a point cloud to a Tekla Structures model, you can place it either by the model origin or a defined base point.

  • The original point cloud file is processed and cache files are created in the Potree format. The point cloud conversion occurs as a background process, and you can continue working with Tekla Structures meanwhile.

  • Point cloud data is stored in the folder defined by the advanced option XS_POINT_CLOUD_CACHE_FOLDER. By default, the folder is %LocalAppData%\Trimble\Tekla Structures\PointClouds, for example, C:\Users\<user>\AppData\Local\Trimble\Tekla Structures\PointClouds. The XS_POINT_CLOUD_CACHE_FOLDER advanced option is user-specific, and it is located in the File Locations category in the Advanced Options dialog box.

  • If the point cloud file is in the Potree format already, then the original file is used without any conversion or copying to the ..\Pointclouds folder.

  • If the same point cloud is used in several models, it will not be converted again or duplicated when you attach it. If point clouds are identical, the existing converted file is used, otherwise the file is converted.

  • It may be useful to use a network drive for the potree file in a project. The file will not be copied to the local computer.

  • You can also use point clouds through internet. Point cloud web streaming cache is a common cache with Trimble Connect for Windows. You can define the cache folder using the advanced option XS_POINT_CLOUDS_WEB_CACHE in the File Locations category in the Advanced Options dialog box. By default, the folder is %LocalAppData%\Trimble\Trimble Connect\Import, for example, C:\Users\<user>\AppData\Local\Trimble\Trimble Connect\Import. The cache usage improves the performance of the web streamed point clouds.

  • In Tekla Structures, point clouds have colors if the original file format supports colors.

  • Point clouds can be seen in both the OpenGL model view and in the DX model view. The DX model view with perspective projection may give better visual result. Performance with bigger amount of data and/or larger number of views may make DX usage impossible.

Compatible file formats

ASCII (.asc, .xyz)

E57 (.e57)

LAS (.las)

LAZ (.laz)

PTS (.pts)

PTX (.ptx)

Potree (.js)

Trimble scan format (.tzf)

Limitations

  • Some basic Tekla Structures model handling functionalities are not available, such as select, undo, move, rotate, copy, and pop-up menu on right-click.
  • Point clouds are not autosaved.
  • You cannot delete a point cloud from the point clouds list using the keyboard button Delete.
  • Point clouds are not visible in drawings.
  • Point clouds are not shared in Tekla Model Sharing or in multi-user mode.
  • For the file formats ASCII, PTS: On each text line, the first three fields must be: x y z. For colored point data, the last three fields must be: r g b

Attach a point cloud to the model

  1. Click the Point clouds button in the side pane.
  2. If you want to place the point cloud inside the work area, select the Show inside work area only check box.
  3. Click Attach.
  4. Browse for the point cloud file, or enter the URL address of the point cloud.

    Note that when you are using a URL, you need to create the HTTP directory structure potree that you can create with Point Cloud Manager.

  5. Change the point cloud scale, if needed.
  6. In Location by, select Model origin to place the point cloud in the model origin, or select a base point to place the point cloud in the real world coordinates.
    Note: If you do not know the coordinate system of the point cloud, select Auto-created base point to get the point cloud near the model origin. Automatic base point with point cloud bounding box min x, min y, and min z coordinates will be created in Tekla Structures origin.
  7. Click Attach point cloud.
  8. To show the point cloud in the model, select the model view where you want to show it, and click the eye button next to the point cloud in the list.

    Note that when you select a model view, it has a yellow frame.

    When the point cloud is set visible in the model view, you can see the min x, min y, and min z coordinates of the point cloud bounding box on the status bar.

    To hide the point cloud, click .

When you are modeling, you can snap to points for modeling and measuring distances. You can use clip planes in point clouds to exactly show what you want, for example, clip off the roof and some of the floors so that you can see the bottom floor of the building, and everything there that needs your attention in the planning phase. You can also use the Clipper tool in Tekla Warehouse for handling several clip planes at a time, and split the model to smaller pieces for visualization and modeling.

Modify point cloud properties and visualization settings

You can modify the point cloud properties and visualization settings when you have attached a point cloud, and DirectX rendering is active.

Note that the point cloud Visualization settings are view specific and settings are enabled for one view only, the name of which can be seen at the top of the Point clouds side pane (if you have not selected multiple views). The Properties settings are enabled only if the point cloud is selected from the list.

  1. When you have attached the point cloud, select it from the point clouds list in the side pane.
  2. Adjust the point cloud location, scale and rotation. To modify the values, you need to select the point cloud in the side pane.

