This code estimates 3D leaf area density (
- Ground filtering using CSF
- Understory and overstory speration
- Tree crown segmentation
- Crown boundary(alphashape, voxel, ellipsoid, cone) creation
- Leaf area density estimation using pulse tracing, point number, or user-defined LAD, scene LAI.
- 3D scene creation for 3D radiative transfer models (LESS currently)
There are two approaches to use this code, one is directly from LESS, which provides a user interface, the other way is to directly use the python code provided within this repo.
please go to Download LESS to download the latest version of LESS. LESS is a ray-tracing based 3D radiative transfer model, which provides both graphic user interface (GUI) as well as Python SDK to perform 3D radiative transfer simulation over detailed 3D scenes (e.g., forests and city buildings). LESS can simulate bidirectional reflectance factor, multispectral/hyperspectral images, LiDAR waveforms/point cloud, thermal infared images, FPAR, etc. We recommend to install LESS in a path without spaces to avoid some possible issues during simulation, e.g., D:\LESS. (Note: recent LESS versions only support Windows)
Click 【Tools】【3D Object Creation】【3D Forest from LiDAR (ALS)】,then you will get a GUI dialog as follows:
Input the ALS data or UAV data as *.las files. Then you can configure parameters, including crown types to estimate leaf area density, and estimation method.
Specify a out directory, after the execution, you will get a LESS simulation folder under the out diectory, you can use LESS GUI to open the simulation to
do visualization or perform radiative transfer simulations. If you just want to use the estimated paramters, you can refer to the _tmp_ foler, which constains all the obj files that represent
the crown boudaries. lad.txt contains the leaf area density of each shapes, and shapes.txt contains the volume of each shape (the second column), the first column of lad.txt and shapes.txt is the name of the generated obj files within the folder.
You can directly refer to the als2less.py within the code. A more easier way to interprete the parameter setting is also to use the GUI, after an excution, you will find a command line in the output section of the LESS GUI. Then you can copy the code, e.g.,
D:\LESS\app\bin\python\python D:\LESS\app\Python_script\ALS2LESS\als2less.py -i C:\Users\DELL\Desktop\ALS_sample.las -o C:\Users\DELL\Desktop -sim_name sim_proj01 -seg_method watershed -seg_param 4.5 -type alphashape -param 5 -include_understory false -pad_method pulse_tracing -pad_constant 0.8 -total_lai 3.0 -understory_height auto -leaf_angle_dist Spherical -leaf_op leaf_op_name01 -leaf_as_facet false -single_leaf_area 0.01
Please note that if you do not use the python interpreter installed with LESS (e.g., D:\LESS\app\bin\python\python.exe), you will need to install sklearn, CSF, laspy for your own python.