5.12.4. Transformation Options

TRANSFORMATION = YES

NO

Turns the transformation option on or off.

WriteTransformedMesh = YES

NO

Flag to enable the transformed mesh's output for mapping. This option enables you to control the success of the transformation. If set to YES, you must define a TransformedMeshFile (see Input and Output Meshes).

Mesh transformation is possible with three options:

  • TRAFO_OPTION is required

    • Iterative Closest Point (ICP)

    • Four-Points-Congruent Sets (4PCS)

  • TRAFO_OPTION is not required

    • User-defined translation and rotation

Use 4PCS with caution since it is fully automatic and might not transform stress-tensors and fiber orientations properly between the different coordinate systems. The ICP algorithm is recommended.

User-defined translation and rotation options are listed below after 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

Define nodal pairs for initial mesh alignment for the ICP algorithm. Up to ten nodal pairs can be defined, and a minimum of three nodal pairs must be defined. The first integer refers to a node ID in the source mesh. The second integer refers to a node ID in the target mesh. The two IDs must be separated with a space, and each nodal pair must be on separate lines.

Additional Transformations = INTDefine the number of additional transformations to be done using the ICP algorithm.
AddTrafo#i = INTDefine as many additional transformation IDs as defined for Additional Transformations. INT represents the element set ID to add to the algorithm.
AddNodalPair#i = INT INTUse this option to define 4 nodal pairs for additional mesh alignment for the ICP algorithm.
MAX_NUM_ITER = INTMaximum number of iterations to be performed by the 4PCS algorithm.
GLOBAL_ERR = DOUBLEGlobal error measure to accept transformation as best fit (4PCS).

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).

Furthermore, you can specify a set of user-defined transformations to be performed. They are executed in the order of input:

RotateSRC =DOUBLE;X

DOUBLE;Y

DOUBLE;Z

DOUBLE; DOUBLE DOUBLE DOUBLE

Rotates the source mesh at an angle (first value) in degrees around the defined axis. Predefined axis are X, Y, and Z. To use a user-defined axis, seperate three double values with a space, following a semicolon (;x y z).
MoveSRC = DOUBLE DOUBLE DOUBLE

Moves the source mesh along a user-defined vector (x y z).

ScaleSRC = DOUBLE

Scales the source mesh along the origin using the defined scale factor.

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

ChangeUnitSystem = YES

NO

Activates or deactives unit system conversion.

SourceUnitSystem =kg − m − s

ton − mm − s

kg − mm − ms

g − mm − ms

lb − in − s

Provide information about the source unit system if unit system conversion is activated.

TargetUnitSystem =kg − m − s

ton − mm − s

kg − mm − ms

g − mm − ms

lb − in − s

Provide information about the target unit system if unit system conversion is activated.