Exercise 6 – Adding Section Fittings and Joints to the Equipment Support Structure
8.5 Modifying Panels
Having created a panel, the PLOO geometry may be modified by moving, adding and deleting vertices, edges and arcs. The vertices may also be expanded or contracted by a specified amount.
A group of vertices may be selected to be copied and inserted in a different part of the loop. Tools are provided to modify the group, e.g. move the origin or mirroring, before the group is inserted.
8.5.1 The Loop Vertex Editor form
With the panel to be modified as the CE, selecting
Modify > Extrusion/Panel… from the main menu displays the
Loop Vertex Editor form.
As with many of the forms used in PDMS, the Loop Vertex
Editor form fulfills several functions. The form is divided into
several areas which are described in the following sections.
8.5.1.1 Form Menus
The Loop Vertex Editor form menus contains the following options:
Control > CE - When the form is displayed, the CE name is displayed beneath the form menu.
Navigating to another panel and selecting this option makes the new CE the panel being edited by the form. The new CE name is displayed on the form.
Control > Close - This option dismisses the form.
Settings > Confirm - This is a toggle option. When set On the user must click the Create or Modify
button at the bottom of the form to implement each creation or modification, depending which mode is current. When set Off, each creation or modification is implemented immediately.
Settings > Confirm on delete – This is a toggle option. When set On, the user must confirm each deletion in order to complete the command. When set Off, deletions are implemented immediately.
Settings > Tag edges - This is a toggle option. When set On, each edge is tagged with the number of
the vertex at its start.
Edges are tagged automatically, regardless of this setting, if the panel has incorrect geometry for any reason (e.g. zero thickness). Settings > Free rotate - This is a toggle option. When set On this option allows groups of vertices to be
oriented automatically when they are positioned relative, to say one edge, and are then moved to a different edge.
Utilities > Remove Redundant - This option deletes redundant vertices in situations where two or more
8.5.1.2 Mode Selection
The options in the Mode Selection area of the form enable the user to select a single vertex, an edge or a group of vertices to be modified or create a new vertex.
Select all – allows the user to select all vertices in the loop allowing them to be modified as a group. Select group to modify – allows the user to select any number of individual vertices so they can be
modified as a group.
Select edge to modify – allows the user to pick an edge to be modified. The adjacent Edge gadget
shows the current edge number (i.e. the number of the vertex at its start).
Select point to modify – allows the user to pick a vertex to be modified. The adjacent Vertex gadget
shows the current vertex number.
Create points – allows the user to create a new vertex, which will be allocated the next number in the
sequence after the current vertex.
8.5.1.3 Vertex/Edge
The Vertex/Edge area of the form contains a Select button and a counter that shows the current vertex or edge, depending on the current mode. If the Select edge to modify button is clicked, the counter label will change to Edge and the counter will show the current edge.
The Select vertex/edge button allows the user pick a vertex in the 3D View. The adjacent Vertex/Edge counter shows the current vertex/edge number, which is also tagged in the 3D View.
The user can navigate to a specific vertex/edge by typing its number in the textbox or by using the up/down arrows to step through the list.
8.5.1.4 Group Definition
When a group of vertices are modified, the buttons in the Group area of the form become active. These options let the user modify the current group in the following ways.
These buttons affect only the Group’s behaviour; they do not affect the vertex numbering for the panel loop. A Group may be the entire loop if the Select all button has been used.Reverse group definition - reverses the group definition by implicitly re-numbering all of the
group vertices in the opposite sense (i.e., clockwise or anticlockwise). The origin moves to the other side of the ‘gap’. The sense of the current vertex sequence is shown by the aid arrow in the 3D View.
Move start forwards - moves the ‘open-side’ of the group, and the origin, one position
‘forwards’; that is, in the sense of the vertex numbering.
Move start backwards - moves the ‘open-side’ of the group, and the origin, one position
backwards; that is, in the opposite sense to the vertex numbering.
8.5.1.5 Group Expand/Contract
A Group may be expanded or contracted by the value specified in the textbox adjacent to the buttons.
Expand/Contract applies to all edges in the Group, including those on panel protrusions. Excessive expansion or contraction of Groups may lead to invalid loop geometry being created.8.5.1.6 Line
If an edge is modified, the buttons in the Line area of the form become active. These options enable the user to modify the current edge in the following ways.
Extend start of line - moves the Start vertex along the edge direction to align it through a
picked position. Use the Positioning Control options to pick the required position.
Alternatively, if a line is selected, the Start vertex will be moved along the edge direction until it intersects the picked line. These operations can change the edge length.
