Flex
The nodes that are to be flexed must be selected prior to opening this dialog box.
The flex operation moves a set of nodes, that are initially approximately in a line, into a specified shape. The shape can be linear, circular, elliptical or parabolic. The new position of one of the nodes is specified; this node is referred to as the shift node. A more complete description of the flex operation is given in the Flexing lines of nodes graphically section of the Working with GSA chapter.
Open this dialog box by giving the Sculpt > Flex line of nodes menu command when the current view is a Graphic view.
Flex line of nodes is also available on the right-click menu that is displayed when the cursor mode is set to Select nodes. Invoking Flex via the Sculpt > Flex line of nodes menu command assumes the middle node as the node to be explicitly shifted; Flex via the right-click menu requires that a node has been right-clicked and this node is assumed as the shift node. Either way the shift node can be re-selected from within the Flex dialog box.
Axes
Opens the Axes dialog box. The shift coordinates are expressed with respect to the current axes. Axes default to the axis set defined for the current grid (not adjusted by the grid plane elevation).
Shift node
The node that is shifted to the shift coordinates. The shift node must be one of the current selection of nodes. Nodes at the ends of the line of nodes may be selected as the shift node only when flexing linearly.
Note: The current shift node is highlighted on the Graphic view.
Shift coordinates
The shift coordinates specify the new position of the shift node. Note that Shift By vector specifies a shift relative to the initial position and Shift to position is an absolute position. In both cases the coordinates are with respect to the defined axes for the flex. Note also the special case of a circular flex with specified radius, described below.
Flex shape
The flex may be specified in one of the following ways:
- Linear: The nodes are arranged linearly between the end nodes and the shift node. The shift node may be an end node. Shifting an internal node results in two lines of nodes meeting at the shift node. This option may be used to align or evenly distribute a set of nodes.
- Circular: The nodes are arranged on a circular arc that goes through the end points and the new position of the shift node.
- Elliptical: The nodes are arranged on an ellipse or a sheared-ellipse that goes through the end points and the new position of the shift node. If the shift node is shifted normal to the line between the end nodes then a true ellipse is formed. If the shift node is also shifted parallel to the line then the ellipse is sheared to result in the shift node being positioned at its shift coordinates.
- Parabolic: The nodes are arranged on a parabola or a sheared-parabola that goes through the end points and the new position of the shift node. If the shift node is shifted normal to the line between the end nodes then a true parabola is formed. If the shift node is also shifted parallel to the line then the parabola is sheared to result in the shift node being positioned at its shift coordinates.
When the flex shape is set to circular the circle radius may be specified. Note that when the circle radius is specified the shifted position of the shift node is used only to indicate the general direction of the flex; the shift node is shifted onto the circle defined by the end points and radius (which is not necessarily the specified shift position).
Spacing of nodes
The spacing of nodes can be one of the following:
- Space evenly: The nodes are spaced evenly between the end nodes and the shift node.
- Space proportionally: The spacing of the nodes between the end nodes and the shift node remain at the same proportion as their initial spacing along the line of nodes.
This spacing is only true for linear and circular flexes. Elliptical and parabolic flexes use this spacing to distribute the nodes along the line of nodes before projecting them onto the ellipse or parabola. So, for elliptical and parabolic flexes, the spacing is a basis for the final positioning of the nodes, not an actual spacing.
Coincident nodes: Use existing nodes where present
When checked, wherever a flexed node is shifted to within the coincidence tolerance of an existing node the flexed node is replaced by the existing node. Otherwise the flexed node is always retained even when it is coincident with another node.
Preview
Display the consequences of this operation in the current Graphic view without committing to applying the operation. Exiting this dialog box by Cancel will undo the preview.