About-Working-With-Point-Clouds

About Working With Point Clouds

    About Working With Point Clouds

    A point cloud is a large collection of points placed on a three-dimensional coordinate
    system. Collected by 3D laser scanners or other technologies, millions of points create
    3D representations of existing structures.

    Point cloud files support the design process by providing real-world context where
    you can recreate the referenced objects or insert additional models. Once a point
    cloud is attached to a drawing, you can use it as a VCadeline for drawing, change
    its display, or apply a color stylization to distinguish different features.

    Using Autodesk® ReCap to Create and Segment Point Clouds From Scan Files

    Point clouds are derived from raw data gathered by using a 3D scanner to obtain points
    from such things as buildings, topographies, or manufactured items. Before you can
    use the data, it needs to be converted to readable point cloud files. Use ReCap to
    convert raw scan data to scan files (RCS files), and to create project files (RCP
    files) that reference multiple RCS files. Both these formats can be attached to an
    AutoCAD drawing.

    ReCap also segments data, which is a process of identifying groups of points in a
    point cloud that represent different surfaces. AutoCAD identifies these segments and
    extracts geometry 2D from the point cloud.

    Attaching a Point Cloud to a Drawing

    Attaching an RCS or RCP file to a drawing is much like attaching any other external
    reference (xref). If the unit of measurement in the attached point cloud differs from
    the units in the target drawing, the point cloud is automatically scaled based on
    the unit type in the target drawing.

    NOTE:Point clouds are not supported on 32-bit systems. To work with point clouds, you need
    a 64-bit system, and hardware acceleration must be turned on.

    Visualizing Point Clouds

    Change display settings to simplify the display and improve performance. Apply color
    stylizations to visually represent the data you’re interested in.

    • Modify point cloud density and point size. Manage program performance and visual noise by increasing or decreasing the number
      of visible points, as well as point size.

    • Use color stylization. Color stylization helps you analyze features within the point cloud. You can retain
      the original scan colors or stylize the point cloud based on object color, normals
      (point orientation), intensity, elevation, or LAS classification data.

    Cropping Point Clouds

    Crop rectangular, polygonal, or circular areas to show only the most relevant parts
    of the point cloud.

    Extracting Geometry from Point Clouds

    There are several types of geometry you can extract from a segmented point cloud.

    • You can extract the line marking the edge between two detected planar segments in
      a point cloud.

    • You can mark the point of the intersection between three detected planar segments
      in a point cloud.

    • You can extract the centerline of a detected cylindrical segment in a point cloud.
    • You can section a point cloud and extract 2D geometry from the objects within the
      section line.

    Extract 2D Geometry from a Sectioned Point Cloud

    Sectioning a point cloud allows you to extract the geometry from it. The PCEXTRACTSECTION
    command identifies the underlying 2D geometry in the point cloud and creates a 2D
    line drawing. By default, the geometry is created on a plane coincident with the section
    plane.

    You can define the which part of the geometry you want to extract, the layer it is
    created on, the color of the 2D lines or polylines, the width of the polylines, and
    adjust tolerance settings.

    Standard Editing Operations for Point Clouds

    • You can cut, copy, paste, move, scale, rotate, and erase point clouds.
    • You can change general properties such as color and layer in the Properties palette.
      Also: Modify the insertion point, rotation, and scale; lock and unlock the point cloud;
      show or hide cropped areas; and choose a color stylization and color scheme.
    NOTE:The MIRROR3D command copies and moves a point cloud, but does not mirror it. You cannot
    explode a point cloud.

    Navigating Point Clouds

    Several tools are available for navigating around point clouds.

    • Use the Point Cloud Manager to reveal or hide separate regions (RCS files) within
      a point cloud project (RCP file). Double-click a scan in the Point Cloud Manager to
      view the point cloud from the vantage point of the camera location for the scan. Use
      the 3DSWIVEL or 3DWALK commands to look around.
    • Use the 3DORBIT command in conjunction with the ORBITAUTOTARGET system variable to
      set a target point when orbiting about a point cloud.
    • The 3DORBIT , 3DSWIVEL , and 3DWALK commands are available from the Display panel of the Point Cloud contextual tab:
    • Use the Object option of the UCS command to align the UCS with the nearest point on
      a point cloud or one of its planar segments (if the point cloud includes segmentation
      data from Autodesk ReCap).

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