Unroll

Menu

This tool is accessible via the 'Tools > Projection > Unroll' menu.

Description

This method 'unrolls' a point cloud from a cylindrical (or conical) shape onto a plane:

Cylindrical shape to unroll

Cylindrical shape unrolled

Unrolled cone

Procedure

Select a single cloud then start this tool.

Cylinder

'Unroll cylinder' dialog

To unroll a cylindrical shape, the parameters are:

• axis of revolution (X, Y or Z)
• cylinder radius
• and optionally a point on the axis (otherwise CloudCompare can try to guess it by computing the gravity center of the point cloud)

'Unroll angular zero and sign' dialog

Cone

Since version 2.9, this method unrolls a cone in a way that preserves surfaces (as if the cone was 'rolling' on a planar surface).

'Unroll cone' dialog

To unroll a conical shape, the parameters are:

• axis of revolution (X, Y or Z)
• half angle (this is the aperture angle at the cone apex) in degrees
• the cone apex position in 3D

Straightened cone

This mode was corresponding to the 'Cone' unrolling mode in version 2.8 and prior.

This method unrolls a cone-shaped cloud as if it was a cylinder, by first 'straightening' the cone walls.

'Unroll straightened cone' dialog

To unroll a straightened conical shape, the parameters are:

• axis of revolution (X, Y or Z)
• half angle (this is the aperture angle at the cone apex - in degrees)
• the cone apex position
• the base radius of the 'straightened' cone (= cylinder)