# Alter Dimensions

Morph a mesh by selecting a dimension in the model and change its values.

There are five dimensional types that can be altered: distance, angle, radius, curve ratio, and arc angle.

For distance and angle, you define the dimensions by selecting domains, nodes and/or handles that will be used to alter the dimension.

For radius, curve ratio, and arc angle you select one or more curved edge or 2D domains whose radii or curvature you wish to change.
Note: The curve ratio tool scales your radius by a factor rather than a set radius. If you want to change a radius from 5.0 to 8.0, you need to set the curve ratio to 1.6. If the domains that you want to morph do not have constant curvature, the curvature tool will maintain the curvature variations while scaling the local radii.

If you have any reflective symmetries (1-plane, 2-plane, 3-plane, and cyclical) in the model, the changes applied to any domains assigned to those symmetries will automatically be reflected to all linked domains.

Figure 1 shows morphing by altering a distance using two handles. Handles a and b are selected, and the distance d between them is calculated and displays in the distance= field. By changing this value and clicking Morph, the distance between the handles can be set to a new value. Figure 2 shows morphing by altering a distance using the nodes and handles option. The green circle marks end a and the blue circle marks end b. The original distance "d" is 23. Three handles are selected as followers for end a and two are selected as followers for end b (upper left picture). The distance is changed to 15 and the morph button is clicked. If hold end a is selected, the handles move in such a way such that only node b will move to make the new distance 15 (upper right picture). You can also choose hold end b (lower left picture) or hold center (lower right picture).
Figure 3 shows morphing by altering an angle using the nodes and handles option. The green circle marks end a, the red circle marks end b, and the blue circle marks the angle vertex (left). The original angle "theta" is 90 degrees. One handle is selected for each end. In this case since the handles are coincident with the nodes at end a and end b, the two handles or edge domains options could have been used instead. The value in the angle window is changed to 45 degrees, the hold middle option is selected, and the morph button is clicked. The handles are moved in such a way that the new angle between the selected nodes becomes 45 degrees. Alter angle also has the hold end a and hold end b options.
Note: If the red and green nodes do not have coincident follower handles, HyperMesh iterates until the angle is either within one one-thousandth of a degree of the target or it has converged as close as possible.
Radius, curvature, and arc angle allow you to select one or more edge domains (and any associated 2D domains) and adjust their radius, curvature, or arc angle. Radius and arc angle are intended to be used with domains of constant curvature. Curvature is intended to be used with domains of changing curvature or with multiple domains with different radii. Curvature will change the radius along the length of the curve by multiplying it by the given ratio. The hold options for radius and curvature determine whether the ends move towards or away from the center (hold center), tangentially (fillet), stay fixed (hold ends), or move towards one end (hold end). For the hold end option you should select all of the nodes for the held end or ends.
Figure 4 shows morphing by radius using the fillet option and the options by edges and auto-symmetry. The two edge domains are selected and both have a radius of 5. The radius is changed to 3 and the morph button is clicked. The ends of the edge move tangentially to keep the angle constant. This option is very useful for changing fillets. The radius change of the 2D domain is not as smooth as the radius change for the edge domains. To better change the radii of the 2D domain for this example the center calculation method should be switched to by normals and the 2D domain should be selected along with the two edge domains. If the result is not accurate enough, which can often be the case when the mesh is not perfectly curved, try creating a line through the center of curvature and using the by line option.
Note: For the by line option, the line will only be at the center of curvature for the first morph unless you are using the hold center option.
1. From the Morph ribbon, click the arrow next to the Morph tool set name and select Alter Dimensions.
2. In the Morph: Alter Dimensions dialog, define parameters.
Parameter Action
Dimension Choose the type of dimension that you wish to alter.
Distance
Distance between two nodes.
Angle
Angle made by two nodes and a vertex.
Radius of an edge domain and associated 2D domain.
Curve Ratio
Curvature of an edge domain and associated 2D domain.
Arc Angle
Length of an edge domain and associated 2D domains about an axis, as determined by degrees.
For example, a semi-circular curved surface would have an arc angle of 180 degrees; changing it to 90 degrees would make the surface encompass only a quarter-circle instead of a half-circle.
