Mesh 3D — Auvergne-Rhône-Alpes — 2021

3D mesh projection Lambert-93/NGF-IGN69 on Montluçon, Moulins, Vichy, Riom, Clermont-Ferrand, Aurillac, Saint-Etienne, Voiron, Gex, Valencia, Vienna and Bourgoin. The Auvergne-Rhône-Alpes Regional Centre for Geographic Information is a resource centre in the field of geographic information. As part of its tasks, the CRAIG must, inter alia, create synergies between actors in order to achieve economies of scale, both material, human and financial in terms of the acquisition of spatial data. CRAIG has launched the production of a dataset to assess the contribution of 3D to the territories. The benefit included a range of data that could be of interest to the territories, namely: — Vertical and oblique aerial shots of 3 and 5 cm resolution — Realisation of orthophotoplans — 3D modeling of urban areas — Acquisition and classification of very high density lidar point clouds and derivatives (MNT, MNS) — Building 3D (LOD 2.2, LOD 3), BIM In total, it is several To of data that have been acquired on a dozen sectors of the Auvergne-Rhone — Alpes region representing an area of almost 500 km². As part of the World Heritage Listing, the municipality of Vichy in the department of Allier has been the subject of special treatment, including the production of vertical and oblique aerial shots up to 3 cm of resolution and a LiDAR lift with a density of up to 500 pts per m². Semantic and MNT data were produced with the Rhino suite from high resolution PVA (nadir and oblique) and high density LiDAR on Vichy and Saint-Etienne. Old Nadir PVAs (from the countryside to make orthos 5 cm) were used to produce 3D meshes on other cities. The perceptual quality of results depends on the recovery of ACPs and whether oblique ACPs are used. The accuracy of the numerical models is 15 cm in planimetry (XY) and 15 cm in altimetry (Z).