Help with 3D

Raster 2.5D

This is the "typical" case, and most GRASS r.* modules work in this mode. The GIS layer is defined by north,south,east,west and the raster map's cell values represent the elevation.

• An introduction to raster processing in GRASS

Snippet from the Wikipedia definition: "The idea is that the program's canvas represents a normal 2D painting surface, but that the data structure that holds the pixel information is also able to store information regarding z-index (depth) as well as other information such as material settings, specularity, etc. With this data it is thus possible to simulate lighting, shadows, and so on."

Example

(spearfish dataset)

g.region rast=elevation.10m
nviz elev=elevation.10m

Raster 3D (voxels)

intro

• r3.* help pages

Example

vox50 script

Vector 3D point data

• v.in.ascii -z
• r.in.xyz

Vector 3D polygons

intro screenshot of trento

• v.in.ascii -z

Example

pyramid: the following is an example of 3D vector surfaces in GRASS standard ascii format. load with v.in.ascii.

# 3D Pyramid in GRASS:  (kernel currently unused?)
#  v.in.ascii in=pyramid.vasc out=pyramid_3d format=standard -nz
#  g.region n=150 s=-50 w=-50 e=150 res=10
#  r.mapcalc one=1
#  nviz elev=one vect=pyramid_3d
#
#  tip: in nviz try setting the raster surface transparency to 50%
#
F 5
 0 0 10
 0 100 10
 100 100 10
 100 0 10
 0 0 10
F 4
 0 0 10
 50 50 80
 100 0 10
 0 0 10
F 4
 0 100 10
 50 50 80
 0 0 10
 0 100 10
F 4
 100 100 10
 50 50 80
 0 100 10
 100 100 10
F 4
 100 0 10
 50 50 80
 100 100 10
 100 0 10
K 1 1
 40 50 40
 1 1

Visualization Tools

• NVIZ
• output to VTK
• output to POVray
• output to V5D