Scripted elements API

This reference describes functions and data structures necessary for the implementation of “scripted elements”.

See also

If you don’t know about the concept yet, take a look at the Scripted elements introduction.

The `dialog` function

💡 Notes:

The main purpose of this function is to use display a script dialog and allow the user to enter element parameters.
All tokens of other elements can be accessed within this function.

Signature

def dialog(context, params):

Parameter `context`

The context contains the following members:

Name	Role	Remarks
.data	UDE data storage access	see “calculate” Function
.stages	Current stage	List containing stage index of current stage
.total_stages	Number of stages	Valid stage indices are 0 to total_stages - 1
.calc	Function to calculate preview	See below
.result	Directly set preview	see “calculate” Function
.is_new_element	Flag if element creation	True on (edit) creation, false on recalc
.name	Name of created element	Read/write attribute Ignored on recalc and script execution
.error	Last error text from preview calculation	Empty if no error occurred
.edit_element	Reference to edited element	Only available during element editing
.recalc_element	Reference to element used in project recalculation

Parameter `params`

The params contain a map of parameter values. It is only filled on element edit and contains the current parameters of the element.

Return value

The function must return a map containing the new element parameters.

If no map is returned the edit/creation is regarded as aborted by the user.

Calculating a preview

To calculate a preview, the context.calc() function can be invoked. It takes the following parameters:

Name

Role

params

A map of parameters to be used for preview calculation

stages

Optional: A list of stage indices to calculate a preview in

dialog

Optional: A script dialog to message when preview calculation was successful.
If a calculation result is true, the dialog event handler will receive the event string ‘calculated’,
otherwise it will receive ‘error’.

A call to this function will return immediately. The calculation is invoked asynchronously in a separate python instance.

See also

A preview calculation is implemented in the example offset_point_v2.

The `calculation` function

💡 Notes:

It is not possible to call script commands or read tokens from within this function. (Do not call gom.app.project....)
The function should loop over all stages to be calculated and set a computation result for each stage.

Signature

def calculation(context, params):

Parameter `context`

The context contains the following members:

Name	Role	Remarks
.data[stage]	UDE data storage access	see below
.stages	Current indices	List containing stage indices to calculate
.total_stages	Number of stages	Valid stage indices are 0 to total_stages - 1
.result[stage]	Directly set preview	see below
.is_new_element	Flag if element creation	True on (edit) creation, false on recalc
.name	Name of created element	Read/write attribute Ignored on recalc and script execution
.error[stage]	Used to assign an error text	Will set the element to not computed in the given stage
.edit_element	Reference to edited element	Only available during element editing
.recalc_element	Reference to element being computed	Only available during non-interactive calculation
.progress_stages_computing	Number of stages which have started to compute	Used to display progress information
.progress_stages_total	Number of stages which have to be computed	Used to display progress information

Attribute `context.data[]`

The context.data is a list allowing to read or write additional data. The list is indexed with a stage index. The additional data is stored within the project, so the gom application must be able to serialize the provided data.

context.data[0] = value
value = context.data[0]

Attribute `context.result[]`

This is a write only list used to set computation results. The context.result[] should be set for each stage index listed in context.stages.

The format to write must match the type of the script element. For available result types, see Scripted actuals - Return values and Scripted checks - Return values.

Return value

On success the function must return True, otherwise False.

Scripted actuals - Return values

See also

The section Python API Examples - scripted_actuals provides an example for each element type.

Point

Element Type:: Plain 3D point
Result:: Point coordinate

result = (x,y,z)
result = gom.Vec3D

Distance

Element Type:: Two point distance
Result:: Start and end point of distance

result = { 'point1': (x,y,z), 'point2': (x,y,z) }
result = { 'point1': gom.Vec3D, 'point2': gom.Vec3D }

Value Element

Element Type:: Plain value (only real values supported)
Result:: any double value

result = x

Circle

Element Type:: 2D Circle with direction
Result:: A center point, direction vector and radius (double)

result = { 'center' : gom.Vec3D, 'direction' : gom.Vec3D, 'radius' : double }

Curve

Element Type:: 3D polyline
Result:: A curve can be made up by an array of subcurves. Each subcurve is a polyline. A closed curve will be created, if first point = last point.
As an option, a creation plane can be added.

