Given, the elevation and plan of a cube.

Locate the spectator point and the picture plane.

Join each of the corners in plan to SP, these lines are called lines of sight.

Insert ground line and horizon line, horizon line is the height of the spectator from the ground.

Where the lines of sight intersect the picture plane draw perpindicular lines to locate the corners in perspective.

Draw in the front face of the cube in perspective, taking the height from the elevation.

Locate the vanishing point by drawing a line from spectator point onto the horizon line.

Join the corners of the cube in perspective back to the vanishing point.

Where the lines of sight intersect the picture plane draw perpindicular lines to locate the corners in perspective.

Complete perspective projection by joining the corners together.