Video Tip - How to Trace 2D Drawings to Create Your Model

[Eric Bobrow]

I have prepared a new video tip on a topic that should be of interest to many ArchiCAD users. In this demonstration, I show how to bring in 2D drawings (in this case, DWG files) as a tracing reference to make it easy and fast to create an accurate 3D model.

The video may be viewed here:
http://www.archicadtemplate.com/?page_id=864

At this point, it is about 90 minutes long, and shows every step along the way. I plan to condense it down to focus on the principles and show only the most important steps. Note that for this long version there is a timeline control strip, so you can jump to any point you wish, or replay sections at will.

Here is an outline of the process:

• * Create a new project
  * Import the DWG files into separate Worksheets and coordinate their origin points
  * Set up the Story Levels to correspond to the project heights
  * Use Virtual Trace to reference the ground floor DWG as a background while working on the ground floor plan
  * Move the original MasterTemplate base slabs, elevation and section markers, and gridlines to the vicinity of the traced DWG
  * Set up the wall tool for the proper thickness and height, then trace the outline of the building
  * Repeat for the upper story
  * Place windows in the walls using the plan DWGs as references for location and width
  * Open each of the Elevation viewpoints and correspond the DWG Worksheets for trace reference
  * Adjust window heights, types and glazing patterns to match the original drawings
  * Repeat for the doors, first on plan, then in elevation
  * Draw the first roof piece on plan by tracing over the roof outline from the original drawing
  * Coordinate the height and thickness of the roof in each elevation
  * Use these adjusted settings to create the rest of the roof system on the lower level, then repeat the process for the upper roofs
  * Trim walls to the roofs to clean up the model
  * Adjust some of the windows and doors to have arched tops with bricks above
  * Review the 3D model, elevations and plans, which now correspond beautifully to the original drawings

All of this was done in real time, in 90 minutes!

To be frank, the first time I did this it took between 3 and 4 hours, because I had to become familiar with the project and how the DWGs were organized. The second time it took about 2 to 2 1/2 hours, and then I started over and recorded the process the third time in 90 minutes from start to finish.

In the near future, I will condense this video into a shorter presentation, perhaps 10 - 20 minutes long, and create an article that explains the process.

I look forward to your comments and feedback.

[Anonymous]

Eric,

I skimmed through your video over 30 minutes, what I saw of it was really very useful. It's a process that we regularly go through in practice, most of the jobs I have modelled in ArchiCAD have grown from trace referenced dwgs.

The video is invaluable for our staff who need to learn the ArchiCAD process, while the Experience BIM videos are useful they seem to serve as sales pitches rather than learning tools - relying more on favourites than the entire modelling process.

Can I ask though - would you consider keeping the whole 90 minute video online? Perhaps in addition to a condensed 20 minute video? While the 90 minutes is lengthy for the experienced user, for those who are new to the software it seems to be at a much nicer pace to follow.

Simon

[Eric Bobrow]

Thanks for your positive feedback. I will definitely keep the longer version available so that people who are interested may see the complete step by step.

[TMA_80]

Eric, this is definitely a great "reference" video. thanks.

[Steve Jepson]

I watched for about 20 min. and lost interest. It's too slow. Besides, the entire approach I saw demonstrated is fundamentally wrong in my view.
With an original .dwg to use, there is no need to trace anything. Use Magic Wand!
Model it right in the original .dwg or Copy and Paste things to a fresh ArchiCAD template if you like to use them. Personally, I don’t find templates very useful. I prefer to just copy and paste from similar projects, then tweak as needed.

Perhaps I did not watch long enough to see optional ways of doing the same thing faster.

[Eric Bobrow]

Steve -

Yes, watching someone draw a whole building can be tedious, which is why I plan to condense this down to show and explain the important steps in the process; I'm sure you'll find this more to your liking.

Regarding your comments about using the magic wand to automatically trace the exterior - this sometimes works very well, but I often find that it breaks up walls on either side of windows or doors, or continues walls from exterior to interior, or makes other "mistakes" because of the way it interprets the sequence of lines. It may work in some contexts, but not others, and often requires extensive cleanup. Drawing the outline manually allows me to judge when the wall continues and when it doesn't, and requires less cleanup.

