tag:blogger.com,1999:blog-171668492012-02-14T08:27:36.040-05:00A 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.Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.comBlogger461100tag:blogger.com,1999:blog-17166849.post-80445082315108630062012-02-14T08:27:00.001-05:002012-02-14T08:27:36.068-05:00

Terragen is a terrain modeling software package that has both a free version and a commercial version available for download. This program has a nice procedural engine for synthesizing realistic terrain relief in a matter of a few minutes. Within Terragen 2 Deep Edition, we created a simple fractal based terrain with a spatial extent of 10km x 10km and exported it to OBJ format via the "micro

Michael Gartleyhttp://www.blogger.com/profile/04595605923506268602noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-13848644147803434262012-01-20T08:00:00.000-05:002012-01-20T08:00:02.611-05:00

The new DIRSIG 4.4.2 release includes 10 new demos, bringing the total number of these feature focused simulations to 53. Some of these demos have been briefly discussed in other posts (for example, the expanded Geometry Primitives and Bayer Pattern Focal Plane demos). The following is a list of the new demos in the 4.4.2 release: Bayer pattern focal plane A set of example BRDF materials LIDAR

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-13621265558605212652012-01-16T12:24:00.000-05:002012-01-18T13:24:02.468-05:00

The Final Release of DIRSIG 4.4.1 is out. This release is primarily a maintenance release to address a few bugs in the 4.4.0 release. The following is a summary of fixes and features added in this release: First release to include a Windows 64-bit version Improvements to correlated deviate models used for jitter The frequency spectrum can now (optionally) include the phase New

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-21602767118672379982011-12-08T23:00:00.006-05:002012-01-18T13:25:16.791-05:00

One of the more interesting areas of development right now for laser radar are "waveform" LIDAR systems. Unlike Linear-mode (Lm) or Geiger-mode (Gm) system that collect a relatively small number of height measurements per GSD, a "waveform" LIDAR (wLIDAR) essentially digitizes the returned flux during the time window at some time resolution. That means you have intensity information at all the

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-81938366088193358962011-10-21T10:09:00.008-04:002012-01-18T13:25:04.302-05:00

Like most ray tracing environments, DIRSIG offers a number of convenient primitive objects to use in place of facetized geometry. Aside from offering a quick way to construct a (simple) scene, primitives have mathematically defined surfaces so there is no reason to worry about edges between facets. In contrast to vertex normal interpolation which helps smooth the appearance of facetized objects,

Adam Goodenoughhttp://www.blogger.com/profile/11244805715280113936noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-56846474875988265092011-10-04T14:00:00.004-04:002012-01-18T13:23:12.597-05:00

One of the new features that will be in the upcoming DIRSIG 4.4.2 release is something that we have been calling "data-driven focal planes". This mechanism had been on the drawing board for many years and we finally had a reason to implement it on our contract to help model the Landsat Data Continuity Mission (LDCM) sensors, or what many of you will come to know as Landsat 8 when it is launched

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-12369193862877655692011-10-04T12:01:00.004-04:002012-01-18T13:22:52.435-05:00

The next DIRSIG Basic Training course will be held at the Marriott Residence Inn at Fair Lakes in Fairfax, VA on November 1st - 3rd, 2011. More information is available on the DIRSIG training webpage

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-82187886871885568112011-09-30T11:39:00.008-04:002011-09-30T12:32:45.354-04:00

One of the fundamental modules in D5 supplies a model of the earth (or other, roughly ellipsoid planet) to the core representation of the DIRSIG universe. The distributed version of D5 will likely contain a simple, material-mapped sphere representation of the earth by default (to keep download sizes reasonable), with the option to obtain more detailed (and more correct) models.To this end we've

Adam Goodenoughhttp://www.blogger.com/profile/11244805715280113936noreply@blogger.com1tag:blogger.com,1999:blog-17166849.post-78448244126729995032011-09-16T13:37:00.003-04:002011-09-16T14:06:02.562-04:00

The transition from DIRSIG 3 to DIRSIG 4 was a major shift towards a more modern code architecture and a more flexible simulation design. The goal was to address the development challenges faced at that time and to be ready for the new features and capabilities that would come.During the past few years, we have added new modalities (particularly LiDAR), new platform support (Windows), an entirely

Adam Goodenoughhttp://www.blogger.com/profile/11244805715280113936noreply@blogger.com3tag:blogger.com,1999:blog-17166849.post-82435817137588861352011-06-15T11:55:00.005-04:002012-01-18T13:28:38.039-05:00

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

Rolando Raqueñohttp://www.blogger.com/profile/14064894502654930100noreply@blogger.com2tag:blogger.com,1999:blog-17166849.post-87071226188487422982011-05-25T18:05:00.000-04:002011-05-25T18:05:21.579-04:00

