fabex.utilities.operation_utils

Fabex ‘operation_utils.py’ © 2012 Vilem Novak

Main functionality of Fabex. The functions here are called with operators defined in ‘ops.py’

Functions

get_operation_sources(o)	Get operation sources based on the geometry source type.
reload_paths(o)	Reload the CAM path data from a pickle file.
update_operation(self, context)	Update the CAM operation based on the current context.
source_valid(o, context)	Check the validity of a geometry source.
operation_valid(self, context)	Validate the current CAM operation in the given context.
chain_valid(chain, context)	Check the validity of a chain of operations within a given context.
update_operation_valid(self, context)
update_chipload(self, context)	Update the chipload based on feedrate, spindle RPM, and cutter
update_offset_image(self, context)	Refresh the Offset Image Tag for re-rendering.
update_Z_buffer_image(self, context)	Update the Z-buffer and offset image tags for recalculation.
update_image_size_y(self, context)	Updates the Image Y size based on the following function.
update_bridges(o, context)	Update the status of bridges.
update_rotation(o, context)	Update the rotation of a specified object in Blender.
update_rest(o, context)	Update the state of the object.
update_operation(self, context)	Update the CAM operation based on the current context.
update_zbuffer_image(self, context)	Update the Z-buffer image based on the active CAM operation.
get_chain_operations(chain)	Return chain operations associated with a given chain object.
get_change_data(o)	Check if object properties have changed to determine if image updates
check_memory_limit(o)	Check and adjust the memory limit for an object.
get_move_and_spin(o)
get_ambient(o)	Calculate and update the ambient geometry based on the provided object.
get_cutter_array(operation, pixsize)	Generate a cutter array based on the specified operation and pixel size.
check_min_z(o)	Check the minimum value based on the specified condition.
get_layers(operation, start_depth, end_depth)	Returns a list of layers bounded by start depth and end depth.
get_operation_axes(o)

Module Contents

get_operation_sources(o)

Get operation sources based on the geometry source type.

This function retrieves and sets the operation sources for a given object based on its geometry source type. It handles three types of geometry sources: ‘OBJECT’, ‘COLLECTION’, and ‘IMAGE’. For ‘OBJECT’, it selects the specified object and applies rotations if enabled. For ‘COLLECTION’, it retrieves all objects within the specified collection. For ‘IMAGE’, it sets a specific optimization flag. Additionally, it determines whether the objects are curves or meshes based on the geometry source.

Parameters:

o (Object) – An object containing properties such as geometry_source, object_name, collection_name, rotation_a, rotation_b, enable_A, enable_B, old_rotation_a, old_rotation_b, A_along_x, and optimisation.

Returns:

This function does not return a value but modifies the

properties of the input object.

Return type:

None

reload_paths(o)

Reload the CAM path data from a pickle file.

This function retrieves the CAM path data associated with the given object o. It constructs a new mesh from the path vertices and updates the object’s properties with the loaded data. If a previous path mesh exists, it is removed to avoid memory leaks. The function also handles the creation of a new mesh object if one does not already exist in the current scene.

Parameters:

o (Object) – The object for which the CAM path is being

update_operation(self, context)

Update the visibility and selection state of CAM operations in the scene.

This method manages the visibility of objects associated with CAM operations based on the current active operation. If the ‘hide_all_others’ flag is set to true, it hides all other objects except for the currently active one. If the flag is false, it restores the visibility of previously hidden objects. The method also attempts to highlight the currently active object in the 3D view and make it the active object in the scene.

Parameters:

context (bpy.types.Context) – The context containing the current scene and

source_valid(o, context)

Check the validity of a geometry source.

This function verifies if the provided geometry source is valid based on its type. It checks for three types of geometry sources: ‘OBJECT’, ‘COLLECTION’, and ‘IMAGE’. For ‘OBJECT’, it ensures that the object name ends with ‘_cut_bridges’ or exists in the Blender data objects. For ‘COLLECTION’, it checks if the collection name exists and contains objects. For ‘IMAGE’, it verifies if the source image name exists in the Blender data images.

Parameters:

• o (object) – An object containing geometry source information, including attributes like geometry_source, object_name, collection_name, and source_image_name.