Copying and pasting from a similar project is an excellent approach. It is a quick way to bring in elements that are appropriate for the new design.

The visual favorites that I demonstrated from MasterTemplate were only minimally used in this video because they were not the focus, however they can be an excellent time-saver in other parts of the process. Also, MasterTemplate (and other well thought out templates) can embed a lot of reusable structure to simplify the work of setting up the project Views and Layouts. There is a LOT more to a good template than you can achieve by copying and pasting.

After tracing the plan, the video goes on to demonstrate how to use the Elevation drawings as a background for quickly setting the window and door heights, operation types and glazing patterns, as well as coordinating roofs and trim elements. This method is an excellent way to apply Virtual Trace.

By the way, you can jump ahead in the video to see other parts of the demonstration. I believe you have to wait until the download has reached that point, but once it's in your browser cache, you can jump around at will.

[Anonymous]

Steve,

Just with regards to working with trace reference: we found in practice that when we bring in dwgs, often from surveys, they bring with them a load of unwanted layers.

So we often take dwgs into a new file to refine them, we put all 2D information onto the ArchiCAD layer before bringing them into our model. The trace reference then allows us to screen whether we show text, labels etc. without the need for more layers. The splitter tool has also been very useful to easily read what's been modelled and what's not.

We used to model walls with the magic wand but as Eric said, found we'd spend as much time remodelling any mistakes as we'd saved. Also with large scale projects, like hospitals, working in the dwgs has been problematic. The survey dwgs are often massive and slow ArchiCADs performance considerably. On one particular healthcare job I was working in the dwg, but found everytime I accidentaly clicked on a line of the dwg I would have to wait 5 minutes to then cancel the selection.

I guess it depends on the quality of dwgs you're importing and power of machine you're working on? It's just that we've found on lower end machines ArchiCAD struggles with 2D data more than its native 3D elements, so prefer to keep 2D data in worksheets.

Simon

[Erika Epstein]

Steve,
I think it's great that Eric posted the video. I've seen Eric demonstrate many times at the local user group (he is my local reseller) and have learned a lot from him over the years. There is a lot to learn watching how someone else works.

Often when I go into other offices, people have time and again commented about how just watching me,another person, work is beneficial.

[Anonymous]

Eric wrote:
Regarding your comments about using the magic wand to automatically trace the exterior - this sometimes works very well, but I often find that it breaks up walls on either side of windows or doors, or continues walls from exterior to interior, or makes other "mistakes" because of the way it interprets the sequence of lines.

It also leaves you subject to the accuracy of the imported DWG which is generally not something I am willing to do. It is too easy for a drafter to let things slide under pressure. In 2D AutoCAD if it looks good enough it is good enough (at least to print). One of the worst things in this business is to have a building model that is almost correct. Gross variance is much easier to see (and fix) than 1/64" and 0.002° errors.

[Karl Ottenstein]

I have not watched the video yet ... think I'll wait for the abridged version, but very glad that Eric has done this for the community.

Eric wrote:
Regarding your comments about using the magic wand to automatically trace the exterior - this sometimes works very well, but I often find that it breaks up walls on either side of windows or doors, or continues walls from exterior to interior, or makes other "mistakes" because of the way it interprets the sequence of lines. It may work in some contexts, but not others, and often requires extensive cleanup. Drawing the outline manually allows me to judge when the wall continues and when it doesn't, and requires less cleanup.

I agree completely for all of the reasons that Eric gives. To add one more: frequently there is a 'wall type' change as you go around the building. Snapping around manually allows you to switch wall construction as needed without having to go back and figure out where to break walls and modify them.

Erika wrote:
Often when I go into other offices, people have time and again commented about how just watching me,another person, work is beneficial.

I hear that as well. This is another reason that user groups can be such a valuable experience - even if the topic is something that the listener 'knows', the way in which something is done can often be an eye opener. 😉

Cheers,
Karl;