A new "refinery" scene will be included in the next DIRSIG release. The scene was inspired by the Ras Lanuf oil refinery in Libya.  It features an industrial site sitting on a desert-water interface.  Two DIRSIG renderings are shown below. The highlight is the refinery itself, featuring pipes and general industrial clutter.  The plant connects to a railroad track and an access road.  A small

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-36751552915007857222011-05-02T10:11:00.001-04:002012-01-18T13:22:42.560-05:00

The next DIRSIG Basic Training course will be held at the RIT Campus on May 25-27, 2011. The course is open to everyone. More information is available on the DIRSIG training webpage

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-13545712722181291052011-03-29T08:00:00.004-04:002011-03-30T11:37:00.484-04:00

The RIT Digital Imaging and Remote Sensing (DIRS) Lab has a booth (#3014) in the Exhibition Hall at this year's SPIE Defense, Security, and Sensing symposium in Orlando, FL (April 25-27). Adam Goodenough, Niek Sanders and myself will be hanging out at our booth talking to conference goers about DIRSIG. Other lab personel will be on hand to discuss RIT's other research interests ranging from MSI

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-47920659325447257812011-03-11T08:00:00.000-05:002012-01-18T13:23:49.888-05:00

The Final Release of DIRSIG 4.4.1 is out. This release is primarily a maintenance release to address a few bugs in the 4.4.0 release. The following is a summary of fixes and features added in this release: First release to include a Windows 64-bit version Improvements to correlated deviate models used for jitter The frequency spectrum can now (optionally) include the phase New

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-17920565082143739972011-02-28T11:04:00.001-05:002011-02-28T11:10:22.744-05:00

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

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-42002878958093962162011-02-24T19:13:00.000-05:002011-02-24T19:13:05.647-05:00

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

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-88038150157145574152011-02-01T05:00:00.001-05:002011-02-01T05:00:04.083-05:00

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

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-36948968284332665062011-01-27T08:00:00.003-05:002011-01-31T17:10:22.141-05:00

Last week, Brian Flusche (one of our students) defended his Ph.D. dissertation entitled "Analysis of Multi-Modal Fusion for Target Detection in an Urban Environment". Brian's research reflects how many people are using DIRSIG to simulate data in an effort to explore the value of new and novel exploitation schemes. In this case, Brian was trading the value of hyper-spectral imaging vs.

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-59498865219391749922011-01-25T05:00:00.000-05:002011-01-25T05:00:01.427-05:00

We've just put together another DIRSIG "demo" simulation.It shows a camera placed indoors. The scene is illuminated by both a secondary source at the ceiling and through a window cut-out at the far end of the room.This demonstration will be included in the next DIRSIG release.

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-90736031212743186382011-01-14T16:38:00.001-05:002012-01-18T13:23:40.309-05:00

The next DIRSIG Basic Training course will be held at the NASA Ames Research Center on Feb 23-25, 2011. The course is open to everyone (not just NASA employees). More information is available on the DIRSIG training webpage

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-18788327460388821202011-01-05T08:00:00.000-05:002012-01-18T13:29:03.705-05:00

We have placed an update to the MegaScene1 distribution on myDIRSIG. The major aspect of this release is that it comes with a set of DIRSIG4 .scene files. This release also includes updates to material properties including the conversion of the tree leaf optical properties from extinction to transmission. We have found that changing this optical property provided speed ups because a large

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-14127590357245747062011-01-01T10:29:00.002-05:002012-01-18T13:25:43.290-05:00

This release is primarily a maintenance release to address a few bugs in the 4.4.0 release. A "release candidate" is a preview of the next release of DIRSIG. This version of the software is produced when we feel the software is ready for release, but we would like some last-minute user feedback. Our early adopters always help spot a few lingering issues that our release quality control process

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-80273859718198920202010-11-04T08:00:00.005-04:002011-02-01T11:52:15.042-05:00

A common question we get asked is how to visualize the point cloud data produced by either the Linear-mode or Geiger-mode LIDAR simulations. First, you should remember that the point cloud files produced by the "APD Processor" are simple ASCII/text files. Each line is the entry for a single return or "point" in the point cloud, including the point location and some attributes that vary

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com2tag:blogger.com,1999:blog-17166849.post-76280498326859771252010-10-28T13:18:00.009-04:002010-10-28T15:37:07.307-04:00

We often want the ability to add clouds to a large scale scene in order to see the reflective, transmissive and shadowing effects on the scene. In these cases we are not so much concerned with the absolute radiometry of the clouds (true multiple scattering, exact modeling of limb regions, etc..), as we are with capturing bulk effects (single-scattering contributions, transmission effects,

