Heidelberg LiDAR Operations Simulator ++
HELIOS++ is a general-purpose software package for simulation of terrestrial, mobile and airborne laser scanning surveys written in C++11. It is developed and maintained by the 3DGeo Research Group at Heidelberg University.
Precompiled versions for Windows and Ubuntu (other Debian might also work, but you need to install dependencies manually) are available under releases.
As a starting point, please consult the wiki. We suggest you take the "first steps" tour to get to know the core concepts of the software.
Official website: https://uni-heidelberg.de/helios
For scientific and collaboration inquiries please contact the HELIOS++ team at helios@uni-heidelberg.de
We have also published two papers on HELIOS++. If you use HELIOS++ in a scientific context, please cite one of the following:
- General description of the framework:
Winiwarter, L., Esmorís Pena, A., Weiser, H., Anders, K., Martínez Sanchez, J., Searle, M., Höfle, B. (2022): Virtual laser scanning with HELIOS++: A novel take on ray tracing-based simulation of topographic full-waveform 3D laser scanning. Remote Sensing of Environment, 269, doi:10.1016/j.rse.2021.112772
BibTeX:
article{heliosPlusPlus,
title = {Virtual laser scanning with HELIOS++: A novel take on ray tracing-based simulation of topographic full-waveform 3D laser scanning},
journal = {Remote Sensing of Environment},
year = {2022},
volume = {269},
issn = {0034-4257},
doi = {https://doi.org/10.1016/j.rse.2021.112772},
url = {https://www.sciencedirect.com/science/article/pii/S0034425721004922},
author = {Lukas Winiwarter and Alberto Manuel {Esmorís Pena} and Hannah Weiser and Katharina Anders and Jorge {Martínez Sánchez} and Mark Searle and Bernhard Höfle},
keywords = {Software, LiDAR simulation, Point cloud, Data generation, Voxel, Vegetation modelling, Diffuse media}
}
- High performance computing:
Esmorís, A. M., Yermo, M., Weiser, H., Winiwarter, L., Höfle, B., Rivera, F. F. (2022): Virtual LiDAR Simulation as a High Performance Computing Challenge: Toward HPC HELIOS++. IEEE Access, 10, doi:10.1109/ACCESS.2022.3211072
BibTeX:
@Article{Esmoris2022_HPC-HELIOS,
author={Esmorís, Alberto M. and Yermo, Miguel and Weiser, Hannah and Winiwarter, Lukas and Höfle, Bernhard and Rivera, Francisco F.},
journal={IEEE Access},
title={Virtual LiDAR Simulation as a High Performance Computing Challenge: Toward HPC HELIOS++},
year={2022},
volume={10},
issn = {2169-3536},
pages={105052--105073},
doi={https://doi.org/10.1109/ACCESS.2022.3211072},
url={https://ieeexplore.ieee.org/document/9906068}
}
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HELIOS++ can be invoked with following syntax:
helios --help
Show the help for helios++ usage
helios --test
Perform necessary tests to check everything works as expected
helios --version
Show the HELIOS++ version details
helios <survey_file_path> [OPTIONAL ARGUMENTS]
Perform requested simulation.
NOTICE specifying the path to the survey specification file is mandatory
Available general OPTIONAL ARGUMENTS are:
--assets <directory_path>
Specify the path to assets directory
--output <directory_path>
Specify the path to output directory
--splitByChannel
Enable the one-file-per-device writing mode when using a
multi-channel scanner.
--writeWaveform
Specify the full waveform must be written
--calcEchowidth
Specify the full waveform must be fitted
--fullwaveNoise
Enable random noise at full waveform computation
--fixedIncidenceAngle
Sets incidence angle to exactly 1.0 for all intersections
--seed <seed>
Specify the seed to be used for randomness generation.
The seed can be an integer number, a decimal number or a timestamp
string with format "YYYY-mm-DD HH:MM:SS"
--gpsStartTime <string>
Specify the GPS start time. By default it is an empty string "",
which means using current system time.
It can be given as both, a posix timestamp as string or a datetime
string with format "YYYY-MM-DD hh:mm:ss"
--lasOutput
Specify the output point cloud must be generated using LAS format
--zipOutput
Specify the output point cloud and fullwave must be zipped
--lasScale
Specify the scale factor used to generate LAS output
--parallelization <integer>
Specify the parallelization strategy. Where 0 leads to a simple
static/dynamic chunk based strategy and 1 leads to a warehouse
based strategy
-j OR --njobs OR --nthreads <integer>
Specify the number of simultaneous threads to be used to compute
the simulation
If it is not specified or it is specified as 0, then all available
threads will be used to compute the simulation
--chunkSize <integer>
Specify the chunk size. If it is positive, it will be used as a
fixed size but if it is negative the absolute value will be used
as starting size of a dynamic chunk-size based strategy.
