Release Notes

DIRSIG5 2023

DIRSIG5 2023.52

Under the hood
- The scene data model (HDF) lat/lon/alt was increased from single to double precision. This improves pointing precision for high altitude (exo-atm) sensors.
- A series of optimizations have increased the run-time performance of simulations using multiple scenes.
- An optimization was added to improve performance for simulations employing large numbers of user-defined sources.
- The internal ephemeris plugin API now describes exo-atm sources (Sun and Moon) as ECEF locations with velocities rather than in terms of a scene relative vector.
  - This improves multi-scene simulations and allows for location dependent solar/lunar geometries.
- DIRSIG5 can now be run "scene less", meaning a simulation using just the EarthGrid plugin is valid.
  - See the new StkImport1 demo for an example.
- The BasicPlatform sensor plugin now shoots ECEF rays when a non scene ENU coordinate system is used for motion. This improves pointing precision for high (exo-atm) sensors and introduces flexibility for scene-less simulations.
Features
- Space situational/domain awareness (SSA/SDA) type simulations are now supported in DIRSIG5.
  - There are specific requirements for setting up these types of simulations. See this section of the Space Situational Awareness Handbook for more guidance.
  - See the updated Ssa1 and the new EarthShine1 and MoonSat2 demos for working examples.
- Environment variable support was added for external program paths
  - In an effort to improve portability of simulations, the MuSES plugin and MODTRAN backends now support using environment variables to avoid hard-coded paths to executables, data directories, etc.
  - An environment variable is indicated as a string wrapped by ${ and } (e.g., ${MUSES_EXE}, ${MODTRAN_EXE}, etc.). If an incorrectly formatted variable is found, or the indicated variable does not exist, an error will occur.
- Improved support for MODTRAN6
  - The DIRSIG4-era make_adb atmospheric database builder will now work with MODTRAN6 without the need for the script wrapper required in previous releases.
  - The DIRSIG5-era Modtran Tape backend used by the NewAtmosphere and FourCurveAtmosphere atmospheric database builders will also now work with MODTRAN6 without the need for the script wrapper required in previous releases.
  - The new MODTRAN6 JSON backend used by the NewAtmosphere and FourCurveAtmosphere atmospheric database builders was introduced, which utilizes the modern JSON input interface to MODTRAN6.
- The Modtran Tape backend that is used with atm_builder and fourcurve_builder now includes a new "parameterized" configuration option:
  - This allows the user to define a basic MODTRAN configuration without needing to pre-build a tape5 file. Note that this feature can be used with MODTRAN6 as well.
- An option to "remove the sensor path" was added to the NewAtmosphere and FourCurveAtm atmospheric radiative transfer plugins.
  - This is a run-time option to set the radiance and transmission to 0.0 and 1.0 respectively for the first path segment between the sensor and a scene object. This effectively changes what is usually a sensor reaching radiance to a scene leaving radiance.
- Improvements to the scene_tool utility to make it easier to lookup various truth indexes.
- The DeltaReflectance and DeltaTransmittance surface optical properties were introduced.
- The Tabulated and Commanded mount models in BasicPlatform now support platform-relative translation.
  - See the new CommandedMount2 and TabulatedMount2 demos.
- The DIRSIG5 command-line schedule modification options now include an --end_capture option.
