Geometry & modeling
Point cloud
Definition
A point cloud is a set of measured coordinates that sample the surface or surroundings of a physical object in three dimensions. The points may also carry colour or intensity, but they do not by themselves define connected faces, exact curves, material volume, or CAD feature history.
Also known as: 3D point cloud, scan point cloud
Updated
What the points store#
Autodesk describes a point cloud as a large collection of points placed in a three-dimensional coordinate system. A scanner or photogrammetry workflow estimates each point's position. Some formats also store colour, return intensity, classification, or scanner information.
The density of points is not the same as accuracy. Capture uncertainty, surface reflectivity, viewing angle, occlusion, registration, and later filtering can all affect the samples. A dense cloud can still contain systematic error or miss a hidden surface completely.
Point cloud, mesh, and CAD body#
A point cloud contains samples without explicit connections between them. A mesh connects vertices into polygons, normally triangles, to form a surface. A B-Rep CAD body represents faces, edges, curves, and topology as engineering geometry.
Converting between those representations requires interpretation. Meshing decides which points belong to one surface and how gaps are closed. Scan-to-CAD work then fits or rebuilds planes, cylinders, curves, and freeform surfaces. The point cloud does not contain the original sketches, dimensions, tolerances, or feature order.
Use in reverse engineering#
SOLIDWORKS Design 2026 accepts point-cloud or mesh files as scan data, then describes preparation, sectioning, surface creation, deviation checking, trimming, knitting, and solid creation.
Preserve the original cloud as measurement evidence. Perform filtering, alignment, meshing, and feature fitting on derived data, and record the coordinate system and assumptions used. The scan-to-CAD workflow explains why an editable replacement model should recover functional relationships rather than merely connect every measured point.
Sources
Related terms
Mesh
A mesh represents a shape as a surface of small flat polygons, almost always triangles, joined at shared edges and vertices. Meshes work well for rendering, games, and 3D printing, but they have no true faces, edges, or exact curves, so they are hard to dimension or edit as engineering geometry.
Surface modeling
Surface modeling creates and edits zero-thickness faces that define the outer boundary of a shape without enclosing material or volume. It is used for complex curvature, product styling, face repair, and hybrid workflows where surfaces are later stitched, knit, or thickened into a solid.
B-Rep
B-Rep is the way professional CAD kernels describe a solid: by its boundary, made of exact surfaces (faces), the curves where they meet (edges), and the points where edges end (vertices). Because the geometry is exact and the topology is explicit, B-Rep models can be measured, filleted, dimensioned, and manufactured precisely.