| 摘要 |
A drafting device creating perspective views from horizontal base lines with remote horizontal vanishing points and with a remote skyline vanishing point. The drafting device includes articulated arm assemblies on opposite sides of the board. Each arm assembly includes a lower straight edge that is pivotally connected by primary and secondary arms to a pivot arm pivotally mounted at opposed sides of the drawing board, thereby establishing an adjustable four-bar linkage that allows the straight edge to be oriented at vertically varying horizontal base lines with horizontal vertical vanishing points remote from the drawing board and variable perspective angles. In combination with ordinary drafting tools and scales, the drafter can create three dimensional objects as viewed from a horizontal base line perspective.
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