How much should I model in ArchiCAD? (Part 1)
In a not-so-recent post I discussed how to intelligently dumb down your output. I stressed that it is important to separate the intelligence of the model from that of the documentation. Add everything you can into the model and then curate what your audience sees. This not only allows you to separate what you need from what your clients need, it also means that at any point in a meeting you can always reveal more. You can act like some magical wizard. You can turn a simple plan into something much more complex. If the conversation turns from generic concepts to hyper specificity, you can snap your fingers and have the ArchiCAD model (which WILL be open and available to explore during your meeting) reveal more and more and more information.
It’s not about what you want, but about what you need
And here we come to one of the most often asked questions by anyone associated with ArchiCAD (or any BIM program). The question can be asked in a number of ways, though there are three primary versions: How much should I model? What should I model? What should I not model?
The answers directly affect everything in the overarching scope diagram that explains the balance between time, quality, and cost. The diagram which represents the balance that must be maintained to be a profitable, viable company. If you want speed and quality, be prepared to pay for it. If you want fast and cheap, be accepting of lower quality. If you want quality at an affordable price, be prepared to wait for it. As BIM users we so often face the danger of not enough money and not enough time. It is not because BIM demands so much time and money, but because we so easily get distracted by the wrong things.
I wish there was a simple answer that I could give you. To say always model X, but never Y. Or just advise to always model everything. But I can’t. Furthermore, if discussions of LOD (Level of Development and/or Level of Detail) are anything to go by, just declaring LOD 200 or 300, etc. doesn’t really answer the question either. What to model is dependent on so many factors, though mostly summed up by time, cost, and quality. What follows can’t possibly cover everything, but hopefully it’ll get discussions going and give you a better framework for your own decision making process when you are faced with this eternal question.
In the rest of this post we’ll look at the first of the three ways to ask the “to model or not to model” question. In a follow up post tomorrow, I’ll tackle the other two versions of this question.
How Much Should I Model?
- How much you should model is dependent on how much you are capable of modeling. Speed and Knowledge: these are the baseline. If your team isn’t very fast in ArchiCAD. If your team isn’t very knowledgeable about building construction. If your team is filled with lots of new users. If your team doesn’t have a robust template at their disposal. Don’t ask or expect them to model everything that a grizzled old veteran typically does.
- Model what affects decisions and details. Ignore what is just fluff. Don’t waste your time modeling detail that is only the purview of a product manufacturer. Focus your modeling on what you are in control of. When you model a window, what matters most is the unit dimensions. What matters least is the profile of the sill or frame. Not only does modeling every fold of the extruded section add to model complexity (and total polygons), it is detail that is rarely seen in drawings, when viewing the 3D model, and gives a misleading POV of what you as a designer can detail to—unless you are working with super high-end and wealthy clients, contractors, and subs… but more importantly, if all the minute detail won’t be seen, it’s a waste of your time.
- Added complexity doesn’t always mean added value. Be aware of polygons. I’ve talked about this before, but as always it’s worth reiterating. Excessive modeling can slow down files. Just because you CAN model something doesn’t mean you SHOULD model something. I am reminded of a story from years ago. I taught a coworker my method of modeling siding using complex profiles. He loved it and went wild. But instead of modeling a simplification of the siding, he modeled every little turn. Instead of a 6″ piece of lap siding having 2 faces exposed, he included air gaps and had probably 8 or 9 faces (some as small as 1/16″ across). His model was super accurate, but also super slow. The added detail provided no extra value and in fact impaired the utility of the rest of his work. If modeling something simply adds more, as much, or almost as much value as modeling it to a more detailed level, model it simply.
- Don’t be a slave to someone else’s approximations. Often times we are working with data from others that is their interpretation of reality. If you are working with this data, it’s okay to simplify it further, assuming it maintains the essence of the real thing. Overly detailed 3rd party Objects are one instance of this, but terrain is the best example. If you are modeling a site, think about doing a 3-segmented contour instead of a complex and compound curve or a zigzagging line with dozens of nodes. The surveyor’s information is just an extrapolation anyways, so why not make your life easier and simplify it down even more. When you set all contours on a Mesh to smooth and show your client the model in 3D they are going to be wowed whether your contours have 100 nodes each or 10. Remember to be wary of curves, and minimize nodes—especially when working with Meshes.
- Remember placeholders. You can always add more detail if need be. One of the most powerful aspects of modeling within ArchiCAD is that it is so easy to replace, refine, and increase (or decrease) the detail of an element. Start as simple as you can, with only the detail you know and need. You can always add more later. Adding too much detail early on can limit your speed later in the process and may give a misleading level of confidence about decisions already made. If you do add a lot of detail early on, remember you can always hide it.
- Always care about craft. When modeling remember craft matters. Lots of sloppy detail is much, much worse than finely done minimalism. Likewise, if you are going to add lots of detail, make sure you are adding that detail as efficiently as possible and avoiding the creation of error messages. And if you do get error messages, get rid of them. The more error messages you get, the less you will be able to model (and have things run smoothly).
I’ll stop here for now. Click here for Part 2 where we’ll discuss this topic from the perspective of what to model and what not to model.
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