Alternative 2D Representation of 3D Objects, Chunk Type for 2D Alternative Representation
The representation of 3D objects in 2D plan views, is generated by default from the 3D model and its defined edges when the object is loaded i.e. when it is inserted from the catalog. Alternatively, objects can have fixed representations defined in the form of 2D-symbols (*cys files). This fixed representation is allocated to the object over the ‘Alternative 2D representation’ chunk. Objects which contain a chunk for alternative 2D representation, are always automatically represented by this symbol. Working with fixed representations can considerably improve the graphic quality and speed up the loading of 3D elements which contain a lot of edges, as the 2D representation no longer has to be generated.
When using alternative representations of objects, it should be noted that they are automatically scaled according to the exterior dimensions of the 3D object. Therefore, the proportions of the symbol should correspond to those of the 3D object. If the scale of an object with an alternative representation, is later distorted, then the 2D representation is distorted to the same extent. The following illustration shows a table with its automatic alternative representation on the left, and on the right its representation by a symbol added later.