Description

The Tweak command allows you to individually move the grid points of a selected connector, domain, or block in order to locally improve the quality of a handful of cells. This feature is a good complement to Pointwise’s current suite of grid solvers. While a solver generally affects all of the cells in a grid, Tweak allows you to modify a single cell to meet specific requirements.

 

Note: For a prism block, the K cutting planes are available in addition to the XYZ cutting planes in the Tweak command. This allows you to tweak a grid point on a specific grid layer in the marching direction.

For editing interior points of an entity, select the entity then Edit, Tweak. The Tweak panel provides different options based on whether a connector, a domain, or a block entity is selected (see figures below).

Tweak Panel
Use the Tweak command to edit the interior grid points of connector.
Tweak Panel 2
Use the Tweak command to edit the interior grid points of domains.

For tweaking grid points on a connector or inside of a domain, move the cursor over a target grid point in the Display window and relocate it by one of two methods:

  • Left-click on the grid point and drag it to a new location.
  • Hold down the Ctrl key and left-click the grid point. Once selected, enter the new XYZ coordinates in the Point Placement frame, or XYZ Offset or Normal Offset (UV and UV Offset if database constrained) in the Point Placement, Advanced frame. All the Point Placement commands are already described in detail in the Point Placement section.

Note that the boundary of the underlying database entity will be highlighted if a selected point is database constrained. If the new location is not satisfactory, use the Restore command within the Points frame to move the grid point back to its original location.

Tweak Connector
An existing grid point on a selected connector will appear as a yellow square within a circle while cursored over.
 An existing grid point inside a selected domain will appear as a yellow square within a circle while cursored over.
An existing grid point inside a selected domain will appear as a yellow square within a circle while cursored over.

When a block is selected for tweaking, a cutting plane is rendered at a default location. This cutting plane has a green border frame and semi opaque shaded interior making it easier to visualize exactly where the cutting plane intersects the model. Note that the frame of the cutting plane can be clicked (this highlights it) and dragged to a new position directly in the Display window.

Tweak Cutting Plane
A cutting plane appears for blocks that allows the grid points on this plane to be selected and edited.

Additionally, the position of the cutting plane can be specified via either an XYZ or IJK location, or by using the left and right arrow buttons in the Cutting frame. The options within the Cutting frame are described in the Cuts Tab section. Once a cutting plane has been specified, use either one of the methods mentioned above to select and move a non-boundary grid point.

By default, the movement of a grid point being dragged to a new position is constrained to a plane that is parallel to the current view plane. Therefore, a tweaked point will be contained on its cutting plane only in the special case when both, the cutting and current view planes, are parallel. On the other hand, a cutting plane whose orientation is not parallel to the current view plane, will not contain any of its tweaked points.

A tweaked point will be contained on its cutting plane only in the special case when both, the cutting and current view planes, are parallel.
A cutting plane whose orientation is not parallel to the current view plane will not contain any of its tweaked points.
Tweak Panel Block
Use the Tweak command to edit interior grid points of a selected block.

The Options frame offers additional control over the destination of a selected grid point.

  • Unconstrain from Database allows a database constrained grid point to be moved to a new location off the database entity it used to be associated with. This command is only enabled when you hold down the Ctrl key and left-click a grid point. By default, it is disabled such that database associativity will always be maintained during tweaking.
  • Maintain Connector Shape if checked, restricts the point movement such that the original connector shape will be maintained. This command is only available for tweaking connector grid points.
  • Snap to Points if checked, allows you to move a selected grid point precisely to the location of an existing grid point in your grid.
  • Move Rotation Point Automatically if checked, updates the location of the rotation point automatically as a selected point moves.

For more details on the commands inside the Display frame (see figure above), please refer to the Attributes section.

You can continue to select another grid point for modification without leaving the Tweak panel. Click OK to save the new grid and exit the command panel, or click Apply to save your changes and continue modifying your grid. Otherwise, click Cancel to exit the Tweak panel without saving any changes.

Keep in mind that you will need to use the Examine command to diagnose your new grid resulting from the tweak of grid points.