Wednesday, November 30, 2011

VectorWorks Mapping Satellite Images on Site Model workflow

The following is a workflow to georeference satellite images (available from NearMap) and map the image onto a 3D Digital Terrain Model created by the CAD program VectorWorks. 

CAD Program [Vectorworks]: 
1. Create a new site file and nominate the Origin at a given Easting and Northing (to 100M intersection) such that site sits central to a 200M x 200M square. 
2. Draw 200M x 200M 3D polygon (Z=0) with bottom LH corner coincident with Origin. 
3. Create a 'Site Model' with a 200M x 200M Site Boarder with bottom LH corner coincident with drawing Origin. 

Geoscience Australia:
4. Determine Latitude, Longitude and Grid Convergence for the Easting and Northing in 1. above.

Vectorworks: 
5. Export 3D polygon in 2. above to .kml file with Lat, Long., and Grid Convergence as per 4. above. 

NearMap Hypertiles: 
6. Import .kml file [ensure polygon is aligned to true North]. 
7. Save tiles [use max. tile size available - file size should be <4MB].

Vectorworks: 
8. Create new texture by importing .jpg created in 7. Set size to 200,000 (200M). 
9. Apply texture to Site Model. 

The satellite image should be georeferenced precisely with the DTM. 

No comments:

Post a Comment