Adam Goodenoughhttp://www.blogger.com/profile/11244805715280113936noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-56317930920210594882010-10-17T20:00:00.001-04:002012-01-18T13:24:29.084-05:00

Three weeks ago we announced a "release candidate" for DIRSIG 4.4.0. In the time since, we had quite a few early adopters try out 4.4.0 and provide us with feedback. Those improvements and bug fixes have now been incorporated into the official release of DIRSIG 4.4.0, which is now ready for download on myDIRSIG for registered users. Like we said at the time of the release candidate, we are

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-70733011898939667932010-10-14T20:00:00.001-04:002010-10-15T14:09:56.908-04:00

Over the past few years we have been doing more simulations of video systems. Perhaps you have seen the video simulation of MegaScene1 with the cars driving down the streets as would be acquired from a circling UAV: So how do we make these videos? It is really a simple tool chain involving a tool that is distributed with DIRSIG and another tool that can be downloaded from the web. For this

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-21929621894432842722010-10-08T08:00:00.004-04:002010-10-08T08:31:28.072-04:00

When we first started on the DIRSIG model in the late 1980s, 3D computer graphics was still in its infancy. At the time, standard file formats for 3D geometry were still being established. In addition, the DIRSIG model had the need for a specific set of per-facet attributes (material ID, thickness, override temperature, etc.) that are still somewhat unique in the 3D modeling community. As a

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-5160649057849266602010-10-07T08:00:00.003-04:002010-10-07T08:00:09.559-04:00

In the DIRSIG 4.4.0 release users will find that we made some modest improvements to the classic Urban and Forest scenes. Primarily, we improved the scene geometry by replacing the decade old, low facet count trees with the high fidelity trees we have been using in other scenes. We have also cleaned out a bunch of unused files and tried to improve the organization of the respective scene

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com1tag:blogger.com,1999:blog-17166849.post-33259458393531405052010-10-04T08:00:00.000-04:002010-10-04T08:59:34.085-04:00

One of the ways we try to teach users about specific features is by making a "bare bones" simulation as a demonstration of that feature. These "demos" don't usually generate a very exciting output data product, but they are fully self-contained (no external data required) simulations that focus on how to configure a specific feature. We have been distributing our growing set of demos with DIRSIG

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-59037502273781151772010-10-03T12:00:00.000-04:002010-10-03T18:30:35.725-04:00

Here is a look at the input files that go in to a DIRSIG simulation.Each icon in the dirsig_edit tool corresponds to an XML file:Behind the scenes, these files are given the following extensions:.scene.atm.platform.ppd.tasks.optionsThe options file is, by happenstance, optional.So what goes in to the ".sim" manifest file? It's simply a list of the files assigned to each component. A typical sim

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-44455024051638569852010-09-29T08:00:00.003-04:002010-09-29T08:00:12.986-04:00

We are often asked what programs can view DIRSIG's image outputs and how to import the raw DIRSIG image data files into other tools for further processing.For basic image viewing, DIRSIG-4.4.0 now includes a very simple viewing tool. Launch it from the main simulation editor window by selecting the "Start image viewer" option from the "Tools" menu.If you run your simulation from the GUI

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-82435060215615047372010-09-24T16:51:00.015-04:002010-10-08T08:39:47.989-04:00

Included in the DIRSIG-4.4.0 release candidate is a new "warehouse" scene.As shown below, this scene features a fairly high amount of geometric clutter. The scene includes stacks of wood palettes and crates, steel I-beams, piles of corrugated steel panels, steel pipes, shipping containers, concrete barriers and other "cultural clutter" objects that might be found at a site like this. The scene

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-58654879861559685932010-09-24T12:22:00.011-04:002010-10-15T16:57:57.219-04:00

We are pleased to announce a "release candidate" for DIRSIG 4.4.0 has been posted to myDIRSIG. A "release candidate" is a preview of the next release of DIRSIG. This version of the software is produced when we feel the software is well tested and ready for release, but we would like some last-minute user feedback. We are very excited about this release as it packs in a bunch of new features and

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-59486152490375990532010-09-24T12:00:00.004-04:002010-09-24T12:56:39.632-04:00

Niek started this blog 4 years ago, but then let it go dormant. We recently decided it would be a good thing to have some sort of way to publicly show each other and the user community some of the fun, cool and helpful things we are working on from time to time.So please stay tuned in the future for news, tips, tricks, etc. about the DIRSIG model.

