Merges selected edges and vertices that are within a numerically specified threshold distance of each other. For example,
            two selected edges will be merged into one shared edge.
         
         
          
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            Note 
                  The contents of the Merge option window changes depending on the current selection type. That is, some options are only available
                     when either edges or vertices are selected. When no valid selection occurs the merge vertex options appear. The differences
                     are noted below.
                  
 
                
             
                 (for edges)
               
 
                These options are available for Merge when edges are selected.
               
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                        Merges the UVs shared by the edges. If turned off, the UVs are not merged and can be manipulated and edited independent of
                           each other. The default setting is on. This option is available only when edges are selected.
                         Tip 
                              If you have a model that is mapped with different textures on either side of where the edges merge, it is a good idea to turn
                                 this option off.
                               
 
 
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                        Any selected edges further apart than this distance will not be merged. Set this value carefully. If it’s too small, no edges
                           will merge. If it’s too large, the operation may merge unwanted selected edges. The default is 0.01.
                         
 
  
                  
                  Determines the threshold distance between edges in different coordinate systems.
                  
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                            Specifies that the Threshold value is the distance between edges in world space. This is the default.
                            
 
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- 
                         
                           Specifies that the Threshold value is the distance between edges in local space.
                            
 
  
             
                 (for vertices)
               
 
               These options are available for  when vertices are selected.
               
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- 
                      
                        Any selected vertices further apart than this distance will not be merged. Set this value carefully. If it’s too small, no
                           vertices will merge. If it’s too large, the operation may merge unwanted selected vertices. The default is 0.01.
                         
 
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                        When two vertices are selected, the  feature will merge them regardless of the Threshold value. This option is available only when vertices are selected.