Slicing: Create a Slice
Time to read: ~6 min
Generating a new slice consists of simply defining a plane that intersects the data of interest. If multiple bodies are present and the data is to be kept separate, the bodies first need to be Split.
The sections below describe the available options and tools:
The first step is to generate a new slice of the data. This button will start the process and will open up a new dialog page for the surface/plane definition:
The definition of the plane allows for several options with a number of sub-options. The following definitions are available:
- From Surface
- This allows an existing surface (triangle) to be selected and used as a reference. If no additional location is chosen, the plane will coincide with the triangle. Additionally, it is possible to define an offset distance or to provide a point through which the plane is to pass (parallel to the original surface).
Definition of the point can be done either by directly picking one (cursor button) or through the more advanced point selection dialog with its own set of options.
- At Angle
- The option to define a plane at an angle to an existing plane is offered with this option. Here a reference surface is defined as well as an axis to rotate around together with an angle (in degrees).
if the axis lies in the same plane as the surface, it is rotated around this axis (can be an edge or defined with the more advanced edge selection dialog). If the axis does not lie in the plane, it is rotated with the offset distance maintained.
- Through Points
- This is the most direct option for cases where there is no clear reference geometry to follow. The definition is based on the use of three points and optionally an offset or offset point.
- Through Edges
- The option to define the plane by means of edges allows for cases where edges are available that define the general layout. If the edges do not lie in a plane, the general direction obtained from them is used. Parallel edges can be used as well as edges that intersect.
- This defines a plane through an equation of the form Ax+By+Cz+D=0. No additional options are available for this definition.
- Coordinate Planes
- One of the three coordinate planes (X-Y, Y-Z and X-Z) can be used to define the base orientation and then (optionally) an offset of point is used to define where the plane is to pass through.
With most of these construction methods, it is possible to use the more detailed construction dialog to define points or edges. For points, it is possible to define the center of an arc by selecting one or more edges along the arc perimeter.
The Slice-Edit option allows for the plane to be redefined. The same general workflow as for the New Slice option is applicable.
All slice data is considered part of the data to generate/export. If data is not desired, it can be deleted.
Note: a specific slice can also be selected from the Tree View on the left and using a Right-Click selected for deletion.
If a Body is selected, all slices under it can be deleted in one step.
Load Slice Definitions
Slice Definitions can be stored and re-used across different files. To import a previously generated slice definition, the Load dialog box brings up files matching the InStep Slice File format.
Save Slice Definitions
The Save button allows the current Slice definitions to be saved to a file. This applies to the definition of the planes, not the actual intersection data formed when a slice is applied to a body.
Convert Slices to Polygons
Depending on the workflow intended, it may be beneficial to convert the slice definitions to a set of surface polygons rather than to directly export them. This may be the case if the surface data contains faults or needs to be refined or used for other purposes. Using the Convert to Polygons options generates new Bodies from the slices.
There are a few settings that are specific to the Slicing options and determine how different aspects will behave. More information on these settings is available from the Settings Page
Delay Surface Creation
In general, the application will generate intersection data (line segments where the plane intersects the bodies' surfaces) as soon as the plane has been generated. This process is relatively fast and should not cause any major delay for moderately sized bodies (less than about 100k facets).
If the generated segments are then to be written to DXF files, no further processing of the data is required. However, if the data is to be converted to STEP (or Polygon) data, then some additional processing is required such as determination of interior/exterior regions and tessellation of the boundary points.
Especially the tessellation process can take some time and may lead to incorrect surface data if the boundary contains faults. Selecting the Delay option, skips the surface generation when a slice has been defined until either the data is exported to a format that requires it or until the checkbox is
unchecked and the corresponding surface double-clicked which causes the data to regenerate.
Tree View Interaction
Each item in the tree has some direct functionality that can be accessed by clicking on it and expanding to the relevant item and performing a Right-Mouse click.
At the body level, all dependent slices can be deleted by using the 'Delete All' option (this does not affect the body itself, only the slices that depend on it).
On the Slice level, there is the option to Delete the slice, Rename it (name only applies to DXF data), or to create Duplicates of the slice. The Duplicate option prompts for the number of slices to generate and the offset from each other. The offset is applied along the plane normal in the current work-units.
At the Surface level, individual surfaces can be deleted which can be useful if the Surface Creation process found separate surfaces (only generated if the Surface Creation has not been delayed).