Mesh Topology Mapping Attributes Add on + Topological Symmetry and Topology Blend Geometry Nodes For Blender

This add on for Blender creates mesh INT attributes in the point domain to either find topological matching on two meshes with identical topology but different vertex order, or to map topological symmetry on the selected mesh.
It works in conjunction with three Geometry nodes modifiers:
Topological Symmetry Modifier
Topology Blend Modifier
Vertex Reorder

To Install:

• Download the file TopologyMappingAttributes Add on v.1.1.zip.
• In Blender, under Edit>Preference navigate to the Add-ons tab and from the pop up menu on the upper right side of the panel select "Install from Disk "

• Navigate to the location where the Zip File has been downloaded, select and "Install from Disk"
• If the add on has been installed correctly the user should see this.
  

How to use:

Make sure Blender is in edit mode with at least one mesh selected.
From the Mesh menu select "Create Topology Mapping Attributes"
The tool will prompt to highlight two faces and two edges.
Right click will lock the Face Selection.
Left click will release the Face Selection.
Enter it will create the topology attributes.
Esc will cancel the operation.

• To Create Topological Symmetry mapping:
  Make sure the user selects two matching faces, possibly the one that share the middle edge
  
  
  If there is no middle edge or the user wants to match two different elements in the same mesh it is important that the highlighted edges are specular to the mirror axis.
  
  
  
  
  Once Enter is pressed an attribute named "symmetry_indices" will be created
  
  The attribute holds the the opposite matched vertex index for each vertex that has been tracked. The untracked vertices will hold a -1 value.
  
  
  To track the untracked vertices just repeat the same operation on the other elements.
  If the user tries to track an element that has been already tracked all the other elements will be set to -1 and will need to be tracked again.
• To find topological matching between two meshes with different vertex order:
  
  Different vertex index
  With both objects selected in Edit Mode just highlight two matching faces and two matching edges and press Enter.
  This will create mesh attribute named "sorted_indices_from_face".
  Both meshes will hold the vertex ordering of the other mesh
  
  

Geometry Nodes

Installation:

• Download topological_mapping_nodes.blend copy the file in of the folders of the asset library. The path to the asset libraries can be found under Edit>Preferences File Paths Tab
  The user should be able to see 3 new items in the Asset Browser under the unassigned category
  Topological Symmetry Modifier
  Topological Symmetry Node (This node is a component of the Symmetry modifier)
  Topology Blend Modifier
  Vertex Reorder

• To use the Topological Symmetry modifier:
  Once created the symmetry_indices attributes just drag the modifier on the mesh.
  The mesh already appear symmetrize but there are few options we can tweak:
  
  Action:
  Blend: will mirror the one side over the other and vice versa if flip Axis is checked. This is the only action that supports the Seam option.
  Flip: Will flip the mesh overt
  Symmetrize: Will average the position of the vertices on both sides/
  
  Axis: The axis where we want to mirror the mesh.
  
  Factor: Is the amount of transformation of the vertices
  
  Smooth Seam/Smooth Iterations : This works with the Iterations and it will blur the seam for the number of iterations
  Seam Spread will set the width of the grey point in the middle.
  
  Vertex Group: filter the deformation through a vertex group (if there is a float value in the field, just enable the Input attribute toggle on the side of the field)
  
  
• To use the Topology Blend Modifier:
  Once created the sorted_indices_from_face attribute on the meshes just drag the Topology Blend Modifier on the mesh the user wants to being driven by the other mesh.
  
  Us the picker or select from the list the other mesh and use the factor to set the blending factor between the two meshes.
  

• To use the Vertex Reorder:
  Once create the sorted_indices_from_face attribute drag the Vertex Reorder modifier on the mesh that needs vertex reordering and apply the modifier.