Unroll: Difference between revisions
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[[Image:Cc_unroll_result.jpg|frame|center|Cylindrical shape unrolled]] | [[Image:Cc_unroll_result.jpg|frame|center|Cylindrical shape unrolled]] | ||
[[Image:Cc_unroll_cone_example.jpg|frame|center|Unrolled cone]] | [[Image:Cc_unroll_cone_example.jpg|frame|center|Unrolled cone]] | ||
Since version 2.13, it is now possible to: | |||
* define a custom 3D axis | |||
* init the unrolling parameters with an existing cylinder or cone entity present in the database | |||
* output the unrolled cloud in an arbitrary coordinate system | |||
== Procedure == | == Procedure == | ||
Revision as of 17:36, 6 February 2025
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:
Since version 2.13, it is now possible to:
- define a custom 3D axis
- init the unrolling parameters with an existing cylinder or cone entity present in the database
- output the unrolled cloud in an arbitrary coordinate system
Procedure
Select a single cloud then start this tool.
Cylinder
To unroll a cylindrical shape, the parameters are:
- axis of revolution (X, Y or Z)
- cylinder radius
- optionally a point on the axis (otherwise CloudCompare can try to guess it by computing the gravity center of the point cloud)
- since version 2.11, it is also possible to specify the angular range. By default it's [0-360], but you can input any angular value, and even multiple revolutions.
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).
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.
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)
Export deviation scalar field
A checkbox named 'Export deviation scalar field' allows to compute for each point its radial distance to the theoretical unrolling shape (cylinder or cone). A new scalar field will be added to the output cloud.