Why do I need a Drawing model?

In the MicroStation V8i (SelectSeries 1) release, you have a new model type called the Drawing model. Many of us are curious to know why this model type is added, what are its features, how is it different from other model types and so on? In this blog I will try to answer these questions.

Technically speaking, Drawing models are same as 2D Design models. Internally, there is an additional flag to designate them as Drawing models. If you open a Drawing model in MicroStation V8i or older versions, it shows up as a 2D Design model.

Logically speaking, the Drawing model is an intermediate stage between the 3D Design and the printable Sheet model. Though optional, you can use it in your Drawing Composition workflow to centralize annotations that need to be shared across multiple sheets.

To explain the use of Drawing models, let's take an example of the Design Composition project. You have it as an example project in the Building folder in MicroStation Workspace. In it, you have different floors. Each floor contains multiple rooms, a reception, conference rooms, etc. Now suppose you want to give labels and other annotations to each of these. To do this, the first option is to place the annotations in the 3D Design model itself. Something as seen in the following image: 



However, when you create sections of areas from the Design model, the annotations will rotate along with the models, get clipped along the sections and also clutter the design geometry. They would look something like: 

Hence placing annotations in a Design model is not recommended.

The second option is adding the labels in the Sheet models. You will place one floor plan saved view on a sheet to provide an overview of the entire layout of the floor. But then, the floor plan will also be broken down into multiple saved views of cubicles, conference rooms, etc. and placed on separate sheets. Now the question is how you will place room labels and other annotations. In this case you may have to place duplicates of each room label in every sheet.

The third option that I suggest as more suitable is using Drawing models. You create a Drawing model and attach the floor plan saved view coincident, at scale 1:1. Then you add the required room labels and other annotations associated with the floor plan. Now you create multiple saved views from this Drawing model - one for the entire floor plan, one for reception, one for conference room, and so on. Attach the floor plan saved view on a sheet. The annotations in the floor plan Drawing model are automatically rescaled to match the sheet's annotation scale. To add more annotations to individual rooms, create a new Drawing model for each room and attach the respective saved view coincident, at 1:1 scale. Attach rooms saved views in separate sheets as needed.


Some of the advantages of using this option are:

  • You need not consider the sheet scale while placing annotations on the Drawing model.
  • duplicating same annotations on multiple sheets can be avoided
  • You have the ability to pre-specify the detail scale of a Drawing model. When a Drawing model is attached to a sheet, the Drawing model's annotation scale is used as the attachment's default detail scale.

More blogs are coming up, so be there...