DIRSIG

In a previous post, we discussed the advantages of using OBJ files in DIRSIG. This tutorial video shows how Blender can assign DIRSIG materials to an OBJ geometry mesh.  Basic familiarity with Blender is a prerequisite. Attributing an OBJ with DIRSIG materials (video) The idea is simple: in the OBJ file, the "use material" ( usemtl ) string will specify a DIRSIG material id rather than just an arbitrary material name.  The OBJ's "material library" ( mtllib ) string is ignored by DIRSIG.

Many users want just raw radiance data from DIRSIG.  Rather than apply a built-in instrument model, they do their own post-processing of the radiance results.  The "Raw" capture method can be used to achieve this.  It writes raw DIRSIG results without applying any spatial or spectral integration. Here's a snapshot of the Raw Capture Method configuration dialog.  We'll now work through each section.   The Spectral Range controls the wavelengths for which DIRSIG will calculate and output results.   In this example, DIRSIG will compute from 0.40 microns to 2.50 microns in 0.01 micron increments.  The output image will have 211 bands of result data.  The delta must divide the range in to a whole number of bins.  For example, the range 0.4 to 0.7 microns with a 0.2 micron delta will result in an error message when DIRSIG runs. The Spatial Response controls how many results are computed and written out per detector array element....

For quite some time, the DIRS lab has been using Blender to build small DIRSIG scenes. Blender is an advanced, open source, cross-platform, 3-D modeling package. It is available free of charge, but it has a fairly steep learning curve. We've created Blender plug-ins allowing us import and export some of DIRSIG's native formats, including GDB and ODB. Blender also allows us to use geometry with the OBJ format . We can now create new scenes from scratch by assembling geometry, placing instances using Blender, and then saving out a DIRSIG ODB file. Traditionally, we have distributed the Bulldozer application for both attributing materials to geometry and constructing scenes. This set of plug-ins allows Blender to be used as an alternative to Bulldozer for constructing scenes. Starting with the official DIRSIG 4.4.1 release, we will be distributing these Blender scripts to the DIRSIG user community. All future DIRSIG distributions will include these scripts in the dir...