You will need
  • Image details without some visibility at least in two main types, exciting the front view, it is better suited top and front views, marked key points in the drawing, in which visibility is determined.
Locate the drawing point, the projection of which on any plane are the same, not coinciding at the same time on the other plane of projection. Such points are called rival and they will be used as reference points in the construction of appearances, telling us information about the location in space of the objects to which these points are linked.
Using you noted earlier point to determine visibility, direct swipe so that they were perpendicular to one of principal planes of projections, while automatically becoming parallel to the other plane of projection.
Mark the points of intersection of lines in the previous step, with the detail. These points are competing, since their projections on the same plane will be the same, not coinciding at the same time on another plane. If the projection points coincide in the frontal plane (P1), such points are called front competing. If the projection points coincide on a horizontal plane (P2), these points are called horizontal competing.
Determine visibility. For front competing points visibility is determined from the top view. The point the horizontal projection of which is located lower, i.e. closer to the observer, is visible in the front view. Accordingly another point, contending this will be invisible. For horizontally competing points of visibility is determined on the front view, while the dot is visible which is above the rest, and everyone else competing this will not be visible.