Creating a 3d Density Map in ArcScene

Creating a 3d Density Map in ArcScene

A density analysis in ArcGIS takes known values for some phenomenon and spreads them around, creating a continuous density surface. This technique is often the basis for a “heat map” visualization (not to be confused with a hot spot analysis).

The function of a standard heat map can be extended by treating the new surface as an elevation surface and extruding the density values in 3d. The resulting maps show off data spikes and dips as a terrain-like representation of values.

Create a Z enabled point layer

In order to create a density surface that can later be viewed in 3d we need to add a Z attribute to our imported table data. If starting with an existing point layer you will need to export the attribute table (with XY coordinates) and re import with Z values.

 In ArcScene, open a new connection in the catalog side bar

to your data table.

 Right click on the table and choose Create Feature Class

From XY Table.

 Project your new point layer to match the project

coordinate system.

Create Density Surface

The Density Surface is your analysis surface and will be used for the color representation of you data values.

 Open the Kernel Density tool

 Add your Population field from the table of attributes

 Set a cell size

 Under Environments use the Raster Analysis Mask setting to clip the surface shape

 Open the new layer Properties and select the Symbology tab

 Choose an appropriate Stretched color pallet

 Set the Stretch type to Histogram Equalize to improve visibility

 Check the Display Background Value box and set it to show 0 as no color to remove the 0 value base of the raster.

Create Elevation Surface

Because most data ranges are underwhelming when displayed in 3d using their normal Z values, we need to create an alternate factored elevation surface to create the steep peaks and valleys we want for this visualization. You may need to experiment with various Z factors to get the right look.

 Open the Raster Calculator tool

 Add the density surface from above and multiply by the required factor

 You can un check the new layer visibility in the table of contents

 Open the original Density layer properties and choose the Base Heights tab

 Set Elevation from surfaces to Floating on a custom surface and choose the new elevation layer as the surface to extrude the Density surface by the re calculated Z values in the Elevation surface

 You can improve the appearance of clustered data spikes by turning on the Hillshade effect under the layers Symbology tab.

Created