**The square-grid **

Figure 1 shows the plan of a building in x,y-map-presentation, and the
projection of this building onto a Picture Plane (PP) vertical to the
Ground Plane (GP). |
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How to create : | ||

1. : Draw a line f through Z parallel to a to create P
as crossing-point with PL [the line marking the intersection of the
Picture Plan (PP) with the Ground Plane (GP)], draw a vertical
line to PL through P to create VP1 on the Horizontal Line (HL).
Do correspondingly to create VP2. |
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2. : Draw lines from Z through the corner points of the building to
create corresponding crossing-points with PL, draw vertical lines to
PL through these points to create the lines defining the walls of the
building. |
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3: Choose C and h * and draw the outlay of the building. (* C
and h are frequently set arbitrarily, an elaborated approach is offered in "the
square-grid concept h/d" ) |

Figure 2 shows the central projection of the square grid, with special reference to two sets of red and blue squares.

Figure 3 presents an extract of the projection of the square grid. Note that all colored squares are of equal size.