Displaying Range Maps

There are several ways to display Range Maps. If you want to see a flat range image, where intensity corresponds to depth, generate the range map in Heightfield format. Then the sequence of commands in Appendix C will work fine (i.e., <#1251#>hf2gil<#1251#> together with <#1252#>viewgil<#1252#>). You can also use Rayshade itself to display a Range Map, as in this example:

verbatim61#

But be aware that this is just for display purposes; pixels in this re-rendered image do not correspond exactly to those in the original image.

You can also get a more precise plot, with axes labelled, using <#1255#>GNUPlot<#1255#>. Generate the Range Map in Extended Text format, and run it through this filter to remove the background pixels and negate the depth values:

verbatim62#

Store the output from this filter in some file (e.g., <#1258#>range.plot<#1258#>). Now start GNUPlot and give it the following commands:

verbatim63#

You can change the viewpoint easily in <#1261#>GNUPlot<#1261#>: enter <#1262#>help set view<#1262#> at the command prompt for details.