  - This option can be used alone or combined with the --start_capture to simulate a subset of captures in a multi-capture simulation.
- Graphical User Interface (GUI) improvements when working with JSIM-based simulations.
  - Added JSIM editors for the THERM and NSRDB weather plugins.
  - Added the ability to setup and modify the recently added parameterized setup in the MODTRAN Tape backend for the NewAtmosphere plugin.
Deprecations and Functional Changes
- The DIRSIG5 command-line instance report option is no longer supported.
  - This old and tedious method for relating geometry truth indexes back to input scene geometry has been replaced by the new lookup tool in the scene_tool utility.
- The ClassicExtinction optical property was changed from being internally modeled with a "delta" function (light emerges from the back side going in the same direction) to a "diffuse" function (light emerges from the back side going in a random direction in the hemisphere).
  - This optical property was primarily used in DIRSIG4 and many older scenes to model vegetation transmission (leaves) and the updated diffuse treatment more accurately captures how light interacts with vegetation.
  - However, this optical property was also used in some cases to model materials such as "glass". With this change, the glass will now be appear "frosted" as light paths will emerge from the backside going in random directions rather than straight through. To model a material like glass consider using the DeltaTransmittance property instead. See the updated versions of the BundledObject1 and Parking1 demos for working examples.
Documentation
- The updated truth manual reflects the options available in DIRSIG5.
  - For DIRSIG4 users, the old truth manual is still available.
- The new VDB plugins manual explains how to use both the CloudVDB and PlumeVDB plugins.
- Added a new section to the BasicPlatform sensor plugin manual describing the output units.
- Added internal links to the individual properties in the summary table in the Surface Optical Properties manual.
- Added some simple figures to better explain the differences in the directional distributions of the various properties in the Surface Optical Properties manual.
- Updates the scene2hdf scene compiler manual, including the new --skip_unused_materials option.
- More additions to the Troubleshooting Guide, including more coverage of MODTRAN generated errors.
- The Space Situtational Awareness Handbook received some minor updates, including a section describing the differences in these simulations between DIRSIG4 and DIRSIG5.
- Added illustrations to all the motion model manuals to clarify the reference frame for motion rotations.
Demonstrations
- Updated
  - Ssa1
- New
Bugs
- Fixes to scene2hdf to correctly handle multiple TDF files in a single scene.
- Improvements to the BasicPlatform sensor plugin:
  - Fixed the built-in detector model when the minimum number of electrons is not zero.
  - Fixed the aperture not changing the output units when not using the detection model.
  - Fixed the STK report file readers to now allow the "number of points" variables to be a decimal value (some versions of STK write the files this way).
- Improvements to the graphical user interface for JSIM files:
  - Fixes to the BasicAtmosphere JSIM editor.
  - Fixes to the BasicPlatform JSIM editor.
  - Improved the layouts of many of the JSIM editor windows to work better on smaller screens.
- Fixes to the Earth model plugins.
- Fixes to thermal water plugin.
- Fixes to path tracing deviant weighting with sources.

