# Local Domains Morphing

You can change the shape of a model with local domains and handles.

Morphing can be accomplished using one or more of the following methods:
• Moving the local handles
• Changing a distance or angle
• Changing the radius, curvature, or arc angle of an edge domain
• Mapping nodes to a line, plane, surface, or mesh
• Using section mapping, line and surface difference, and element offset
• Using freehand morphing capabilities such as move nodes, record, and sculpting
You can move handles in the Morph panel, Move Handles subpanel using the following options:
interactive
Move handles interactively by dragging the mouse across the screen. You select an entity such as a vector, line, plane, surface, or domains, to orient the mouse location in 3D space, and move a handle by clicking on it and dragging it to a new location. Interactive morphing is most effective for visualizing how the mesh will react when a handle is moved and for making approximate shape changes. If you want to move a handle a specific distance or to a specific position, it is better to use a non-interactive option.
translate
Translate handles along a vector or element normals.
rotate
move to XYZ
Position handles at specific XYZ locations or place them on lines, surfaces, or another mesh.
move to node, move to point
Position handles at specific node or point locations, or place them on lines, surfaces, or another mesh.
When applying handle perturbations to your model, it is important to note that the nodes in the model follow the movements of the handles according to the influence coefficients. This concept comes into play when you are using the rotate function. After rotating handles you may find areas in the model, particularly those defined by curved edges, that are not rotated the same as the neighboring handles. This is because the nodes have followed the handles instead of being rotated about the axis. To correct this situation, select the true rotation checkbox. This will cause the nodes to be rotated as well as the handles with the amount of rotation being equal to the influence coefficient. Although it could be argued that true rotation is the "correct" way to morph via rotation of the handles, not all morphing applications are best done using true rotation.

While morphing a model, the following message may be displayed: "Some handles selected are dependent on others. Would you like to ignore dependencies for this operation?". This occurs when both a dependent handle and the handle on which it is dependent are selected to be morphed. If you click yes the given perturbation is applied to each handle and the dependent handles are not given an additional perturbation inherited from another handle. If you click no, the given perturbation and any inherited perturbation is applied to each dependent node. For most cases you will want to click yes.

The Morph panel, Alter Dimensions subpanel allows you to change one of the parameters in the model, such as the distance between nodes, the angle between nodes, or the radius or curvature of an edge domain. The basic concept is as follows:
• Select two nodes (node a and node b).
• Select handles corresponding to those nodes.
The handles selected are the ones that will move to make the distance between node a and node b, or angle with a vertex selected, equal the specified value. You must select at least one handle for each end and the handle may be coincident with one of the nodes. For solid models, controlling a particular dimension often involves moving more than one handle for each end.
The radius, curvature, and arc angle options are used as follows. You select any number of curved edge or 2D domains, select the center calculation and style options, set the new radius, curvature multiplication, or arc angle factor for them, and click morph. All the domains are changed simultaneously.
Note: The curvature tool scales your radius by a factor rather than a set radius, so if you want to change a radius from 5.0 to 8.0, you need to set the curve ratio to 1.6. The curvature tool is intended for domains that do not have constant curvature. Making the bias factor retroactive does not work for radius changes.
Methods available for calculating the center of curvature for the selected domains include:
by normals (Default)
Uses the element normals to approximate where the center of curvature is for each node in the selected domains. This method is not always accurate, but often gives good results for regular meshes.
by axis
you may select an axis which will serve as the center of curvature.
by line
You may select a line which will serve as the center of curvature.
by node
You may select a node which will serve as the center of curvature.
by edges
Uses the edge domains to calculate the center of curvature with the center lying in the plane of the edge domains. The symmetry option refers to how the morphing of the edge domains is applied to neighboring 2D domains. The auto-symmetry option was the default for HyperMorph prior to version 8.0. In 8.0 you may choose to turn off symmetry when using this option.

For auto-symmetry, the changes in the radii of the edge domains are applied to any 2D domain, depending on the number of edge domains you change for the 2D domains. If you change only one edge domain for a given 2D domain, the radius change will not be applied linearly across the 2D domain. If you change the radii of two edges for any given 2D domain, either a linear or planar temporary symmetry is created between the two edge domains for the 2D domain that will apply radius changes more linearly across the 2D domain. This works best if the mesh is regular. If you are changing only one edge for a 2D domain, you can increase the bias factor of any handles on an edge domain to yield a more even distribution.

Mapping an edge domain to a line or a 2D mesh to a plane, surface, or mesh is done using the Map to Geom panel. This option is very effective for fitting a mesh to new geometric data. When mapping a domain to a geometric feature, all the nodes in neighboring domains are stretched along with it, minimizing mesh distortion. You have several options for determining how the nodes for the mapped domain are placed on the geometry. When mapping an edge domain or node list the nodes can be moved normal to the line, along a vector to the line, or distributed along the full length of the line. When mapping a 2D domain or selection of nodes to a plane, surface, or mesh, the nodes can be moved normal to the target, normal to the elements of the 2D domain or selected nodes, or along a vector. If you wish to fit a mesh to a surface, there is no option to do this automatically, however, with multiple mapping operations, or using the user control option you can fit a 2D domain to a surface.

Furthermore, you have the option of creating a morph constraint between the nodes and the map target automatically after mapping. This constraint will allow you to do further morphing operations while maintaining the constrained nodes on the geometry.

The map to geom panel is also effective for solid model meshing. You can create a block of solid elements roughly in the shape of the geometry that you are trying to mesh, and then use map to surface to morph the faces of the block to the geometry.