Multi-Point Sky Illumination · Multi-Point Sky Illumination Cindy Brewer, Jay McGilloway, Rick...
Transcript of Multi-Point Sky Illumination · Multi-Point Sky Illumination Cindy Brewer, Jay McGilloway, Rick...
Multi-Point Sky Illumination
Cindy Brewer, Jay McGilloway, Rick Fourroux Penn State Geography
Prepared for April 2012 meeting with USGS
(K. Fishburn, E. Finelli, M. Cooley)
NE 45_45
N 0_45
W 270_45
SE 135_60
NW 315_45 (default)
5 Point NW Weighted Hillshade with Curvature
From left to right- • Curvature • Curvature and hillshade • Hillshade
120 Point Hillshade with Curvature
• 15° azimuth increments – 24 directions
• 5 altitudes - 10°, 25°, 40°, 55°, 70°
• Additional weighting on NW directions from 285°-345°
5 point 120 point
NW 5 point with curvature
5 point 5 point @ 70% transparency
Other Examples Images on left:
• Standard Arc default hillshade:
- Azimuth of 315° - Sun angle (elevation) of 45°
Black to white color ramp
Images on right: • 5 point illumination model • Raster calculated with illumination
directions of: 45°, 45°(NE) 135°, 60°(SE) 0°, 45°(N) 270°, 45°(W) 315°, 45°(NW)
• Curvature
The hillshade layers have a transparency of 10% to allow the curvature to come through. Black to white color ramps on both.
Black Point, UT
Chamblee, GA
Branford, CT
Granite City (E. St.Louis)
Hermitage, MO
Memphis, TX
Spooner, GA
Squares S Ranch, CO