DIRSIG

As many of you may have read in past posts by Niek , we have been using the Blender software heavily in the construction of scenes so they can be ingested into DIRSIG . While we have many Blender tools that work in the editing and exporting of existing scenes, they only utilize a small subset of features that exist in Blender. Blender can be viewed as the vi (or emacs) of the 3D animation world which means it can be very powerful but at times opaque to the newly initiated. After paying our dues in the apprenticeship of Blender knowledgedom, we wanted to make accessible to DIRSIG users the capabilities that have made Blender the de facto standard of the 3D animation domain. In an ongoing project that addresses the need of data sets for training machine learning algorithms and assessing the performance of target detection/exploitation algorithms, DIRS has focused on implementing tools for producing numerous instantiation of simulated scenes. Blender has been an integral part ...

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.

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...