htsky

Load and structure a vertically stratified atmosphere
git clone git://git.meso-star.fr/htsky.git
Log | Files | Refs | README | LICENSE

commit 5384b6c8ca7da2f156655e87a83025cf499a56e8
parent 2e4eb5265cfc4875f8e1f5afbcb98d18cc1f9466
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Fri, 21 Feb 2020 12:49:03 +0100

Update the library overview in README.md

Diffstat:
MREADME.md | 45+++++++++++++++++++++++++++++++--------------
1 file changed, 31 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md @@ -6,41 +6,58 @@ atmospheric gas mixture is loaded from a loaded from data stored with respect to the [HTCP](https://gitlab.com/meso-star/htcp/) fileformat. The optical properties of the clouds are finally retrieved from a -[HTMie](https://gitlab.com/meso-star/htmie/) file. Once loaded, the sky -properties (scattering or absorption coefficient, phase function, etc.) can -then be retrieved through functions compatible with the -[Star-MTL](https://gitlab.Com/meso-star/star-mtl/) specification. Consequently -one can use this library as a Star-MTL program describing a semi-transperent -material compatible with the Star-MTL fileformat. +[HTMie](https://gitlab.com/meso-star/htmie/) file. Once provided, the clouds +can be repeated infinitely into the X and Y dimension. + +HTSky relies onto the [Star-VX](https://gitlab.com/meso-star/star-vx) library +to build space partitioning data structures upon raw sky data. These structures +can then be used in conjunction of null-collision algorithms to accelerate the +tracking of a ray into this inhomogeneous medium, as described in [Villefranque +et al. +(2019)](https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018MS001602). +These accelerating structures are built with respect to an optical thickness +criterion whose threshold is user defined. One can also fix the maximum +resolution of the structures in order to constraint their memory consumption. +Even though the building itself of the structures is quite efficient, computing +their underlying data from the input files can be time consuming. So, once +built, these structures can be stored into a file to drastically speed up the +subsequent initialisation steps of the same sky. We point out that this file is +valid as long as the provided HTGOP, HTCP and HTMie files are the ones used to +build the cached structures. If not, an error is returned on sky creation. + +Note that this library provides functions compatible with the +[Star-MTL](https://gitlab.Com/meso-star/star-mtl/) specification. Consequently, +HTSky can be use as it, to describe a semi-transparent inhomogeneous medium in +a Star-MTL file. ## How to build This library is compatible GNU/Linux 64-bits. It relies on the [CMake](http://www.cmake.org) and the [RCMake](https://gitlab.com/vaplv/rcmake/) packages to build. It also depends -on the -[HTCP](https://gitlab.com/meso-star/htcp/), +on the [HTCP](https://gitlab.com/meso-star/htcp/), [HTGOP](https://gitlab.com/meso-star/htgop/), [HTMie](https://gitlab.com/meso-star/htmie/), [RSys](https://gitlab.com/vaplv/rsys/) and [Star-VX](https://gitlab.com/meso-star/star-vx/) libraries, and on -[OpenMP](http://www.openmp.org) 1.2 to parallelize its -computations. +[OpenMP](http://www.openmp.org) 1.2 to parallelize its computations. If the +[Star-MTL](https://gitlab.com/meso-star/star-mtl) library is found, HTSky +will provide functions compatible with the Star-MTL specification. First ensure that CMake is installed on your system. Then install the RCMake package as well as the aforementioned prerequisites. Finally generate the project from the `cmake/CMakeLists.txt` file by appending to the `CMAKE_PREFIX_PATH` variable the install directories of its dependencies. The resulting project can be edited, built, tested and installed as any CMake -project. Refer to the [CMake](https://cmake.org/documentation) for further -informations on CMake. +project. Refer to the [CMake documentation](https://cmake.org/documentation) +for further informations on CMake. ## License Copyright (C) 2018, 2019 Centre National de la Recherche Scientifique (CNRS), -Université Paul Sabatier <contact-edstar@laplace.univ-tlse.fr>. +Université Paul Sabatier (<contact-edstar@laplace.univ-tlse.fr>). Copyright (C) 2018, 2019, 2020 [|Meso|Star](http://www.meso-star.com) -<contact@meso-star.com>. HTSky is free software released under the GPL v3+ +(<contact@meso-star.com>). HTSky is free software released under the GPL v3+ license: GNU GPL version 3 or later. You are welcome to redistribute it under certain conditions; refer to the COPYING file for details.