DIRSIG5 2023.12

Features
- Introduction of the new vdb_tool command-line program, which provides ways to create, modify and interact with OpenVDB files containing voxelized (volumetric) geometry.
  - This includes a replacement for the stand-alone blackadar plume model introduced in the previous release.
  - It also includes tools to convert DIRSIG4-era RegularGrid files and arbitrarily sampled ASCII/Text XYZ files.
- Introduction of the new ems_tool command-line program, which provides ways to generate, manipulate and interact with DIRSIG emissivity files.
  - This includes the ability to generate large curve databases to use with texture maps from smaller databases or from ENVI statistics files.
- Introduction of native AutoDesk FBX support.
  - An FBX file can now be used as a source of facetized geometry in a GLIST file. See the updated Parking1 demo for an example.
  - The new FBX export tool was added to the scene_tool utility, which will produce a FBX file for the scene. This FBX currently does not contain materials, but it does capture the geometry hierarchy, including dynamic instance motion that can be previewed in 3D tools including Blender, Maya, etc.
- Improved support for abundance truth in multi-scene simulations.
  - Material abundances are now correctly gathered across multiple scenes. Additionally, the user can use the new scene names feature to indicate that they only wish to collect abundance for a specific scene in a multi-scene simulation.
  - Tagged abundances are now correctly gathered across multiple scenes.
- Improvements to the scape_tool utility:
  - An option was added to specify the material ID for all the facets in the resulting terrain.
  - An option was added to automatically add a simple 2D UV coordinate system to all the facets in the resulting terrain.
  - The output OBJ file now utilizes shared vertices, which results in significantly smaller OBJ files.
- Introduction of support for "default bands" in the ENVI image files produced by DIRSIG.
  - This allows the user to optionally define what bands (either 1 or 3 bands can be specified) will be automatically displayed upon an initial load of the image in ENVI and other electronic light table (ELT) applications.
  - The DIRSIG image_tool convert mode will automatically use these default bands if the --bands option is not supplied.
- Changes to the default spectral coverage windows.
  - The upper wavelength in the predefined "SWIR" windows in scene2hdf was extended from 2.52 microns to 2.55 microns.
  - The default FourCurveAtmosphere database was update to have a broader spectral range, now supporting 0.35 → 2.55 microns (previously 0.38 → 2.52 microns).
Migration of the command-line interface (CLI) parsing for several of the tool-based utilities to a new backend that improves modularity and ease of use.
- These changes are reflected in the respective tool manuals (see ems_tool, facet_tool, scene_tool, sli_tool and vdb_tool).
Improvements to the Graphical User Interface (GUI)
- The Output tab of the Simple Capture Editor now lets you specify the "default bands" to be automatically displayed in ENVI and other ELT applications.
- The DIRSIG image viewer will now pre-select (but not automatically display) the "default bands" in the ENVI image file (if supplied).
- The initial state of the Clock tab in the Focal Plane Editor was updated to allow the user to immediately set the integration time and rolling shutter variables.
Documentation
- The new FBX base geometry option was documented in the GLIST manual.
- The new name option for a scene was added to the JSIM manual.
- The truth manual was updated to document improvements to the material abundance and tagged abundance collector in multi-scene simulations.
- Improvements to the scape_tool manual document recently added features.
- A manual for the new vdb_tool was introduced.
- A manual for the new ems_tool was introduced.
- A manual for the water medium plugin and supporting wave spectrum interface and IOP models were introduced.
Demonstrations
- Introduction of the new Brdf3 demo, which focuses on the impacts of surface roughness in a common BRDF model.
- Introduction of the new SubPixelObject2 demo, which focuses on hypersampling full-fill targets that have small (sub-pixel) features. In this case, a hot spot on the hood of a car.
- Updates to the Muses1 demo to note differences between DIRSIG4 and DIRSIG5 import mechanism.
- Updates to the PlumeVDB1 demo to include the original LWIR simulation looking at an emissive SF₆ plume and new a SWIR simulation looking at an absorptive methane (CH₄) plume. The README was updated to note the replacement of the old stand-alone blackadar utility with the new vdb_tool.
- Updates to the Parking1 demo to include an alternate version where all the OBJ files have been converted to FBX.