    Use the Reset button to return the values that we saved for the point cloud the last time.

  3. Click Modify.
  4. In Visualization settings, use the EDL (Eye-dome lighting) effect to improve the depth perception of the point cloud. Drag the sliders to increase or decrease the outline thickness and strength of the point cloud. You can deactivate the EDL effect by clicking the EDL button.

  5. In Visualization settings, adjust the size and density of the points by dragging the sliders.
  6. In Visualization settings, change the point cloud colors. Normally, the default color values are in use. The visualization settings are view specific and therefore you can use different settings in different views.
    • You can color the point cloud by elevation by dragging the sliders.

    • If the point cloud contains classifications, you can change the color of the classification category points or hide them.

    • Check clashes and deviations by using different colors for different tolerances. You can detect points that are inside or within a distance from the selected parts and selected reference model objects based on the settings you define.

      Note that rendered objects coloring may cause confusing results. It is recommended to use Ctrl+1 and Shift+1 visibility modes to get unambiguous results.

  7. Save the properties and visualization settings for future needs.

Detach a point cloud from a model

  • To detach a point cloud, click Detach next to the point cloud name in the Point clouds list. Then reopen the model or save the model.

    Note that you cannot detach the point cloud by pressing Delete on the keyboard.

    The point clouds are cached to the default location or to the location specified by the user. When a point cloud is no longer used in any Tekla Structures model, it is cleaned from cache.

Set the default maximum point count in a view

You can use the advanced option XS_SET_MAX_POINT_CLOUD_POINT_COUNT to set the default maximum value for the points in a view. The default value is 10 000 000 (10 million).

This advanced option is system specific, and it is located in the Model View category of the Advanced Options dialog box. Restart Tekla Structures if you change the value.

Clip point clouds and reference models only

Set the user-specific advanced option XS_DO_NOT_CLIP_NATIVE_OBJECTS_WITH_CLIP_PLANE to TRUE to only clip point clouds and reference models with the Clip plane command. Native Tekla Structures objects are not clipped. FALSE is the default value. This advanced option is located in the Model View category in the Advanced Options dialog box.

Redraw the model views after changing the value.

Point cloud example

In the first image below, a point cloud has been attached to a model in a plan view. Remember to select a model view and click the eye button , otherwise the point cloud will not be shown.

In the next image, the clip plane tool has been used to cut off floors and other structures:

In the next image, a section has been cut to be used in a section view:

The last image shows the section view:

Share point clouds with other users

Point clouds are normally so large in file size that it is not sensible to share the point cloud as a part of the model data. Point cloud is not structural domain data but project data that is not a part of the model, and therefore it is not dependent on the model save. However, there is need for multiple persons to use the same point cloud model efficiently. You can use the potree file for sharing the point cloud. The best practices in sharing the point cloud potree file among model users are explained below. You first need to create the potree file and copy the potree file to a shared location, and then other users can attach it to their Tekla Structures model.

Create a potree file

Option 1: With Tekla Structures

  1. Create a potree file by attaching a point cloud model to a Tekla Structures model.

    The potree file is created to the folder defined by the advanced option XS_POINT_CLOUD_CACHE_FOLDER. The potree file is named as <potree_name>.db, and it has a folder with the same name. For example:

  2. Copy both the <potree_name>.db file and the related folder to a shared location. You can rename the model if you want, in which case you also need to rename the folder.

    Note:

    Do not replace existing potree data, especially if it is used by other users.

Option 2: With Point cloud manager

You can download Point cloud manager from Tekla Warehouse.

For detailed instructions about using Point cloud manager, see the Point cloud manager help. You can open the help by clicking the help button .

To use the Point cloud manager:

  1. Install the application, and start it from the start menu or start screen, depending on your Windows version.

  2. Set the root folder for the project, for example C:\Trimble\PTRS.

  3. Click the Add new project button to create a project with a given name.

    This name will be the name of the potree database and potree folder.

  4. Import one or more point cloud models by clicking Add file, and browsing for the point cloud file.

  5. When the point cloud has been imported, create the potree by clicking .

  6. Copy the <potree_name>.db and the <potree_name> folder to a shared location. Attaching a potree requires both the <potree_name>.db and the <potree_name> folder.

Note:

Do not replace existing potree data, especially if it is used by other users.

Attach a potree from a shared location

  1. Open Tekla Structures and the Point clouds pane from the side pane.

  2. Browse to the point cloud folder (mypotree in the example above) and select the point cloud .js file. Then follow the instructions above for attaching the point cloud.

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