result = [ { 'points': [gom.Vec3D, gom.Vec3D, ...] } ]

# Optional: Curve with additional creation plane
result = {
  'curves': [{'points': [gom.Vec3D, ...]],
  'plane' : {'normal' : gom.Vec3D, 'distance' : float}
}

Surface Curve

Element Type:: 3D polyline with normals
Result:: Like a curve with additional normal data, i.e. each surface curve can be made up by an array of subcurves.

result = {
  'default': [
    {'points': [gom.Vec3d, gom.Vec3d, ...], 'normals': [gom.Vec3d, gom.Vec3d, ...]},
    {...}, 
    ...
  ]
} 

Section

Element Type:: 3D polyline with normals
Result:: Parameters ‘plane’, ‘cylinder’ and ‘cone’ are optional. They denote the creation geometry. You can only use one of them. Argument is a corresponding trait.

result = {
  'curves': [{'points': [(x, y, z), ...], 'normals': [(x, y, z), ...]}, ...], 
  'plane' : {'normal' : (x, y, z), 'distance' : float}, 
  'cylinder': ..., 
  'cone' : ...
}

Point Cloud

Element Type:: Set of 3D points
Result:: A set of points. The ‘normals ‘attribute is optional.

result = { 'points' :  [ gom.Vec3D, gom.Vec3D, ... ] , 'normals' : [ gom.Vec3D, gom.Vec3D, ... ] }

Surface

Element Type:: Mesh
Result:: Defines a triangulation. The vertices attribute defines all points. The triangle attribute defines triangles between these points using indices into the vertex list.

result = { 'vertices': [ (x,y,z) ], 'triangles':  [ (v0,v1,v2) ] }

Cone

Element Type:: Cone
Result:: Accepts any Cone Trait

result = {'default' : {'point1': gom.Vec3d, 'radius1': float, 'point2': gom.Vec3d, 'radius2': float} }

Caution

Due to the internal represenstation of a Cone Element, the direction of the vector point1 -> point2 is always from the smaller to the larger circle (radius1 < radius2).

If you specify radius1 > radius2 in the creation parameters, [point1; radius1] and [point2; radius2] are swapped automatically.

Cylinder

Element Type:: Cylinder
Result:: Accepts any Cylinder Trait

result = Reference

result = {'default' : {'point': gom.Vec3d, 'radius': float, 'direction': gom.Vec3d, 'inner' : bool} }

Volume defects

Element Type:

Volume defects

Result:

A list of meshes defined by vertices and triangles.

The vertices attribute is a [python array] – one entry for each defect – of numpy arrays (np.array) of Vec3d.

The triangle attribute defines triangles between the points of each mesh using indices to the vertex lists.

The ‘outer_hull’ parameter can optionally be set to a reference of a mesh element of the project. This mesh will be copied and used as an outer hull for the defect element. Alternatively, ‘outer_hull_vertices’ and ‘outer_hull_triangles’ can be given as explicit outer hull mesh definition.

result = {
  'vertices': [ np.array((x,y,z), (x,y,z), ... ), np.array((x,y,z), (x,y,z), ...), ... ],
  'triangles':  [ np.array((v0,v1,v2), (v0,v1,v2), ... ), np.array((v0,v1,v2), (v0,v1,v2), ...), ... ],
  'outer_hull' : gom.Reference     # optional OR
  'outer_hull_vertices': np.array((x,y,z),...), 'outer_hull_triangles': np.array((v0,v1,v2),...) 
}

2D Volume Defects

Element Type:

2D volume defects element of curves

needed for the P201 package

Result:

Requires a list/array of lists/arrays of Vec3ds.

