2019 FOSS4G Bucharest Talks speaker: Lutra Consulting
Mesh: GIS data beyond raster and vector
Most real world features can be presented as vector or raster layers. In open source world, GDAL provides a comprehensive set of tools to interact with such datasets. But vector or raster is not always a suitable description of real world features. Data from oceanography, metrology, hydrology, etc often have multiple components at each location on an irregular structured mesh.
A mesh can a collection of vertices, edges and faces in 2D or 3D space:
- vertices - XY(Z) points (in the layer's coordinate reference system)
- edges - connect pairs of vertices
- faces - sets of edges forming a closed shape - typically triangles or quadrilaterals (quads), rarely polygons with higher number of vertices
<img alt="Example of mesh" src="https://user-images.githubusercontent.com/193367/38030812-f6c4f174-3299-11e8-91ed-30684ceae715.png" />
Mesh gives us information about the spatial structure. In addition to the mesh we have datasets that assign a value to every vertex. For example, ice cap thickness at particular moment of time. A single file may contain multiple datasets - typically multiple quantities (e.g. water depth, water flow) that may be varying in time.
Input: A touch friendly mobile app for data collection
Data collection is an essential part of most GIS users. There are several mobile apps (open source and proprietary) which can be used carry out such tasks.
QGIS Quick library has become a part of the official QGIS project and it adds the possibility to create custom mobile apps. Just like plugin architecture for desktop QGIS allows great flexibility to introduce custom functionality, QGIS Quick library provides similar groundwork for mobile mapping apps.
Input a free and open source mobile app has been developed, leveraging on the new QGIS Quick library.
QGIS 3D: current state and future plans
QGIS 3D native rendering has been introduced since QGIS 3.0, thanks for the funding we received from QGIS.org. Over the past couple of years, we have added several features and enhancements.
QGIS 3D can now render raster, vector and mesh layers. Depending on the data or geometry type, there are various method of visualising and styling the 3D data. In this talk, we will go through:
- Supported 3D data formats
- Sources (repositories/download sites and services) where to get 3D data from
- Global and per layer configuration options
- 3D rendering options (symbology/styling, rule based renderer)
- Thematic maps with data-defined extrusions and the rule-based renderer
- Drape 2D-data to 2.5d with Processing and a DTM
- Animating a movie based on key frames
- Printing 3D in a layout
The features we'd like to develop in future will include:
- Rendering of point cloud
- Enhancing the 3D rendering performance
- Support for globe