When you release the left-mouse button at the required location, the snapped vertex moves to the closest projection of the target vertex on the modified surface. When you move the vertex, IDD automatically creates two-sided edges from its associated one-sided edges and bordering one-side edges of the neighboring or adjacent surface, if possible. This happens for each individual move; two-sided edges are created dynamically even before you exit the Move Vertex tool. To avoid this behavior, detach the surface before using the Move Vertex tool. You can then use unlimited drag and drop movements of the vertex to fine-tune the vertex’s placement before IDD attempts to create any new two-sided edges. The detached surface is moved to the top-level node in the Geometry and Topology Structure (GTS) Tree. Once the position of the vertex is finalized, cut and paste the surface back into the original component of the GTS Tree.