Because a world file is based on a specific coordinate system definition (PRJ file), you first must define a spatial reference for the CAD or BIM data either select one from the CAD or BIM File Properties dialog box, or use the Define Projection geoprocessing tool. In such cases, ArcGIS Pro requires an offset file (WLD3) to properly position your BIM data or CAD data. It is not uncommon for BIM or CAD design files to use a relative or local coordinate system rather than a geospatial coordinate system within a model. The two sets of points may be directly related to the model and map coordinates as in the case of adding control points when georeferencing, or the coordinates may be simplified to mathematically define the necessary transformation. The resulting two vectors define how two points within the CAD or BIM model's coordinate space should be offset, scaled, and rotated within the map. The second row defines a second displacement vector and another set of from and to points with the following syntax. The first row defines a displacement vector with a set of from and to points using the following syntax. The information in a world file is comprised of two sets of points. The best CAD, BIM, and GIS workflows attempt to avoid the need for a world file by using geospatial coordinates within the CAD and BIM files themselves. The transformation information is only valid with the matching spatial reference file (PRJ) for which it was created. The points are used to calculate two vectors that define the offset, scale, and rotation of coordinates within the assigned spatial reference. A world file (WLD3) is a text file containing four points that describe a coordinate transformation.
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