Overview of Point Clouds

Drawings SDK provides two set of classes to work with point clouds attached to .dwg files:

The first set may be defined as "legacy" one at the moment. It corresponds to working with attachments represented by .pcg or .isd files.
The second set of classes corresponds to working with attachments represented by .rcs/.rcp files.

The new set of classes is distinguished by the presence of a suffix "Ex" in the class names. There is no such suffix in the names of the legacy set of classes.

Both new and legacy sets use two different types of objects to represent point clouds in a drawing: point cloud definitions and point cloud entity objects. The relationship between these two kinds of objects is very similar to the relationship between a block definition and block reference objects or between a raster image definition and raster image entity objects.

Point cloud definition objects define a point cloud object inside the database and contain the information about the linked point cloud file, such as the file path and file type.

Point cloud definition objects are stored in a special point cloud dictionary.

For legacy point clouds definitions the dictionary named ACAD_POINTCLOUD_DICT. For new point clouds definitions the dictionary named ACAD_POINTCLOUD_EX_DICT.

Point cloud entity objects are references to corresponding point cloud definition objects and represent point clouds inside the drawing.

Point cloud entities can be added to model space or paper space as common entities and contain a set of properties that defines a representation: transformations, intensity, clipping, etc.

The documentation will consider working with both sets of classes separately.

The main list of extension modules to work with point clouds in the Drawings SDK is a following:

Module name:	AcDbPointCloudObj.tx	PointCloudHost.tx
Repository/Archive:	Drawing	Drawing
The path to the sources in the repository:	Drawing/Source/database/DbPointCloudObj	Drawing/Examples/ExPointCloudHost
Example of the path to the .lib files in the archive:	Drawings_vc15_amd64dll_22.1/lib/vc15_amd64dll/ AcDbPointCloudObj.lib	Drawings_vc15_amd64dll_22.1/lib/vc15_amd64dll/PointCloudHost.lib
Example of the path to the executable files in the archive:	Drawings_vc15_amd64dll_22.1/exe/vc15_amd64dll/ AcDbPointCloudObj_22.1_15.tx	Drawings_vc15_amd64dll_22.1/exe/vc15_amd64dll/PointCloudHost_22.1_15.tx

AcDbPointCloudObj.tx is designed to work with entities and definitions of point clouds in .dwg.

PointCloudHost.tx is designed to load point cloud data from external files like .pcg or .rcs/.rcp and to support visualization of point clouds attached to .dwg files.

See Also