4.3.1.37. NXorientation

Status:

base class, extends NXobject

Description:

legacy class - recommend to use NXtransformations now

Description for a general orientation of a component - used by NXgeometry

Symbols:

No symbol table

Groups cited:

NXgeometry

Structure:

@default: (optional) NX_CHAR

Declares which child group contains a path leading to a NXdata group.

It is recommended (as of NIAC2014) to use this attribute to help define the path to the default dataset to be plotted. See https://www.nexusformat.org/2014_How_to_find_default_data.html for a summary of the discussion.

value: (optional) NX_FLOAT (Rank: 2, Dimensions: [numobj, 6]) {units=NX_UNITLESS}

The orientation information is stored as direction cosines. The direction cosines will be between the local coordinate directions and the reference directions (to origin or relative NXgeometry). Calling the local unit vectors (x’,y’,z’) and the reference unit vectors (x,y,z) the six numbers will be [x’ dot x, x’ dot y, x’ dot z, y’ dot x, y’ dot y, y’ dot z] where “dot” is the scalar dot product (cosine of the angle between the unit vectors). The unit vectors in both the local and reference coordinates are right-handed and orthonormal.

The pair of groups NXtranslation and NXorientation together describe the position of a component.

GEOMETRY: (optional) NXgeometry

Link to another object if we are using relative positioning, else absent

Hypertext Anchors

List of hypertext anchors for all groups, fields, attributes, and links defined in this class.

NXDL Source:

https://github.com/nexusformat/definitions/blob/main/base_classes/NXorientation.nxdl.xml