3D mapmodule to Oskari?
Oskari map platform has been lacking the possibility to visualize 3D datasets. Usage of 3D material in geospatial context is growing. The 3D mapmodule has been in Oskari roadmap for a while. So what have the developers been up to?
The National Land Survey of Finland (NLS-FI) has had an ample supply of laser scanning data, collected on a yearly basis from 2008 onwards. Up until recently, however, the data has only been accessible for downloading without an easy online visualization tool. Additionally, through work done in the ongoing National Topographic Database projects within the Paikkatietoalusta (PTA, i.e. Geospatial Platform Project) framework, 3D data displaying buildings will become available in near future.
On with Open Source - choose Cesium
3DVISU project begun in February 2018 and the first task was first of all to decide upon the tested 3D library. The library should also be compatible with Oskari along with a sufficient array of visualization tools for a Proof of Concept type solution. So in line with Oskari's open source code policy, the OpenLayers version of Cesium was chosen. The national INSPIRE geoportal Paikkatietoikkuna, serving as a test environment for Oskari development at the NLS-FI, was chosen to act as a test bed for 3D visualisations.
Visualizing 3D buildings, topographic models and point clouds
During 2018, basic 3D support has been incorporated in the Paikkatietoikkuna geoportal's demo environment. Bare in mind that this site is a for demoing and it might not work accurately all the time.
The 3D window uses a selection of the most common Paikkatietoikkuna tools and functions, but when 3D datasets are in hand it changes the view to 3D when zooming in and tilting the view (ctrl+ mouse).
In the city areas of Helsinki and Tampere, LoD1 class buildings extracted from the PTA database have been visualized on top of a height modelled background map. A couple of exemplary map layers are seen in the right hand images. Terrain with buildings and a height-coloured overview of the Kuopio area, displaying NLS-FI point cloud data.