5.15.6. Transformation Options

TRANSFORMATION = YES

NO

Turns on or off the transformation option.

WriteTransformedMesh = YES

NO

Flag to output the transformed mesh to use for mapping. This enables control of the transformation's success. If this option is equal to YES, you must define a TransformedMeshFile (see Input and Output Meshes for TFP Reinforcing Patch Handling).

There are three available methods for performing mesh transformation:

  • TRAFO_OPTION is required:

    • Iterative Closest Point (ICP)

    • Four-Points-Congruent Sets (4PCS)

  • TRAFO_OPTION is not required:

    • User-defined translation and rotation

Use the 4PCS method with caution, since it is fully automatic and may not accurately transform stress tensors and fiber orientations between the different coordinate systems. The ICP algorithm is the recommended approach.

The user-defined translation and rotation options are listed underneath TRAFO_OPTION.


Note:  Transformation options are used to transform the source mesh.


TRAFO_OPTION = 4PCS

ICP

Flag for choosing a transformation option.
NodalPair#i = INT INT

Defines nodal pairs for initial mesh alignment for ICP algorithm. A minimum of three nodal pairs must be defined, and the maximum definition for this option is ten nodal pairs. The first integer refers to a node ID in the source mesh, and the second integer refers to a node ID in the target mesh. These intergers must be separated with spaces, and defined nodal pairs must be on seperate lines.

MAX_NUM_ITER = INTMaximum number of iterations to be performed by the 4PCS algorithm.
GLOBAL_ERR = DOUBLEGlobal error messure to accept transformation as best fit 4PCS algorithm.

MATCHING_POINT_DIST = DOUBLE

Maximum distance between points so that they are accepted as matching (4PCS).

PERCENTAGE_OF_MATCHING_POINTS = DOUBLE

Percentage of matching points to accept the transformation (4PCS).

Additionally, a custom sequence of user-defined transformations can be applied. These transformations are executed in the order in which they are specified and multiple transformations may be defined.

RotateSRC = DOUBLE;X

DOUBLE;Y

DOUBLE;Z

DOUBLE; DOUBLE DOUBLE DOUBLE

The source mesh rotates by a specified angle (first value, in degrees) around a defined axis. Predefined axes include X, Y, and Z. Alternatively, a custom axis can be specified by providing three space-separated floating-point values following a semicolon (; x y z).
MoveSRC = DOUBLE DOUBLE DOUBLE The source mesh moves along the user-defined vector (x y z).
ScaleSRC = DOUBLEThe source mesh scales around the origin using the defined scale factor.

In addition to the transformation options, you can convert the unit systems:

ChangeUnitSystem = YES

NO

Activates or deactivates unit system conversion.

SourceUnitSystem = kg − m − s

ton − mm − s

kg − mm − ms

g − mm − ms

lb − in − s

If unit system conversion is actived, provides information about the source unit system.

TargetUnitSystem = kg − m − s

ton − mm − s

kg − mm − ms

g − mm − ms

lb − in − s

If unit system conversion is activated, provides information about the target unit system.