Weld Modifier
The Weld modifier looks for groups of vertices within a threshold and merges them, collapsing the surrounding geometry.
Options
The Weld modifier.
Mode
Method for choosing which vertices are merged.
All:
Merge includes all geometry including loose parts.
Connected:
Merge only includes attached geometry i.e. the modifier will not merge loose parts together.
Distance
Maximum distance that the vertices must have each other to be merged.
Only Loose Edges Connected Mode
Only collapse short edges which are not adjacent to any face. This is useful for example to stitch the seams used in cloth simulations.
Vertex Group
When the Vertex Group option is selected, only vertices with weight above zero will be affected by the modifier.
Invert
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Inverts the influence of the selected vertex group, meaning that the group now represents vertices that will not be merged by the modifier.
The setting reverses the weight values of the group.