📊2.2 Data Output

Get3D Mapper software supports the output of multiple data formats, including 3D model data, planar 2D topographic map data, and 3D point cloud data.

2.2.1 3D Model Data

The data formats supported by Get3D Mapper for creating 3D models include OBJ format and OSGB format. Both of the following data formats are supported to be opened in Get3D Viewer software.

①　OBJ (Wavefront OBJect):

OBJ format is a file format for representing 3D geometric objects. It contains information that describes the geometry of a 3D object, and its file consists of polygonal faces that are further defined by elements such as vertices, normals, curves, texture maps, and surfaces etc. An OBJ file is a vector file that is scalable and has no maximum file size limit. Due to its simplicity and readability, it has become a widely used format for exchanging 3D models.

②　OSGB (Open Scene Graph Binary):

The OSGB format is a binary file format in the framework of OpenSceneGraph (OSG), an open source, cross-platform, high-performance 3D graphics toolkit, and OSGB is the file format it uses to store and load 3D models and associated material, texture, and geometry data. The OSGB format uses a binary format and uses compression algorithms and data structure optimization to reduce file size and improve loading performance. This makes OSGB format perform well when dealing with large 3D models and complex scenes, making it an ideal choice for storing and representing 3D scene graphics data.

Overall, OBJ format is mainly used to represent the geometry and texture information of 3D models, while OSGB format focuses on the efficient storage and loading of 3D models, which is especially advantageous when dealing with large and complex scenes. When loading 3D models with Get3D Viewer, it is recommended to use OSGB format to preview the model faster.

2.2.2 3D Point Cloud Data

Get3D Mapper supports the generation of 3D point cloud data converted from 3D models or dense matches in *.las, *.txt, *.asc, and *.e57 formats.

①　.las format (Lidar Aerial Survey) ：

The .las format is a commonly used point cloud data format developed by the U.S. Geographic Survey (USGS) and U.S. partners. It is primarily used to store point cloud data acquired by LiDAR scanners, including geometric information (e.g., coordinates, intensities, etc.) as well as other metadata (e.g., scanning parameters, classifications, etc.) for the point cloud.The LAS file is saved in a binary format consisting of a file header that contains the metadata, and a series of point records that contain information specific to each point.

②　 .txt Format (Text File)：

The .txt format is a simple representation of point cloud data, which saves the point cloud data as a plain text file. In this format, each line usually represents the location and color information of a point, making the data easy to read and process, but may not be suitable for storing large or complex point cloud data.

③　 .asc format (ASCII) .asc format, or ASCII format：

is a text file format. In this format, point cloud data is stored as visual text.The ASC model format was developed by Autodesk to make it easier to exchange 3D data between various 3D modeling software. It makes it simple to transfer and share data between different software platforms.

④　.e57 Format:

The E57 format is an open-source, compact and vendor-neutral format developed by ASTM International's 3D Imaging Data Committee. It uses a combination of binary and XML formats to store data such as that acquired by laser scanners, radar (LADAR), and optical rangefinder cameras (Flash LADAR) and LIDAR images.The content of E57 files is encoded in a hierarchical tree structure using an optimized subset of XML, which allows for the efficient storage of large amounts of binary data, making it ideally suited for the exchange of 3D imaging data. .

Each of these formats has its own features and advantages in point cloud data processing, storage and exchange, and users can choose the appropriate format for their specific needs.

2.2.3 Planar 2D Topographic Data

Mapper supports the generation of planar 2D topographic maps including DOM and DSM.

①　DOM (Digital Orthophoto Map):

It is the image data generated by using the digital elevation model on the scanned and processed digitized aerial film/remote sensing image (monochrome/color), correcting the projection difference pixel by pixel, and then cropping the image data according to the image mosaic according to the range of the image format.The principle of DOM production is to apply the professional geographic information remote sensing software to the original remote image after radiometric correction and geometric correction according to its characteristics. The principle of DOM production is to apply professional geographic information remote sensing software to the original remote sensing image after radiometric correction and geometric correction to eliminate all kinds of aberrations and displacement errors, and finally get the satellite remote sensing digital orthophoto maps that contain geographic information and various topics.DOM has the image with a certain geometric accuracy. DOM has a certain geometric accuracy, complete and full vegetation information, clear and uniform overall color tone, and moderate contrast.

②　DSM (Digital Surface Model)：

DSM is a digital model that represents the elevation information of the ground surface and the objects above it (e.g. buildings, trees, utility poles, etc.). It includes the elevation data of the ground surface and these obstacles, so it can more realistically reflect the shape of the ground surface.DSM can be used to produce 3D models, remote sensing analysis and many other applications.