10th October 2016 Grzegorz Ciępka

Point Cloud status in CAD software

Probably most point clouds are captured to be used in CAD software as a most accurate reality representation possible. This is correct, but not actually explain how to make use of a point cloud and what are the possibilities of having this technology available in the design process. We will try to explain the very basics of point clouds behaviour in the CAD environment.

Picture of simple point cloud

From the CAD software perspective point clouds are external files, that can be attached to any design file just like any other attachable elements. Point cloud files can be treated as referenced design files from foreign software, that can be viewed in various modes but are not really editable.

Screen of Attach menu in MicroStation 10 Connect
Screen of Attach point cloud button in AutoCad 2016

All attached elements in CAD have in common that they appear as a box filled with attachment’s content. This simple fact of having only one object (the container) to be listed in a CAD file structure is one of the key pieces of making point clouds possible in a design space.

Point cloud files are simple databases, where every record is a counterpart of a point in space. This point has few properties, that include at least three-dimensional position, usually in form of X, Y and Z coordinates in the same coordinate system. You can read more on our previous post.

When point cloud file is attached to the design file this database is translated into a three-dimensional image, where every record gets an appearance as a visible point in a design space. Millions of points displayed this way make up the realistic representation of an object or place recorded within point cloud file.

Screen showing piece of point cloud with a box

Point clouds are just one “point cloud” object, not a bundle of individual points. Although it is technically possible to make “cloud of points” out of individual “Point / Dot” CAD objects. Any present software on any workstation would not be able to display such complicated CAD file, because software limit of displayed objects are usually around few thousand objects at once and a point cloud has usually millions of points.

Screen from MicroStation 10 Connect showing point cloud object and it's properties

Point clouds are very successful attempt to present a very high number of data in a displayable form. All this is possible because, in contrast to typical CAD objects, individual points in a cloud have only those properties that are needed to be displayed in a proper position and in a correct colour. All further properties like point size, transparency are unified for the whole point cloud. This along with a few filtering options makes possible to display a huge number of points even on the relatively old workstation.

Screen from AutoCAD 2016 showing point cloud object and it's properties