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DIRSIG5 2022

DIRSIG5 2022.48

Deployment
- The MacOS application bundle is now code signed and notarized (which which confirms for the user that the application was created by RIT and has not been modified by a 3rd party).
  - This enables the Apple Silicon (ARM64) release for M1 and M2 machines to run without needing to disable System Integrity Protection (SIP).
  - See the updated notes in the installation manual for more details.
- The Windows installer is now code signed, which confirms for the user that the application was created by RIT.
  - However, Windows Defender might still flag the installer as an "unrecognized app" and require additional user authorization to install. See the updated notes in the installation manual for more details.
Features
- The graphical JSIM editor has been improved to allow the user to run simulations as well as edit them.
  - The layout of this tool was changed to use modal, popup editor windows.
  - A DIRISG4-era .sim file can be migrated to a DIRSIG5-era JSIM file.
  - The order of plugins can now be modified so that plugin overrides can be managed.
  - The unknown (user-defined) plugin editor now provides basic JSON formatting checks.
  - Minimal support for the medium_list is included.
  - The editor has a basic "unsaved changes" check before running.
- Introduction of the MuSES plugin, which provides an improved, Level-1 integration between DIRSIG and the MuSES signature prediction model.
  - This plugin ensures that the location, orientation, date, time, materials and weather are automatically synchronized between the two models.
- Introduction of the PlumeVDB plugin, which provides a way to import external plumes (factory stacks, cooling towers, etc.) into DIRSIG using the OpenVDB voxel description.
  - This also includes a port of the DIRSIG3 and DIRSIG4 era puff-based plume model derived from Alfred Blackadar. The blackadar plume utility allows the user to generate single species plumes that can be assigned absorption and/or scattering properties via the PlumeVDB plugin.
- Introduction of the scene_tool utility to extract information from compiled scenes (aka scene HDF files).
- Introduction of the facet_tool utility to convert and manage facetized geometry files.
- Introduction of the direct Curve Map, which allows the user to treat an image as an index map into a curve database.
- Improvements to the atm_builder utility.
  - The tool now supports a user-supplied list of altitudes to use rather than ones derived from the various scene altitudes and sampling (see the --altitude_list option).
  - The tool now support command-line options to override the default sky sampling range and interval (see the --sky_zenith_sampling and the --sky_azimuth_sampling options).
- Improvements to the atmospheric database builders (make_adb, atm_builder, etc.) to now run a suite of MODTRAN verification tests upon startup to help the user diagnose configuration issues.
- Improvements to the image_tool conversion mode
  - The --autoscale=none is now always a manual scaling defined by the optional --gains and --biases arguments (the respective defaults for those are now 1 and 0, respectively). Before some syntaxes would still result in a min/max scaling.
  - The new --output_filename option was added to let the user specify the name of the output file.
- Improvements to the ChipMaker plugin
  - Channel descriptions can now include gain and bias ranges, which will be used to scale the normal radiance or reflectance outputs to different units or to N-bit output (see here for more details).
  - Channel descriptions can now include a simple additive noise range. This noise is applied after the optional internal scaling operation (see here for more details).
  - The user can now define one or more processing steps as part of the configuration. These steps can be used to trigger any common command-line task (post-processing, format conversion, etc.) on the image data produced for each chip (see here for more details).
- Improvements to the Graphical User Interface (GUI)
  - The instrument editor now provides access to the optional aperture parameters and lens distortion configurations.
  - The focal plane editor now lets the user enable time-delayed integration and to enable hypersampling.
  - Improvements were made to address style sheet overrides when using Dark Mode.
- Improvements to the (experimental) inline processing feature in the BasicPlatform plugin
  - The original input filename syntax has been replaced by a string variable that is automatically replaced with the current filename.
  - A more complex example of generating a video file as part of the simulation is now described in the plugin manual and an example included in the TrackingMount1 demo.
- Improvements to the OrthoImage plugin to optionally include truth data in the output data cube.
- Addition of the instance report option to the DIRSIG5 run-time, which will produce a JSON report that can be used to link various truth indexes back to base geometry and instance information.
- Addition of absolute time support and time interpolation to the .til (map time sequences) files.
  - See the TemperatureMap1 demo for a working example.
- ENVI spectral library (.sli) support was added to the SimpleReflectance and SimpleTransmittance optical properties and the new Curve Map.
  - The sli_tool utility was introduced to help the user create and manage these SLI files.
- Jitter is now supported in DIRSIG5 when using the FlexMotion model for in-scene object motion.
Documentation
- The new Troubleshooting Guide was introduced as a central source for resolving common problems.
- A section describing "hypersampling" was added to the BasicPlatform plugin manual.
- The MODTRAN related documentation has been reorganized and enhanced:
  - Issues specific to getting the atmospheric database builders (make_adb, atm_builder, etc.) to work with MODTRAN have been migrated from the old "MODTRAN Troubleshooting Guide" to a section in the new general Troubleshooting Guide.
  - The remaining content in the old "MODTRAN Troubleshooting Guide" is now in the document titled the MODTRAN Integration Guide.
- The base geometry section of the GLIST manual was updated to include new sections about object HDF facet geometry, material reassignment and sub-object properties and motion.
- New utility program manuals
  - A manual for the new facet_tool was added.
  - A manual for the new scene_tool was added.
  - A manual for the new sli_tool was added.
- New plugin manuals
  - The Blackadar plume utility manual
  - The PlumeVDB plugin manual
  - The MuSES plugin manual
Demonstrations
- New demonstrations:

