BlockedPoints

R2026b

Display and modify blocked points in pcviewer

Since R2026b

Description

A BlockedPoints object represents an octree-optimized point cloud in a pcviewer scene. When pcviewer generates an octree to improve visualization performance for large point clouds, the Points objects in the scene are converted to BlockedPoints objects. You can use the properties of the BlockedPoints object to access the associated point cloud data and control the appearance and behavior of the point cloud in the scene.

Properties

Data — Blocked point cloud

Read-only: blockedPointCloud object

This property is read-only.

Point cloud data, specified as a blockedPointCloud object.

ColorSource — Source of the color data

"auto" (default) | "X" | "Y" | "Z" | "Color" | "Intensity" | "Row" | "Column" | "Range" | "Azimuth" | "Elevation"

Source of the color data, specified as one of:

• "auto" — Uses the Color property of the input point cloud, if available. Otherwise, uses "Intensity" if available. If neither is available, uses the z-coordinates of the vertices.

• "X" — Use the x-coordinates of the vertices.

• "Y" — Use the y-coordinates of the vertices.

• "Z" — Use the z-coordinates of the vertices.

• "Color" — Use RGB color values stored in the point cloud.

• "Intensity" — Use intensity values stored in the point cloud.

• "Row" — Use row indices of an organized point cloud.

• "Column" — Use column indices of an organized point cloud..

• "Range" — Use range values when available.

• "Azimuth" — Use azimuth values stored in the point cloud.

• "Elevation" — Use elevation values stored in the point cloud.

• "Custom" — Use the values specified by the Color property.

PointSize — Point size

1.0 (default) | positive scalar

Point size, specified as a positive scalar in pixels.

Transformation — Transformation applied to point cloud in scene

rigidtform3d (default) | affinetform3d | simtform3d | transltform3d

Transformation applied to the point cloud in the scene, specified as a rigidtform3d (Image Processing Toolbox), affinetform3d (Image Processing Toolbox), simtform3d (Image Processing Toolbox), or transltform3d (Image Processing Toolbox).

Alpha — Transparency of point cloud

[0,1] (default) | numeric scalar

Transparency of point cloud, specified as a numeric scalar in the range [0,1].

Visible — Display point cloud in scene

"on" (default) | "off" | 0 or false | 1 or true

Display point cloud in scene, specified as "on" or "off", or as a numeric or logical 0 (false) or 1 (true). A value of "on" is equivalent to true and shows the points magnified. A value of "off" is equivalent to false and shows points unmagnified, as they would appear from the position of the camera.

Examples

Visualize Large Point Cloud

Download two point clouds from the U.S. Geological Survey (USGS) 3D Elevation Program (3DEP), covering the University of Utah campus and adjacent Wasatch Mountain foothills. The combined point cloud contains approximately 60 million RGB points.

baseURL = "https://rockyweb.usgs.gov/vdelivery/Datasets/Staged/Elevation/LPC/Projects/Wasatch_Fault_UT_LiDAR/UT_Wasatch_L4_2013/LAZ/";

tiles = [
    "USGS_LPC_Wasatch_Fault_UT_LiDAR_12TVL2900012000.laz"
    "USGS_LPC_Wasatch_Fault_UT_LiDAR_12TVL3000012000.laz"
    "USGS_LPC_Wasatch_Fault_UT_LiDAR_12TVL2900013000.laz"
    "USGS_LPC_Wasatch_Fault_UT_LiDAR_12TVL3000013000.laz"    
];

Read each tile as a point cloud. Download tiles only if they are not already stored locally.

pcArray = pointCloud.empty;
for i = 1:numel(tiles)
    localFile = fullfile(tempdir, tiles(i));
    if ~exist(localFile,"file")
        websave(localFile, baseURL + tiles(i));
    end
    reader = lasFileReader(localFile);
    pcArray(i) = readPointCloud(reader);
end

Concatenate the tiles into a single point cloud.

pc = pccat(pcArray);

Visualize the large point cloud using the returned BlockedPoints object.

[pcview,blockedPts] = pcviewer(pc);

Version History

Introduced in R2026b