Selected Bibliography Architectural Graphics | Page 160

SHADE & SHADOWS ~ " j / -..\-- ' I ,.,.,· ~ .• ' I : I . Avertical edge casts a shadowon the ground plane in the sa me direction as t he bearing direction of t helight ray. The shadow and the bearing direction therefore share the same vanishingpoint. ! .., c : :rmine the shadow cast on a vertical surface by a horizontal line located above the ground plane. first project the linedown to the ground plane. Determine where the bearing of the shadow m thevertical eets surface. Then extend this point up until it intersects the light ray. 154 / ARCHITECTURAL GRAPHICS '~ '·"'--- ,,~ ' ' ......._, ' ""'-""""'·'· '· ...__........... ""'~ · A horizontal edge casts on t heground plane, or on a parallel vertical surface, a shadow that is parallel to it self. Both the casting edgeand its shadow t herefore share the sam vanishing point. e