Once the splines have been created and edited the user is able to generate a grid. At this stage the Create Grid button is available to be selected as shown in Figure 1.
Figure 1 Grid menu before creating a grid.
The number of cells must be specified by the user after clicking the Create Grid button. After a grid has been created the whole grid menu is available to the user and is made up of eight buttons as shown in Figure 2.
Figure 2 Grid menu.
This menu is used to create and edit grids in the workspace. The user has various options when deleting nodes as in the drop down menu as shown in Figure 3 and Figure 4. Table 1 provides further detail on each of the Grid menu buttons.
Figure 3 Insert cell icon options.
Figure 4 Delete cells icon options.
Hint: before creating a grid make sure that the splines are drawn correctly and are in the best position to create a very orthogonal grid.
Table 1 Grid menu button details.
This button will generate a grid within the area enclosed by the splines. The number of cells in the I and J direction will depend on the user's input in the Operations toolbox.
This button allows the user to insert one or multiple cells within the generated grid. There two options in the drop down menu as shown in Figure 3.
Insert a Cell will add one cell at a time to the generated grid. To add a cell, click just outside the grid where the extra cell is desired. The new cell will be added and connected to the nearest cell(s).
Insert a Multiple Cells will add a number of cells to the generated grid by selecting two nodes on same marginal grid line. The new cells will be added and connected to the nearest cell(s).
This button allows the user to delete one or multiple cells within the generated grid. There are a number of options in the drop down menu as shown in Figure 4.
Delete a Grid Node will immediately delete the node of a cell selected by the hand icon.
Delete Nodes Inside a Polygon allows the user to create a polygon with LMC. Closing the polygon with a RMC will delete multiple cells inside the polygon.
Delete Nodes Inside a Block is used by clicking two nodes to indicate the corners of the grid block that you want to delete. A block is selected which just contains the selected nodes. Clicking the second node will delete all cells of the block area.
Delete Nodes Outside a Block is used by clicking four nodes to indicate the corners of the grid block. A block is selected which just contains the selected nodes. Clicking the fourth node will delete all cells in the area outside the selected block.
Deactivate Line of Cells: Instead of deactivating cell by cell on the grid, select this function then draw a line by LMC in order to intersect multiple cells. RMC to end the line and multiple cells along that line will be deactivated.
This button will move nodes on a grid. To move a node on the grid, LMC on the desired node then LMC on the position it should be moved to. Any line connected to that node will move also.
Delete the entire grid selected. Simply click this icon and then select the grid to delete. Note: any grid connected separately to the grid selected will also be deleted.
Select a grid so that it can be edited. If there are several grids in the workspace that are not connected the user will only be able to edit one at a time. This icon selects a grid and makes it active for editing.
Go back to a previous operation (Undo).
Go forward to next operation.