Repositioning polygon components in the perspective view can be more challenging when compared to the orthographic views because your frame of reference changes as you track, dolly, or tumble the 3D view.

By default, the Move Tool lets you reposition components in relation to world space coordinates. That is, the movement of a component is referenced to a direction based on the center of the 3D scene and the X, Y, or Z axes.

It is also possible to set the Move Tool to move objects and components based on other coordinate systems, such as object space and local space.

In addition, you can also move a polygon component in relation to its surrounding mesh. For example, you can select and move a vertex in a direction that is perpendicular or normal to its surrounding surface mesh. This is a useful technique for correcting any protruding vertices on the mesh.

To move a vertex on the mesh in a direction normal to the mesh

1. Dolly and tumble the perspective view while examining the mesh until you find vertices that protrude outwards from the mesh in an unwanted fashion.

   

2. In the Toolbox, double-click the Move Tool to display the Move Settings editor.
3. In the Move Settings editor, in the Move section, turn on the Normal option.

   

4. In the perspective view, click the vertex you wish to reposition.

   The vertex highlights and the Move manipulator appears to indicate the three directions of movement that are possible in this mode.

   

   The U and V handles slide the vertex in relation to its associated edges, while the N handle moves the vertex either away or towards the mesh depending on the direction you move your mouse.

5. Drag the N handle outwards or inwards depending on what’s required for that particular vertex. Dolly or tumble the view as required to examine the mesh after you’ve done this and make any modifications as necessary.
6. Repeat the above steps for any other protruding or receding vertices on the mesh until you are satisfied that the mesh appears smooth.
7. Before you proceed to the next section, double-click on the Move Tool and return the Move setting to the default World setting.

If you examine your model in the perspective view your helmet mesh should now match the reference sketches as they appear in both the front and side image planes (see image below). The mesh should also have a relatively uniform distribution of polygon faces on the mesh and the edge loops should flow smoothly.