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DIRSIG5 2022.12

Features
- Native support for Apple Silicon (ARM64) processors.
- Simplified deployment of the MPI-enabled version of DIRSIG5
  - Rather than a separate set of executables, MPI is now enabled with run-time option. See the Parallel DIRSIG5 Guide for more information.
- An important difference in how DIRSIG4 and DIRSIG5 model the spectral component of LIDAR transmitters (lasers) has been documented and addressed in the LIDAR demos.
- Improved console output controls
  - The DIRSIG5 toolchain (scene2hdf, dirsig5 and atm_builder) now supports the --log_level option, which allows the user to control the verbosity of output messages including enabling debug messages. See this section of the DIRSIG5 Command-line Guide for more information.
- The BasicPlatform plugin has a new option to easily scale the resolution of all the focal planes in a platform from the command-line.
- The PointCollectors plugin now supports a directional collection mode in addition to the hemispherical and spherical collection modes.
- A new editor for JSIM simulations has been introduced.
  - Although not fully capable yet, this editor allows users to create and edit JSIM configurations.
  - A short tutorial has been added to introduce the user to the basics of using the editor.
- Replacement of the old envitopnm utility with the new image_tool utility.
  - This more powerful tool allows the user to process images in bulk (rather than indidividually) and directly convert them to JPEG, PNG, etc.
- Entire GDB and OBJ files can now be assigned a single temperature in a GLIST file via the <temperature> element.
- Introduction of the bundle inventory, which is a collection of pre-built, bundled object scene assets that can be easily added to scenes.
Documentation
- The old "DIRSIG4 Manual" has been retitled the DIRSIG4 Command-Line Guide.
- The old "DIRSIG5 Migration Manual" has been retitled the DIRSIG5 Command-Line Guide and reworked:
  - A more complete description of the command-line options has been captured.
  - The new set of options to generate JSON log outputs has been introduced.
  - Any of the old "what’s new about DIRSIG5" material has been migrated to the DIRSIG Model Introduction document.
  - Any of the old install/configuration material was migrated to the Installation Guide document.
  - The MPI specific material (which is now just a command-line switch) is still located in the Parallel DIRSIG5 Guide.
- The DIRSIG4-era atmosphere documentation was improved.
  - A new manual for the BasicAtmosphere plugin was introduced, which describes the "SimpleAtm", "UniformAtm" and "ClassicAtm" DIRSIG4 modes supported by this plugin
  - A new manual for the make_adb tool was introduced that attempts to capture how the tool interacts with MODTRAN (including a table of MODTRAN variables modified by the tool), the various configuration options (the "old" MODTRAN installation configuration file vs. profiles in the user settings), options in the .atm file (including an example of an internally stored "tape5" file) and command-line options.
  - A new manual for the ADB file format was introduced.
- The major overhaul of the material documents has been completed:
  - A new material database manual has been introduced.
    
    The material manual includes a few examples and discusses special cases (empty/proxy materials, material/mixture map materials, source materials and the DIRSIG3-era format).
  - Updates to the surface properties manual were introduced.
  - A new bulk properties manual was introduced.
  - The radiometry solver and temperature solver manuals are heavily cross-linked now.
- A manual for the new image_tool utility was introduced.
- Unit conversions were corrected and improved in the THERM temperature solver documentation.
- The GLIST manual was updated to document the minscale and maxscale options to the random fill instancing options.
- The scene2hdf manual was updated to document the DIRSIG_CACHE_DIR override.
- The BasicPlatform plugin manual was updated to include a section of related documents for platform motion, mounts, truth, etc.
- The FAQ was updated with a few clarifying questions and anchors for easy linking.
Demonstrations
- The thermal demos have been updated to be reflect increased DIRSIG5 compatibility.
- The LIDAR demos have been updated to be address poorly configured spectral sampling configurations (see this section of the Lidar Modality Handbook for more information).
- The temporally varying temperature map capability is now supported in DIRSIG5.
- Added README files to demos that did not contain one:
- New demonstrations:
  - PointCollectors1
Bugs
- Fixed a bug where large scene map images could not be loaded.
- Fixed a bug where RGB images would incorrectly trigger a recently added "high bit depth" error check.
- Fixed a bug where a BasicPlatform plugin configuration with TDI would trigger a range error in the platform motion.
- Fixed a bug with path radiance and transmission discontinuities for sensors viewing the horizon.
- Fixed a bug in how DIRSIG5 models RGB maps that would result in a spectral artifact at 0.500 and 0.600 microns.

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DIRSIG5 2021

DIRSIG5 2021.42

This release produced shortly after the 2021.40 release was produced to address some important bugs in the graphical user interface (GUI).

Bugs
- Fixed a bug where the user could not open or save a PPD file from a simulation in the GUI.
- Fixed a bug where the right-click menu in the "Component Browser" presented the user with invalid options for an empty component group.
- Fixed a bug where the output log from the GUI would be incomplete or empty if the simulation failed.

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DIRSIG5 2021.40

Features
- Updated Ray-Tracing Core
  - The internal ray tracing capabilities have been upgraded to the latest version of Embree (3.13).
  - All DIRSIG4-era built-in (aka "primitive") geometry types are now supported in DIRSIG5.
  - Bezier curve sets can now be ray traced, which allows for direct modeling of some vegetation (e.g., grass blades).
  - Improvements have been made to shadow ray performance.
- Temperature Prediction Improvements
  - The iterative Balfour model has been improved to reduce noise and mitigate stepping artifacts in thermal shadows.
  - THERM is under active development, but is now supported in DIRSIG5.
    
