OBJ is a geometry definition file format (.obj extension) first developed by Wavefront Technologies for its Advanced Visualizer animation package.
The OBJ file format is a simple data-format that represents 3D geometry alone — namely, the position of each vertex, the UV position of each texture coordinate vertex, vertex normals, and the faces that make each polygon defined as a list of vertices, and texture vertices.
Vertices are stored in a counter-clockwise order by default, making explicit declaration of face normals unnecessary. OBJ coordinates have no units, but OBJ files can contain scale information in a human readable comment line.
PRC (Product Representation Compact) is a 3D file format that can be used to embed 3D data in a PDF file.
This highly compressed format facilitates the storage of different representations of a 3D model. For example, you can save only a visual representation that consists of polygons (a tessellation), or you can save the model's exact geometry (B-rep data). Varying levels of compression can be applied to the 3D CAD data when it is converted to the PRC format using Adobe Acrobat 3D.
A CAD file is an output of a CAD software, containing key information about the designed object: its geometry and topology representation, 3D model hierarchy, metadata, and visual attributes depending on the format of the file.
Read moreIn the ninth part of the series, we take a look at the effectively standard format for 3D graphics
Read moreCAD Exchanger imports and tesselates FBX, glTF, OBJ, PLY, and STL files, making them ready for further optimization by RapidCompact.
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