In many DIRSIG installations (including the one at the DIRS lab), the included sample scenes are placed into read-only directories. What happens when you want to add additional materials and geometry? This post discusses a neat trick that can help. The obvious, brute-force, method copies scene contents to a writable location (via cp -R). This is clearly a poor solution for complex scenes, such as Megascene1 which takes several gigs of disc space. Furthermore, copies may end up out of sync with any patches and updates applied to the read-only version. Another approach reconstructs the scene directory in a writable location using symbolic links (UNIX ln command), making local copies only of files which need to be changed. This technique can be a pain to set up for complex scene directory layouts. Again, a local copy of the material database can become out of sync with the read-only one. Alternatively, we can take advantage of the INCLUDE_FILE directive. For a material database, we'd
A blog about the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model featuring posts contributed by the developers. This is not a user manual and it is not a training class. But, it is a place to see what the developers are doing and a little about how we do it. So think of this as a place to learn cool tips, tricks, etc.