    All materials currently use 4 hours of history (adaptive history under development).
  - THERM parameter maps are now supported in DIRSIG5.
- ChipMaker Improvements
  - The plugin was updated to leverage the new scene tagging feature to facilitate a new workflow that allows targets and backgrounds to be combined on-the-fly.
  - This introduces a fundamentally new way to generate training data by combining many targets and backgrounds.
- Graphical User Interface Improvements
  - DIRSIG has been upgraded to use Qt6 on all platforms, which will support future UI development.
  - The run-time output of DIRSIG can now be routed to an output file from the run dialog or saved after the fact from the right-click menu in the output panel.
  - Items in the component browser may now be deleted via the right-click menu.
  - For DIRSIG5 simulations, a scene recompile can now be triggered from the run dialog.
- Improved pseudo random number generation (RNG)
  - The internal RNG handling was refined to reduce artifacts and improve performance.
- New Image Analysis/Conversion Tool
  - The new image_tool program was introduced as a replacement for envitopnm and image_analyze utilities.
  - It is intended to serve as a tool to interact with DIRSIG output images, for converting them and performing some common analysis tasks.
  - Both envitopnm and image_analyze are now deprecated and will be removed in a future release.
- Improved Raster Image Handling
  - A new class of plugins was introduced to handle raster image reading, which allows DIRSIG’s image reading capabilities to be extended.
  - The ENVI image plugin has yielded significant runtime improvements when loading these image file types in scene2hdf and image_tool.
  - This new plugin class will (eventually) allow users to add support for additional formats/remote storage of input image files.
- Non-raster source truth has been expanded to improve traceability.
- The makewth.py tool has been updated with more international coverage.
- The object_tool utility can now read ModelMan FACET files.
Demonstrations
- The thermal demos have been updated to be reflect DIRSIG5 compatibility.
  - The MappedTherm1 demo is now compatible with DIRSIG5.
  - The Balfour2 and Thermal1 demos were both improved.
- The PrimitiveObjects2 and Pilings1 demos now work with DIRSIG5 due to the expanded built-in (aka "primitive") support.
- The TimeDelayedIntegration1 demo was added to highlight the TDI functionality in the BasicPlatform plugin.
Bugs
- Fixed an issue where RGB map reflectance curves went to 0 outside the visible instead of using flat extrapolation. Use of RGB maps is not recommended outside of visible simulations.
- Fixed a few issues in make_adb relating to precision, angle ranges and the fast sky mode.
- Fixed an issue with multiple scenes defined using tie points.

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DIRSIG5 2021.27

Features
- Support for a 5-parameter lens distortion model was introduced to the pinhole camera approach used in the BasicPlatform sensor plugin. See the new Distortion1 demo for an example.
- Improvements to the SpiceEphemeris plugin:
  - The user can now override the default SPK (DE-420 ephemeris), PCK (planetary constants) and LSK (leap second) kernel files used by SPICE in this plugin via the JSIM configuration.
  - The Sun/Moon position update notifications generated by the plugin was improved. Although the plugin still updates the position of the Sun and Moon for every temporal state change (e.g. image frame), the user can now control how often update messages are sent to the console output (see the update_delta variable in the JSIM configuration).
- Boundary layer meteorological data (aka weather) support in DIRSIG5 has been migrated into a new set of plugins.
  - The new NSRDB weather plugin provides a vastly improved option compared to the old THERM weather plugin.
- The fourcurve_builder companion tool for the FourCurveAtmosphere plugin is now MPI-enabled for users that want to construct alternative databases using large numbers of MODTRAN simulations.
Demonstrations
- New Demos
  - Distortion1 is a demo showing how to use the 5-parameter lens distortion model in the BasicPlatform sensor plugin.
  - WeatherPlugins1 is a demo showing how to configure various weather plugins in DIRSIG5.
Bugs
- Fixed a bug where the FlexMotion model used for BasicPlatform did not deal with parallel line-of-sight (LOS) and constrain vector cases.
- Fixed a bug where the default body quaternion in the FlexMotion model was not properly initialized.
- Fixed a bug in DIRSIG4 where the self-emission was lacking a cosine term for the view angle.
- Fixed a bug where the scene compiler would decouple a bump map from geometry that is also assigned a material map.

