sciagraphy
Concise Oxford English Dictionary © 2008 Oxford University Press:
sciagraphy /sʌɪˈagrəfi/ (also skiagraphy)
▶noun the use of shading to show perspective in architectural or technical drawing.
– derivatives
sciagram noun,
sciagraph noun,
sciagraphic adjective.
sciagram noun,
sciagraph noun,
sciagraphic adjective.
– origin C16: from Fr. sciagraphie, via L. from Gk skiagraphia, from skia ‘shadow’.
'sciagraphy' also found in these Oxford entries:

