3D Analyst

Basic Idea

What can you do with it? Work in the 3D world so can do –Visualization of –Viewsheds, lines of sight –Steepest path descents (fall lines) –Volume and area calculations

Viewshed visible Not visible From Here

Fall line Steepest path down hill In this case over a TIN Triangular Irregular Network

Calculate Volumes and Areas And other stats

Convert 2D to 3D

The components ArcSceneArcGlobe ArcMap -- this one you know ArcCatalog – and this one also

ArcScene Allows visualization of data Allows 3D interaction with data Allows Surface Analysis ArcScene documents are.sxd

ArcGlobe

ArcGlobe Data for entire globe – but works for part of globe also Can Zoom in and view from different downward angles HUGE databases! ArcGlobe docs are.33d

3D data Rasters -- Grids of continuous (usually) surfaces –Elevation –Water Tables –Pollution plumes TINs 3D features (buildings, trees, fire hydrants) These data have Z values

Z Is an attribute Can be elevation But can also be anything else –Depth to water table –Pollutant concentrations –Etc.

Z Is an attribute Can be elevation But can also be anything else –Depth to water table –Pollutant concentrations –Etc.

Raster (Grid) data Here rainfall decreases from the NW to the SE

Raster (Grid) data Snow depth as 2D and 3D

TIN A set of non-overlapping triangles that border one another Based on point Z data So are not usually the same size So you have nodes and edges

TINs

Features

Summary 3D analyst is a powerful tool –Visualization of surfaces with Z values –Analysis of volumes and areas –Viewsheds –Steepest decent You can put 3D features (buildings, trees, fire hydrants, etc. on the surface