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DIRSIG5 2021.13

Release Packaging
- DIRSIG5 releases for either OpenMPI and MPICH are now available (previously only OpenMPI builds were produced).
Scene Compilation
- The scene2hdf tool was completely rebuilt from the ground up to eliminate the DIRSIG4 code that it was previous based on. The new compiler is significantly faster and uses less memory for some of the random fill instance mechanisms. For more details, please consult the update scene2hdf manual.
- Coinciding with the scene2hdf rewrite, the compiled scene format was overhauled. This change in format does break backward compatibility, so scenes that were compiled with previous releases will need to be recompiled.
- The new compiled scene format now supports the propagation of material specific temperature models through material and mixture maps.
Features
- LADAR/LIDAR
  - In the previous release this modality was considered to be experimental in DIRSIG5. This modality has been extensively exercised during the last development cycle and is considered to be operational in DIRSIG5.
  - These simulations can now be run with the MPI-enabled versions of DIRSIG5, but require the user to use the Unique Frame per-Process (UFP) scheduling mode.
- "Four Curve" Atmosphere Plugin
  - The lower fidelity but physics-driven FourCurveAtm atmosphere plugin was updated to capture azimuthal variances in path radiance.
- New Ephemeris Plugins
  - The ephemeris models responsible for computing the solar and lunar geometry as a function of time were migrated from shared components in the atmosphere plugins to stand-alone plugins. More information about the available ephemeris plugins can be found here.
Graphical User Interface
- The simple capture method interface in the Platform Editor now gives the user access to change the output data type, including integer data types. Note that the unsigned integer types require the user to use the channel gain and bias mechanism, data-driven array amplification mechanism, etc. options to scale the radiometric values computed by the model into integer values. The currently supported data types include:
  - 64-bit floating point (aka double, the default)
  - 32-bit floating point (aka single)
  - 32-bit unsigned integer (aka uint32)
  - 16-bit unsigned integer (aka uint16)
  - 8-bit unsigned integer (aka uint8)
Demonstrations
- Improved Demos
  - Indoors1 is demo that focuses on multi-bounce illumination effects from interior user-defined sources and external atmospheric sources. This demo was updated to feature a more complex scene that highlights the efficient, multi-bounce light transport in DIRSIG5.
  - LidarUserPulse1 is a demo that shows how to use a user-defined temporal pulse profile in a lidar transmitter.
- New Demos
  - LidarRetro1 is a demo that reproduces the expected strong return from a retro (corner) reflector with a LIDAR system.
  - SphericalCollector2 is demo that shows how to use the SphericalCollector sensor plugin to emulate an optical goniometer than can quickly collect BRDF type measurements of complex surfaces.
  - MacbethColorChecker1 is a demo that contains a bundled object of the industry standard Macbeth Color Checker.
  - TriBar1 is a demo that contains a bundled object of the industry standard USAF Resolution Target (sometimes referred to as the USAF "tri-bar" target).
Bugs
- Fixed a bug where the LAS point cloud writer did not include the "GeoKeyDirectoryTag" variable length record, which would upset some LAS point cloud readers.
- Fixed a bug where high-standoff platform motion was not correctly interpolated for small time scales.

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DIRSIG5 2020

Starting in mid-2020, the DIRSIG releases moved from the Major.Minor.Revision naming scheme to a date-based naming scheme. The version is now identified by a Year.Week.Update and the short hash from our GIT repository.

At this time, DIRSIG5 releases come bundled with the latest DIRSIG4 executable. DIRSIG4 development has ceased, but major bugs are being addressed for the time being until the capabilities planned for migration into DIRSIG5 are completed.

