Lets you merge edges to create a shared edge between them by selecting the two edges. The options determine the merge behavior.
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A new edge is created equidistant between the first and the second edges you select. The first and second edges you select
are removed. This is the default setting.
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The first edge you select becomes the new edge and the second edge you select is removed.
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The second edge you select becomes the new edge and the first edge you select is removed.