Scott Brownhttp://www.blogger.com/profile/09598005664838220635noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1155840530267554622006-08-17T14:45:00.000-04:002006-08-17T14:48:50.280-04:00

The next release of DIRSIG will feature two major internal optimizations. One which will significantly speed thermal runs. The other which will speed unpolarized radiometric calculations--especially noticeable in hyperspectral cases.New functionality includes a user-configurable interactive mode, which allows for a user-specified ray/solid angle to be traced and for arbitrary data to be

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1155754822671902432006-08-16T14:59:00.000-04:002006-08-16T15:00:22.686-04:00

The Urban (Hawkeye) scene will soon be made available with secondary sources enabled. For now, these secondary sources can only be rendered using DIRSIG3. Support for this feature is planned for DIRSIG4, but there is no fixed implementation date.

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1152670282146157632006-07-11T22:02:00.000-04:002006-07-11T22:11:22.156-04:00

The DIRSIG-4.0.7 build is now available off the myDirsig website. Besides a bunch of smaller bug fixes, the key improvements are to the LIDAR and Polarization models. This is also the first release in which Voxelized Grids can be reliably used (demonstration).This release also marks the first time that the DIRS Laboratory has put out an x86-64 based Linux build. Assembled on Fedora Core 5, it

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1139001421392714872006-02-03T16:11:00.000-05:002006-02-03T16:17:01.410-05:00

The DIRSIG4 codebase now contains a make_dem tool, outputting either ascii or ENVI image digital elevation maps. Gnuplot can visualize the ascii output (via the splot command). ENVI or Freelook can be used to render the image output.The tool currently requires a .cfg file as input, an annoying limitation. This is due to a design issue in the geometry subsystem; it will be addressed in the

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1134762108100880162005-12-16T14:37:00.000-05:002006-06-29T13:07:19.560-04:00

According to the webpage, DIRSIG4 is currently only supporting Solaris/SPARC 2.9+ and Linux/x86 2.4 kernels. The next set of releases (dirsig-3.6.5 and dirsig-4.0.7) will come with experimental support for the x86-64 platform. Internally, we have a cluster of Athlon64 machines running Fedora Core 5. The added registers on the 64-bit x86 architecture give a significant speed boost over the 32-

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1134705061370266772005-12-15T22:49:00.000-05:002005-12-15T22:52:54.223-05:00

It occurred to me that the ODB instancing can be used on both solid geometry and voxelized grids. Among other things, this means that grids no longer need to be axis-aligned. Simply stick the solid geometry or grid in a separate ODB file and instance it using the technique discussed in Instancing ODBs.

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1134579416828746712005-12-14T11:45:00.000-05:002005-12-14T11:57:24.706-05:00

Another feature coming in DIRSIG 4.0.6 is support for regular voxelized grids. The advantage of these structures is that they allow for extremely fast intersections of regularly spaced boxes. The backend code for implementing these grids is also used by DIRSIG to implement support for the QUIC concentration map outputs.In the ODB file:REGULAR_GRID { INSERT_POINT = 0,0,0 DELTA_X = 20

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1133885057026362612005-12-06T10:56:00.000-05:002005-12-06T15:02:15.636-05:00

The DIRSIG team is working with Los Alamos National Laboratory (LANL) to integrate the Qwick Urban industrial Complex (QUIC) plume model in to DIRSIG.Starting with version 4.0.6, the functionality to read in a QUIC gas concentration output will be available. The functionality is currently experimental, and the syntax is liable to change in future DIRSIG revisions. An example of an NH3 plume:PLUME

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1129505130981756212005-10-16T19:18:00.000-04:002005-10-16T19:27:45.843-04:00

A helpful hint if you are using PGM images with DIRSIG maps. It is orders of magnitude faster to load a binary (aka "raw") PGM than an ASCII one. The difference is especially visible when loading large images, such as 4k by 4k textures in Microscene1.You can check the PGM format by opening the .pgm file in a text editor. If the first characters in the file are "P2", then you have an ASCII image (

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1128879080738929462005-10-09T13:26:00.000-04:002005-10-09T13:31:34.826-04:00

The current development version of DIRSIG4 supports ODB instancing. Like object instancing, the same ODB can be used multiple times via an affine transformation. This also gives a quick way to rotate entire ODB files.Here's the new syntax:OBJECT { ODB_FILENAME = ./foxbat.odb UNITS = METERS INSTANCES { INFO = 0.00, 0.00, 0.0, 1.00, 1.00, 1.00, 0.00, 0.00, 0.0 INFO = 0.00, 0.00,

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1127842608547554032005-09-27T13:32:00.000-04:002005-09-27T14:16:45.110-04:00

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

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0tag:blogger.com,1999:blog-17166849.post-1127792643904350522005-09-26T23:40:00.000-04:002005-09-26T23:45:04.250-04:00

I'm one of the three core developers on the DIRSIG project. This blog is simply an experiment in information dissemination. It's intended for both power users and developers. Hopefully, it will make our development process a bit more transparent.

Niek Sandershttp://www.blogger.com/profile/12140436634766242751noreply@blogger.com0