For example, a semi-circular curved surface would have an arc angle of 180 degrees; changing it to 90 degrees would make the surface encompass only a quarter-circle instead of a half-circle.
Measure Between Choose the type of entities to use.
Two Handles
One handle will be end a and the other will be end b. Once selected, the distance between them displays in the distance = field.
When morphing by angle, this option also requires you to select a vertex to define the angle (in conjunction with end a and end b).
Edge Domain Ends
The handles at the ends of the selected edge domain will be used for end a and end b and moved toward or away from each other to change the distance between them.
Two Nodes
End a and end b may be located at nodes other than where handles are and that "follower" handles for each end will be moved as groups towards or away from each other to change the distance between the two nodes.
Restriction: This option is only available when morphing by distance.
Measure Using Choose the orientation of the angle normal to an existing entity or direction.
Three Nodes
Use any of the global axes (x, y, or z) to morph in a plane that is normal to that axis.
Two Edge Domains
Use the plane normal to any two other nodes which you have selected.
Two Handles and a Vertex
Use the plane formed by end a, end b, and the vertex node.
Restriction: This option is only available when morphing by angle.
End A Specify one end of the relevant distance. Depending on the setting of the entities to use switch, this will require you to select a handle, node, or node a.
Restriction: Only available when morphing by distance or angle.
Followers (End A) The selected follower handles will move as end a moves.
Restriction: Only available when morphing by distance and measuring between two nodes or by angle and measuring between three nodes.
End B Specify one end of the relevant distance or angle. Depending on the setting of the entities to use switch, this will require you to select a handle or node b.
Restriction: Only available when morphing by distance and two handles or nodes and handles, or by angle and nodes and handles.
Followers (End B) The selected follower handles will move as end b moves.
Restriction: Only available when morphing by distance and measuring between two nodes or by angle and measuring between three nodes.
Restriction: This option is only available when morphing by radius or arc angle.
Edge and 2D Select one or more edge and 2D domains. For every 2D domain you must select at least one edge domain which touches it. The average radius of the selected domains automatically appears in the radius = input.
Restriction: Only available when morphing by radius, curve ratio, or arc angle.
Center Calculation Choose a method of center calculation.
By Axis
Select an axis to be the center of curvature for the selected domains.
By Edges
Use the plane of the edge domains and curvature from node to node to calculate the center. Also, you have the option of letting HyperMorph automatically create a symmetry on 2D domains for which two edge domains have been selected, which generally makes the dimension alteration smoother across the 2D domains if the mesh is regular.
Note: Only available for edge domains.
By Line
Select a line to be the center of curvature for the selected domains, then choose project normal or project direct from the toggle. This toggle determines the direction which the nodes will be projected towards the line when determining the center for each node.
By Node
Select a node to be the center of curvature for the selected domains.
By Normals
Use the normal vectors for the elements on 2D domains and the selected edge domains to interpolate the center of curvature for each node.
This method can be imprecise due the fact that element normals do not always point exactly towards the center of curvature.
Restriction: Only available when morphing by radius, curve ratio, or arc angle.
Hold Choose which portion of the line between the selected ends remains fixed, and therefore determines which of the two ends moves.
Restriction: For morphing by radius, curve ratio, or arc angle:
Choose how the center of the radius is treated with respect to movement during the morph.
hold center
Keep the center in place, moving both ends of the radial curve equally.
fillet
Change the radius and move the center as necessary to keep the radial curve tangent to its surrounding mesh.
hold ends
Keep both ends of the radial curve in place, effectively moving its center. This means that as the radius increases, the curve between the ends becomes flatter.
hold end
Select the node at one end of the curve that you wish to keep steady. The other end of the curve and the center will move when morphed.
Force Edges Circular Force the selected edge domains to be circular after morphing.
Restriction: Only available when morphing by radius, curve ratio, or arc angle.
Force Edges Flat Project the nodes of selected edge domains to a plane prior to morphing.
Restriction: Only available when morphing by radius, curve ratio, or arc angle.
3. Click Morph.