• context – The context in which the validation is performed (not used in this function).

Returns:

True if the geometry source is valid, False otherwise.

Return type:

bool

operation_valid(self, context)

Validate the current CAM operation in the given context.

This method checks if the active CAM operation is valid based on the current scene context. It updates the operation’s validity status and provides warnings if the source object is invalid. Additionally, it configures specific settings related to image geometry sources.

Parameters:

context (Context) – The context containing the scene and CAM operations.

chain_valid(chain, context)

Check the validity of a chain of operations within a given context.

This function verifies if all operations in the provided chain are valid according to the current scene context. It first checks if the chain contains any operations. If it does, it iterates through each operation in the chain and checks if it exists in the scene’s CAM operations. If an operation is not found or is deemed invalid, the function returns a tuple indicating the failure and provides an appropriate error message. If all operations are valid, it returns a success indication.

Parameters:

• chain (Chain) – The chain of operations to validate.

• context (Context) – The context containing the scene and CAM operations.

Returns:

A tuple containing a boolean indicating validity and an error message

(if any). The first element is True if valid, otherwise False. The second element is an error message string.

Return type:

tuple

update_operation_valid(self, context)

update_chipload(self, context)

Update the chipload based on feedrate, spindle RPM, and cutter parameters.

This function calculates the chipload using the formula: chipload = feedrate / (spindle_rpm * cutter_flutes). It also attempts to account for chip thinning when cutting at less than 50% cutter engagement with cylindrical end mills by combining two formulas. The first formula provides the nominal chipload based on standard recommendations, while the second formula adjusts for the cutter diameter and distance between paths. The current implementation may not yield consistent results, and there are concerns regarding the correctness of the units used in the calculations. Further review and refinement of this function may be necessary to improve accuracy and reliability.

Parameters:

context – The context in which the update is performed (not used in this implementation).

Returns:

This function does not return a value; it updates the chipload in place.

Return type:

None

update_offset_image(self, context)

Refresh the Offset Image Tag for re-rendering.

This method updates the chip load and marks the offset image tag for re- rendering. It sets the changed attribute to True and indicates that the offset image tag needs to be updated.

Parameters:

context – The context in which the update is performed.

update_Z_buffer_image(self, context)

Update the Z-buffer and offset image tags for recalculation.

This method modifies the internal state to indicate that the Z-buffer image and offset image tags need to be updated during the calculation process. It sets the changed attribute to True and marks the relevant tags for updating. Additionally, it calls the getOperationSources function to ensure that the necessary operation sources are retrieved.

Parameters:

context – The context in which the update is being performed.

update_image_size_y(self, context)

Updates the Image Y size based on the following function.

update_bridges(o, context)

Update the status of bridges.

This function marks the bridge object as changed, indicating that an update has occurred. It prints a message to the console for logging purposes. The function takes in an object and a context, but the context is not utilized within the function.

Parameters:

• o (object) – The bridge object that needs to be updated.

• context (object) – Additional context for the update, not used in this function.

update_rotation(o, context)

Update the rotation of a specified object in Blender.

This function modifies the rotation of a Blender object based on the properties of the provided object ‘o’. It checks which rotations are enabled and applies the corresponding rotation values to the active object in the scene. The rotation can be aligned either along the X or Y axis, depending on the configuration of ‘o’.

Parameters:

• o (object) – An object containing rotation settings and flags.

• context (object) – The context in which the operation is performed.

update_rest(o, context)

Update the state of the object.

This function modifies the given object by setting its ‘changed’ attribute to True. It also prints a message indicating that the update operation has been performed.

Parameters:

• o (object) – The object to be updated.

• context (object) – The context in which the update is being performed.

update_operation(self, context)

Update the CAM operation based on the current context.

This function retrieves the active CAM operation from the Blender context and updates it using the updateRest function. It accesses the active operation from the scene’s CAM operations and passes the current context to the updating function.

Parameters:

context – The context in which the operation is being updated.

update_zbuffer_image(self, context)

Update the Z-buffer image based on the active CAM operation.

