ArcSDE CAD Client #3
Well our daughter, baby Evie, had a short run at her new “big” bed, but it proved a little too much for her to handle at this time. Our 2 year old had been climbing out of her crib and we thought it might be time for her to move to a "child-size bed". However, she didn’t handle her new found freedom very well. With her liberty she found it difficult to settle down and sleep. Ransacking her room seemed to be a more pressing pursuit than sleeping… late at night till early in the morning. This weekend we discovered the “crib tent”, this is a euphemism for a crib lid; an arching mesh cover that transforms you baby’s crib into a... well... cage. Despite one night of vocal opposition to returning to the crib she now sleeps soundly again within the comfortable confines of her smaller nighttime domain.
Sometimes the freedom and power of an all encompassing software solution can leave you floundering as you attempt to come to grips with its far reaching implications. I like CAD Client for its targeted simplicity. If the ArcSDE CAD Client fits your workflow it is one of those applications that you can use, like a hammer, to get something done. It doesn’t drive screws very well, but if you got a nail it can do the job.
When storing CAD data into ArcSDE simple feature layers, CAD Client will always be creating ArcSDE features. Other GIS applications that can read ArcSDE data, will be able to access the ArcSDE feature representations stored from the geometry of my CAD data. As part of the data storage process CAD Client converts CAD entity geometry into ArcSDE feature geometry. In addition to the geometry, it also has the ability to store the CAD entity graphic properties, such as COLOR, LAYER, LINESTYLE, etc… as tabular ArcSDE feature attributes. ArcSDE CAD Client also has the ability to store a binary copy of each CAD object in a special column in ArcSDE. The exact binary copy of a CAD object stored inside ArcSDE is often called CAD BLOB or CAD Object storage in CAD Client. Unlike the compulsory creation of ArcSDE features for each CAD object, CAD BLOB storage is optional.
Storage of the CAD BLOB Object is useful, because when working inside the CAD host (AutoCAD/Microstation) using CAD Client you can choose to RETRIEVE CAD BLOB data that is stored in ArcSDE layers rather than the ArcSDE feature version of the data. Other GIS applications will not understand the CAD BLOB data, which is why it always creates an ArcSDE feature when CAD data is stored.
ArcSDE CAD Client can be used as a way to create a CAD basemap of CAD BLOB objects in ArcSDE for retrieval back into CAD. The resulting data is also accessible by other GIS application that read the ArcSDE feature versions of that same data.
I will discuss more about the methods of data storage later in this series. Let me just say for now CAD Client stores features not drawings. For this reason, although some have tried to use it as such, CAD Client makes a better basemapping system than it does a CAD document managment system.
CAD BLOB data storage inside ArcSDE-managed data layers is a unique and useful feature of CAD Client that distinguishes it from any other ESRI, Bentley or Autodesk GIS interoperability CAD client applications.