A list of points represents the polygon (curve) of one 2d volume defect. The list of lists of points represents all 2d volume defects that shall be included in the element.

result = {
  'curves': [ [gom.Vec3d, gom.Vec3d, ...], [gom.Vec3d, gom.Vec3d, ...], ... ],
  'outer_contours': [ [gom.Vec3d, gom.Vec3d, ...], [gom.Vec3d, gom.Vec3d, ...], ... ]
}

or

result = {
  'curves': [ [gom.Vec3d, gom.Vec3d, ...], [gom.Vec3d, gom.Vec3d, ...], ... ],
  'outer_contours': [ np.array([(x00,y00,z00), (x01,y01,z01), ...], dtype=np.float) ]
}

Volume

Element Type:

New volume data

Result:

Accepts a numpy array with voxel data and a transformation.

The numpy array’s shape denotes the resulting volume shape. The ‘dtype’ can be one of (UINT16, BYTE, INT16, INT16, INT32, UINT32, FLOAT, DOUBLE).

The transformation can be a gom.Mat4x4 (affine transformation) or a gom.Vec3d (scaling along x/y/z axis only)

result = { 'voxel_data' : np.array (), 'transformation' : (gom.Mat4x4 | gom.Vec3d) }

Volume material map

Element Type:

Attach material labels to volume element

Result:

Creates a new volume element copy with attached material labels.

First parameter is a numpy array of type UINT8 of the size of the volume. The values are the material index per voxel. Background has Index 0.

The second parameter is a list of floating point grey values that are the representative grey values of the background and the materials.

The third parameter is a reference to the volume element, to which material labels should be attached.

result = {
  'material_labels_draft' : np.array (),
  'material_grey_values_draft' : [background, material 1, ...],
  'volume_reference_draft' : Reference
}

Volume Section

Element Type:

Volume Section

Result:

Accepts a numpy array with pixel data and a transformation.

The numpy array’s shape denotes the resulting volume section shape. The ‘dtype’ must be numpy.float32.

The transformation is a gom.Mat4x4 (affine transformation)

result = { 'pixel_data' : np.array (), 'transformation' : gom.Mat4x4 }

Volume Region

Element Type:

Volume Region

Result:

Accepts a numpy array of the region data. The ‘dtype’ must be UINT_8. This array can be smaller than the volume grid.

The offset parameter defines the location of the first voxel in the numpy array of the volume region.

This scripted element requires specifying a reference to a volume element. This can be a volume or linked volume element.

result = {
  'volume_element': Reference,
  'offset': gom.Vec3d,
  'voxel_data': np.array ()
}

Scripted checks - Return values

Scripted Checks extend the concept of scripted actual elements to be able to calculate custom inspections based on python scripts.

Supported Element Types

The following element types are currently supported:

Scalar

Element Type:: Scalar check:
A single scalar value is assigned to an element
Result:: A nominal and actual double value are set, and a reference to element which was checked.

result = {"nominal" : double, "actual" : double, "reference" : gom.Reference }

Scalar Surface

Element Type:

Surface check:
A scalar deviation value is assigned to each point of a mesh.

Result:

A list of deviation values for each point of a mesh. The mesh is also set as “reference” parameter.

The number of points of the mesh and the “deviation_values” array must match.

result = { "deviation_values" : np.array(dtype=np.float32), "reference" : gom.Reference }

Scalar Curve

Element Type:

Curve check:
A scalar deviation value is assigned to each point on a curve.

Result:

A list of nominal and actual values for each point of a curve. The deviation values are calculated automatically as a difference between both.

The curve is also set as “reference” parameter.

The number of points of the curve and the value arrays must match.

result = { "actual_values" : double, 'nominal_values': double, "reference" : gom.Reference}

Scripted elements API

The dialog function

Signature

Parameter context

Parameter params

Return value

Calculating a preview

The calculation function

Signature

Parameter context

Attribute context.data[]

Attribute context.result[]

Return value

Scripted actuals - Return values

Point

Distance

Value Element

Circle

Curve

Surface Curve

Section

Point Cloud

Surface

Cone

Cylinder

Volume defects

2D Volume Defects

Volume

Volume material map

Volume Section

Volume Region

Scripted checks - Return values

Supported Element Types

Scalar

Scalar Surface

Scalar Curve

The `dialog` function

Parameter `context`

Parameter `params`

The `calculation` function

Parameter `context`

Attribute `context.data[]`

Attribute `context.result[]`