This function retrieves the currently active CAM operation from the Blender context and updates the Z-buffer image accordingly. It accesses the scene’s CAM operations and invokes the updateZbufferImage function with the active operation and context.

Parameters:

context (bpy.context) – The current Blender context.

get_chain_operations(chain)

Return chain operations associated with a given chain object.

This function iterates through the operations of the provided chain object and retrieves the corresponding operations from the current scene’s CAM operations in Blender. Due to limitations in Blender, chain objects cannot store operations directly, so this function serves to extract and return the relevant operations for further processing.

Parameters:

chain (object) – The chain object from which to retrieve operations.

Returns:

A list of operations associated with the given chain object.

Return type:

list

get_change_data(o)

Check if object properties have changed to determine if image updates are needed.

This function inspects the properties of objects specified by the input parameter to see if any changes have occurred. It concatenates the location, rotation, and dimensions of the relevant objects into a single string, which can be used to determine if an image update is necessary based on changes in the object’s state.

Parameters:

o (object) – An object containing properties that specify the geometry source and relevant object or collection names.

Returns:

A string representation of the location, rotation, and dimensions of

the specified objects.

Return type:

str

check_memory_limit(o)

Check and adjust the memory limit for an object.

This function calculates the resolution of an object based on its dimensions and the specified pixel size. If the calculated resolution exceeds the defined memory limit, it adjusts the pixel size accordingly to reduce the resolution. A warning message is appended to the object’s info if the pixel size is modified.

Parameters:

o (object) – An object containing properties such as max, min, optimisation, and info.

Returns:

This function modifies the object’s properties in place and does not

return a value.

Return type:

None

get_move_and_spin(o)

get_ambient(o)

Calculate and update the ambient geometry based on the provided object.

This function computes the ambient shape for a given object based on its properties, such as cutter restrictions and ambient behavior. It determines the appropriate radius and creates the ambient geometry either from the silhouette or as a polygon defined by the object’s minimum and maximum coordinates. If a limit curve is specified, it will also intersect the ambient shape with the limit polygon.

Parameters:

o (object) – An object containing properties that define the ambient behavior, cutter restrictions, and limit curve.

Returns:

The function updates the ambient property of the object in place.

Return type:

None

get_cutter_array(operation, pixsize)

Generate a cutter array based on the specified operation and pixel size.

This function calculates a 2D array representing the cutter shape based on the cutter type defined in the operation object. The cutter can be of various types such as ‘END’, ‘BALL’, ‘VCARVE’, ‘CYLCONE’, ‘BALLCONE’, or ‘CUSTOM’. The function uses geometric calculations to fill the array with appropriate values based on the cutter’s dimensions and properties.

Parameters:

• operation (object) – An object containing properties of the cutter, including cutter type, diameter, tip angle, and other relevant parameters.

• pixsize (float) – The size of each pixel in the generated cutter array.

Returns:

A 2D array filled with values representing the cutter shape.

Return type:

numpy.ndarray

check_min_z(o)

Check the minimum value based on the specified condition.

This function evaluates the ‘minz_from’ attribute of the input object ‘o’. If ‘minz_from’ is set to ‘MATERIAL’, it returns the value of ‘min.z’. Otherwise, it returns the value of ‘minz’.

Parameters:

o (object) – An object that has attributes ‘minz_from’, ‘min’, and ‘minz’.

Returns:

The minimum value, which can be either ‘o.min.z’ or ‘o.min_z’ depending

on the condition.

get_layers(operation, start_depth, end_depth)

Returns a list of layers bounded by start depth and end depth.

This function calculates the layers between the specified start and end depths based on the step down value defined in the operation. If the operation is set to use layers, it computes the number of layers by dividing the difference between start and end depths by the step down value. The function raises an exception if the start depth is lower than the end depth.

Parameters:

• operation (object) – An object that contains the properties use_layers, stepdown, and maxz which are used to determine how layers are generated.

• start_depth (float) – The starting depth for layer calculation.

• end_depth (float) – The ending depth for layer calculation.

Returns:

A list of layers, where each layer is represented as a list

containing the start and end depths of that layer.

Return type:

list

Raises:

CamException – If the start depth is lower than the end depth.

get_operation_axes(o)