DIRSIG5 2020.43

Features
- General
  - The scene2hdf tool now has an explicit option to specify alternative spectral sampling for the compiled scene via an external file.
  - The BasicAtmosphere plugin now correctly handles internal (embedded) weather data in the .atm file.
  - Improved the support for the built-in image viewer to display unsigned 8-bit, 16-bit and 32-bit integer data types.
  - Major improvements for assigning volumetric properties to primitive (built-in) geometry in DIRSIG5. See the updated ExtinctionProp1 demo for an example.
  - Introduction of "bundled materials", which allows you to create individual files that contain complete material descriptions. Centralized collections of these material descriptions can be created and then imported into multiple material database file for a scene or object bundle. See the new BundledMaterials1 demo for an example.
- LADAR/LIDAR
  - This is the first public release of DIRSIG5 with lidar support. It should still be considered experimental but all the lidar demos are generally working at this time. Improvements in performance, the back-end detector models, etc. are still ongoing.
Demonstrations
- The DIRSIG4 and DIRSIG5 demos in the main demo index has been merged into a single set. The D4 and D5 compatibility "badges" with each demo indicate which version of DIRSIG is supported.
- Improved Demos
  - The ExtinctionProp1 was updated to better demonstrate assigning volumetric properties to primitive (built-in) geometry in DIRSIG5. Note, this demo is no longer compatible with DIRSIG4.
- New Demos
  - ColorFilterArray1 is a demo that shows how to use the color filter array (CFA) options built into the BasicPlatform plugin, including Bayer and Truesense patterns.
  - BundledMaterials1 is a demo that shows how to create and use "bundled materials".
  - LidarUserBeam1 is a lidar demo that shows how to incorporate a user-defined spatial (transverse) beam profile.
  - LidarMultiStatic1 is a lidar demo that shows how to model a multi-static (multi-vehicle) collection scenario. It features a single transmitter and two receivers distributed on three separate vehicles.
Bugs
- Fixed a bug where the image filenames in the dry run output did not match those that would be produced during the simulation.
- Fixed a bug where a platform staring at a location would appear to "bounce" due to a problem in the dual quaternion screw linear interpolation (ScLERP) routine when the differences in rotation are small from entry to entry.
- Fixed a bug with the FlexMotion waypoint orientation engine and Euler angle and quaternion orientation engines when a single data entry was provided.
- Fixed a bug related to parsing an optional external spectral sampling file for the scene2hdf utility.
- Fixed a bug where the DIRSIG5 material index truth is off by 1 compared to DIRSIG4 and the material_report.txt.
- Fixed a bug where the emissive objects where being reflected by surfaces with zero reflectance.
- Fixed a bug when using the --capture option with a multi-focal plane sensor with co-temporal (equal) capture times in the BasicPlatform plugin.
- Fixed a bug with inconsistent capture counts for non-zero length tasks.
- Fixed a bug that addresses the correct importing/storing/loading of the internal (embedded) weather data in the .atm file by the GUI.
- The origin of rays for DIRSIG4 is now the focal point of the camera (matches DIRSIG5 BasicPlatform plugin, Maya, etc.) rather than the focal plane.
- The graphical material editor was incorrectly saving SimpleReflectance material properties to the .mat file.

Review all resolved issues in Bugzilla.

DIRSIG 4.7

DIRSIG 4.7.5.17770

Release Date: Thu Jun 15 18:48:18 EDT 2018

General
- Improvements to time precision management within the motion models.
- Improvements to tape5 reading/writing.
  - Verified against 95+ tape5 examples included with MODTRAN6 (except local plume examples, which would be invalid anyway).
- The Atmosphere Editor was updated to provide access to configuring a fixed lunar ephemeris (only access to the solar ephemeris was provided before).

Release Notes

DIRSIG5 2023

DIRSIG5 2023.52

DIRSIG5 2023.12

DIRSIG5 2022

DIRSIG5 2022.48

DIRSIG5 2022.12

DIRSIG5 2021

DIRSIG5 2021.42

DIRSIG5 2021.40

DIRSIG5 2021.27

DIRSIG5 2021.13

DIRSIG5 2020

DIRSIG5 2020.43

DIRSIG 4.7

DIRSIG 4.7.5.17770

DIRSIG 4.7.4.17540

DIRSIG 4.7.3.17195

DIRSIG 4.7.2.16784

DIRSIG 4.7.1.16605

DIRSIG 4.7.0.16452

DIRSIG 4.6

DIRSIG 4.6.3.15676

DIRSIG 4.6.2.15518

DIRSIG 4.6.1.15063

DIRSIG 4.6.0.14842

DIRSIG 4.5

Release 4.5.4.13875

Release 4.5.3.13312

Release 4.5.2.13188

Release 4.5.1.12800

Release 4.5.0.12124

DIRSIG 4.4

Release 4.4.4.11164

Release 4.4.3.10639

Release 4.4.2.9954

Release 4.4.1.8286

Release 4.4.0.7420