As you all know, a lot of our ideas for content here in the blog come from real life cases that we solve on a daily basis. We’re always out to harvest information so that we may spread the knowledge to our users. This case started out normally enough – honestly, I don’t even remember the topic. But while working with the drawing, I came across something that made my hair stand up, and I figured you should know about it.
As with most drawings, I was searching for the problem area that the customer reported. This was one of those drawings where the entire design was in one drawing – I really hope I don’t have to tell you how bad an idea this is. Just as I expected, there was a LOT of “stuff” in this drawing – hatches, labels galore, etc. To make sense out of the confusion, I needed to clean it up a bit, so I decided it was time to turn off some layers. As I went into the layer manager, I found out part of the problem – almost 7,000 layers! No wonder the drawing was a bit laggy (that’s a technical term, by the way…) To see if I could reduce the number of layers a bit, I started investigating. My investigation turned up a common mistake that I used to make many many releases ago, so I’ll share it with you.
Follow the link to see what could have created this many layers, and how to avoid that issue in the future.
Let’s take a look at the drawing settings dialog, particularly the Object Layers tab. Here, you will find object names, layers, then a modifier and value column. There’s a “secret” that is a holdover from the Land Desktop days (well, it’s not really a secret – the tip at the bottom of the dialog tells you all about it) that allows you to put an asterisk * as a modifier for a layer, which will automatically add that object name to the layer.
Let’s break down how this works. Let’s say that your layer for your surfaces is C-TOPO. If you put a suffix modifier of an asterisk, your surfaces will each go on separate layers. For example, your EG surface will be on layer C-TOPO-EG. Your FINAL surface will go on layer C-TOPO-FINAL. Get the picture? This can be a very effective way of managing objects via layers, but it can quickly get out of hand.
To illustrate how this can get out of hand, let’s think big – let’s think of objects that get created in mass quantites. Sections, anyone? Section views? Sample lines? What people may not realize is that each object mentioned above gets an individual name! Why is this important? Because every item with an individual name gets an individual layer upon object creation if you’re using the asterisk modifier! Are you starting to see how this can get out of hand? Let me show you an example:
You have a corridor that is 1,000 feet long, and you cut sections every 50 feet. Given a sample line at the beginning of the corridor, that’s 21 sample lines. Let’s say you sample the corridor top surface, EG, and datum surface. That’s 3 sections per sample line. Each sample line has labeling. Each section has labeling. If you’re counting, we’re up to 189 individually named objects, and we haven’t even begun section view labeling or throwing pipe networks into the section views. If you have all those object types set to use an asterisk modifier, that’s 189 extra layers at a bare minimum.
I’ll do you one better…let’s say you made a mistake with your section views and you had to erase all of them and create them again. Do we start over with the naming? No – each one is set by default to use a unique next counter. That’s another 21 sections, another group of layers. The first layers don’t get deleted, even though they may be vacated.
Again, this simply takes one small subset of civil object types – similar behavior can be found in pipe networks where EVERY pipe has a name and EVERY structure has a name.
What’s the takeaway from this? Feel free to use the asterisk modifier, but be very selective when you do, as it can actually introduce problems you might not want to deal with.