Introduction to GKS-3D

GKS-3D is a pure super-set of GKS designed to handle 3D graphics in a compatible way. That is to say, a 2D application written to the GKS standard is guaranteed to run in a GKS-3D environment without change. However, apart from the usual GKS functions, GKS-3D provides additional ones to handle 3D primitives, 3D input, and 3D viewing. As for GKS, the standard is in multiple parts with the language bindings separate from functional specification. The FORTRAN binding is defined in [7].

All primitives within GKS-3D are deemed to be three dimensional. Thus, although an application using GKS-3D may make only 2D function calls, all the 2D primitives will be turned immediately into the corresponding 3D versions inside the package by the addition of a Z coordinate. This has several noticeable effects:

• 2D function calls may be slightly slower than 3D ones (using the same GKS-3D package), as a 2D call will add a Z coordinate and then make the corresponding 3D function call.
• 2D applications running on GKS-3D will take more storage space in WDSS and WISS.
• A 2D picture stored on a 3D metafile will require more space than on a 2D metafile. Also, quite clearly, such a picture could not be re-interpreted by reading the metafile into a GKS (2D) implementation.