Command Element

Description

Modifies a marker element.

Format

<Reference_Marker

     id                  = "integer"

     pos_x               = "real"

     pos_y               = "real"

     pos_z               = "real"

     a00                 = "real"

     a10                 = "real"

     a20                 = "real"

     a01                 = "real"

     a11                 = "real"

     a21                 = "real"

     a02                 = "real"

     a12                 = "real"

     a22                 = "real"

     rm_id               = "integer">

 </Reference_Marker>

Attributes

id

The element identification number (integer>0).  This number is unique to all Reference_Marker elements.

pos_x, pos_y, pos_z

The x, y, and z coordinates of the marker origin specified in terms of the global frame. pos_x defines the x-coordinate of the origin, pos_y defines the y-coordinate of the origin, and pos_z defines the z-coordinate of the origin.

a00 a01 a02

a10 a11 a12

a20 a21 a22

Elements of the transformation matrix defining the orientation of the Reference_Marker with respect to the global frame.

{a00 a10 a20}defines directions cosines of the x-axis.

{a01 a11 a21}defines directions cosines of the y-axis.

{a02 a12 a22}defines directions cosines of the z-axis.  The nine elements define a 3x3, orthonormal matrix.

This means that the nine numbers must satisfy the following conditions:

rm_id

Specifies the ID of the Reference_Marker for which the position and orientation of the current marker are to be defined.

Example

The following example modifies a Reference_Marker on a rigid body.

<Reference_Marker

     id                  = "1012"

     pos_x               = "1.414"

     pos_y               = "3.14159"

     pos_z               = "1.61804"

     a00                 = "0."

     a10                 = "1."

     a20                 = "0."

     a01                 = "0.041630503"

     a11                 = "0."

     a21                 = "0.99913307"

     a02                 = "0.99913307"

     a12                 = "0."

     a22                 = "-0.04163050">

     rm_id               = 101

 </Reference_Marker>

Command Element

Description

Modifies a MARKER element.

Declaration

def MARKER(id, QP=[], ZP=[], XP=[], REULER=[], RM=0):

Attributes

id

Element identification number (integer>0).  This number is unique among all the MARKER elements.

QP

Specifies the coordinates of MARKER with respect to RM.

ZP

Specifies a point with respect to RM, denoting the direction of Z axis from QP.

XP

Specifies a point with respect to RM, denoting the direction of X axis from QP.

REULER

Specifies the Euler angles of MARKER with respect to RM.

RM

An optional attribute that specifies the Reference Marker ID.  If specified, the position and orientation of the MARKER is assumed to be with respect to the reference marker.  The default ID is 0, which refers to the global reference frame.

Comments

See Reference_Marker

Example

The following example modifies a MARKER on a rigid body.

MARKER(1012, QP=[1.414,3.14159,1.61804], ZP=[0.99913307,0, -0.04163050], XP=[0, 1, 0])