Extend end of line - moves the End vertex along the edge direction to align it through a
picked position. Use the Positioning Control options to pick the required position.
Alternatively, if a line is selected, the End vertex will be moved along the edge direction until it intersects the picked line. These operations can change the edge length.
Make line parallel - moves the free vertex (lowercase tagging) around the reference vertex to
align the edge with a picked line (another edge, a Pline etc.). This operation maintains the edge length.
8.5.1.7 Rotate
The options in the Rotate area of the form enable the user to rotate groups of vertices in the following ways.
Rotate anti-clockwise - rotates the edge anticlockwise, through the rotation angle specified in
the Angle textbox, about the reference end (uppercase tagging). This operation maintains the edge length.
Rotate clockwise - rotates the edge clockwise, through the rotation angle specified in the Angle textbox about the reference end (uppercase tagging). This operation maintains the
edge length.
8.5.1.8 Modify
The options in the Modify area of the form enable the user to carry out the following operations on the current Group selection.
Insert selected – enables the user to move a vertex group by inserting it at a different position
in the loop sequence. Use the Vertex selector to navigate to the required point in the sequence; the group will be inserted after the current vertex.
Mirror – enables the user to move the current vertex, edge or group such that the new positions are derived by reflecting the original positions about a picked line (an edge, Pline, etc.).
Delete selection – enables the user to delete a group, edge or vertex from the loop definition. Define/Modify arc – enables the user to manipulate a fillet arc at the current loop vertex.
When this button is selected the Modify Arc form will be displayed and the Loop Vertex
8.5.1.9 Aid Diameter
This section of the Loop Vertex Editor form allows users to control the size of the Aid Spheres displayed when modifying groups of vertices.
The sphere diameter may be entered in the Aid Diameter textbox. Alternatively, the up and down arrows adjacent to the textbox may be used. Using the arrows will increase or decrease the size of the aid spheres in 5mm increments.
8.5.1.10 Vertex/Edge/Group Coordinates
The bottom area of the Loop Vertex Editor form displays co-ordinate data about the current vertex, edge or group, depending on the Selection Mode, together with radius information where applicable.
For a vertex the X and Y (East and North) co-ordinates, with respect to the panel origin, are displayed. There is no Z co-ordinate as the panel loop is a 2D object. The Radius textbox allows the user to specify a radius to be applied to the loop at that vertex. This value is applied to the Fradius attribute of the vertex and may be positive or negative value.
A value of 0, the default, will produce a ‘sharp’ corner at the vertex.
A positive value will produce a convex radius at the vertex.
A negative value will produce a concave radius at the vertex.
For an edge the co-ordinates are given for the start or end of the edge. An aid is displayed in the 3D View showing which is the start and which is the end. By default the START of the edge, i.e. the vertex with the lowest number that forms the edge, is shown in uppercase and the end shown in lowercase. This means that any modifications made to the currently displayed co-ordinates will affect the START only.
The options list in this area of the form becomes active when an edge is selected and enables various options of how the edge is to behave to be selected.
Selecting the End option displays the END of the edge in uppercase and the start of the edge in lowercase. Modifications made will apply to the END of the edge only. It should be noted that modifying the length in
The Modify or Create button at the bottom of the form depend on the mode. In Modify mode clicking the button will change the current vertex or edge using the values in the X, Y, Radius or Length textboxes. In
Create mode, i.e. when adding a new vertex, clicking the button will create a new vertex with the values
displayed in the X, Y or Radius text-boxes.
8.5.2 Moving the Panel Origin
When creating a panel the Origin is placed at the first vertex by default and the X and Y co-ordinates of all other vertices in the panel relate to this position.
Selecting Position > Panel Origin from the main menu and selecting a different vertex when prompted enables the user to use a different vertex in the PLOO as the panel origin.
If the origin is redefined in this way, the coordinates of all vertices owned by the current panel loop are recalculated relative to the new origin such that their positions in the design model remain unchanged.
8.5.3 Modifying Panel Thickness
Although the panel thickness is set during creation it can be modified at any time.
Make the panel to be modified the CE and select Modify > Thickness… from the main menu to display the Panel Thickness form.
Entering a value in the textbox and clicking the Apply button modifies the panel thickness.
8.5.4 Modifying Panel Justification
Although the panel justification is set during panel creation it can be modified at any time.
Make the panel to be modified the CE and select Modify > Justification… from the main menu. This displays the Set Justification form.
Selecting Bottom, Centre or Top from the Justification list and clicking the Apply button modifies the panel justification. The In/Out checkbox enables the user to set the direction relative to the plane used to justify the panel as shown in the following diagram. In/Out justification is significant when Panel Fittings are considered.