--warehouseFactor <integer>
The number of tasks in the warehouse would be k times the number
of workers. Greater factor implies less probability of idle cores
at expenses of greater memory consumption.
--rebuildScene
Force scene rebuild even when a previosly built scene is available
--kdt <integer>
Specify the type of KDTree to be built for the scene.
Using 1 leads to the simple KDTree based on median balancing,
2 to the SAH based KDTree, 3 for the SAH with best axis criteria
and 4 (the default) to the fast approximation of SAH
--kdtJobs <integer>
Specify the number of threads to be used for building the KDTree.
Using 1 forces sequential building, 0 as many threads as available
cores and n>1 implies using exactly n threads.
Using more cores than required might degrade performance due to
overhead.
--kdtGeomJobs <integer>
Specify the number of threads to be used for upper levels of
KDTree building.
By default it is 0, which means as many jobs as --kdtJobs
Using 1, means no geometry-level parallelization will be used when
building the KDTree
Using >1, means exactly n threads will be used at geometry-level
KDTree building
--sahNodes <integer>
Either how many nodes must be used by the Surface Area Heuristic
or the number of bins for the fast approximation of SAH
--disablePlatformNoise
Disable platform noise, no matter what is specified on XML files
--disableLegNoise
Disable leg noise, no matter what is specified on XML files
Available logging verbosity OPTIONAL ARGUMENTS are:
--silent
Nothing will be reported
-q OR --quiet
Only errors will be reported
-vt
Time and errors will be reported
-v
Errors, information and warnings will be reported
-vv OR -v2
Everything will be reported
IF NONE IS SPECIFIED
Errors and information will be reported by default
Available logging output mode OPTIONAL ARGUMENTS are:
--logFile
Reports will be emitted through standard output and output file
--logFileOnly
Reports will be emitted through output file only
IF NONE IS SPECIFIED
Reports will be emitted through standard output only
Unzip compressed output:
--unzip <input_path> <output_path>
When helios++ is executed with --zipOutput flag, output files are
compressed. They can be decompressed using --unzip.
The path to a readable helios++ compressed output file must be
given through input path.
The path to a writable file/location must be given through
output path.
The demo simulation can be executed as follows:
LINUX
run/helios data/surveys/demo/tls_arbaro_demo.xml
WINDOWS
run\helios.exe data/surveys/demo/tls_arbaro_demo.xml
Build instructions for advanced users and developers are available here.
For running pyhelios, we suggest setting up a seperate conda environment. After downloading one of the releases or building from source, run
conda env create -f conda-environment.yml
in the base environment of your conda installation, while you are in the HELIOS++ root directory. Then run
conda activate pyhelios_env
to activate the environment and
python pyhelios_demo\helios.py data\surveys\toyblocks\als_toyblocks.xml
to run a demo survey including visualisation.
Not a fan of the command line? Check out the graphical helios launcher by Jonathan Schellhase at github.com/dg-505/helios-launcher. You can select the HELIOS++ installation directory and the survey path, and set additional options in a text field. Clicking the "Run" button will execute the survey and display the output in a text window. Another button opens the output folder for you. As simple as that.
Since December 2019, the Blender2Helios add-on by Michael Neumann allows easy conversion of Blender scenes to HELIOS++ scenes. Semantic labels are also supported and can be combined easily by using collections in Blender.
Our two own Blender add-ons allow you to export animated Blender scenes to HELIOS++, providing an interface to probably the most popular free and open source 3D software. dyn_b2h exports a Blender animation to a dynamic HELIOS++ scene with rigid motions, while multi_epoch_b2h exports static snapshots of the animation, creating a time series of HELIOS++ scenes. The add-ons include exporting scene part OBJ files and writing scene XML files, and can also be used for static scenes. Download the add-ons from the GitHub repo and get started!
Our QGIS Plugin AEOS embeds HELIOS++ into one of the most widely used GIS applications. It enables the creation of HELIOS++ surveys using QGIS vector and raster layers and the subsequent execution of the surveys, with direct availability of the results in the form of a QGIS point cloud layer. Crucially, it allows for instant visualisation of both the input and output of a HELIOS++ simulation within a familiar user interface, thereby greatly improving ease of use. In Greek mythology, Aeos is the name of one of the four horses that pulls Helios' fiery chariot accross the sky. Feel free to download AEOS from its own GitHub repo and add it to your arsenal of QGIS plugins now!
See LICENSE.md