This Client Server article is republished in its entirety from 2003 for reference purposes.

By Robert DiMauro, Senior Technical Support Analyst, Model Engineering Products, Bentley Corporate Office
07 April 2003

Bentley Architecture and Bentley Structural v8.1 feature newly developed functionality that accommodates both 2D and 3D workflows by providing a single application and environment for designing and drawing in either mode. The key points of this new functionality are:

The same tools can now be used to work in either Plan or in Model mode. A designer can choose to work in 2D, in 3D, or both.
The plan can drive the model. A designer working in a 2D plan can, with no additional effort, simultaneously and automatically maintain a 3D model.
The new workflows let designers work the way they prefer, as 2D and 3D workflows permit dynamic collaboration on a project.
The same standards, libraries, and skills are used in 2D and 3D so there is no slowdown to implement Bentley Architecture.
The path to a 3D future is clean, fast, and optional for designers now focused on 2D.
Bentley Architecture and Bentley Structural v8.1 provide design professionals worldwide with a simple yet powerful 2D/3D Choice, so one application addresses your workflow needs.

The Four Design Modes

The user can choose the workflow or design mode that bests suits his or her needs, and can move between the modes as required. To start off in a given design mode, you simply start a new file, using the corresponding delivered seed file. Later, you can merge data from one mode to another by merging reference files (see your application's help file for more information).

Below are four unique and common design mode possibilities. The seed files mentioned are from the atf_us_ncs dataset, but similar seed files are found in each of the architectural datasets available. While Bentley Structural does not currently offer these same default seed files, you can easily create your own using the appropriate settings.

Design Mode 1

Drafting: atfplan_only.dgn
In this design mode, designers create in plan view only where there is no connection between a 2D plan and a 3D model. The focus is on traditional 2D drafting where a 2D plan drives the design process. It is intended for those who only want to work in 2D without ever seeing any 3D design.

Notice in Figure 1 that the View Group includes only a Plan model.

Figure 1: View Group with Plan Model Only
When placing walls in the plan model, they will automatically break or unify if they are intersected or joined together. In order for this to happen, the active Part definition must be set to unify in the Cut Plane and Forward/Reflected View Attributes of the Part Manager. This feature is also similar to the design workflow in PowerArchitect. If desired, a 3D designer could reference this 2D Plan model into an existing 3D Model. After it is merged into the file, the walls and elements will display in 3D so that the design process could continue in 3D. This is a function that far exceeds what traditional 2D drafting packages such as PowerArchitect could provide.

Design Mode 2

Plan to Model: atfplan_and_model_1way.dgn

This design mode will dynamically create a 3D model while you are placing elements in the 2D plan. Figures 2 and 3 show that there is a Plan and 3D Model in the View Group pick list. However, there is no 2D link between the 3D model and 2D plan. Designers who prefer to work in 2D, but who also would like to see what they are designing in 3D strictly as a reference would benefit from this mode.

The main focus of this mode is to isolate the 2D Plan from any work that is done in the 3D Model, being able to explore the 3D options at the same time as producing 2D plans. Elements that are exclusively placed in the 3D model will not affect any work that is done in the 2D plan since there is no section cut defined in the Drawing Extraction Manager and therefore nothing to calculate.

Figure 2: Plan Model in View Group

Figure 3: 3D Model in View Group
If an updated section is desired of the work that is done in the 3D model, a section can be created in the Drawing Extraction Manager that will produce a separate 2D model independent of the original plan model.

Design Mode 3

Plan and Model: atfplan_and_model_2way.dgn

This design mode has a two-way link between the 2D plan and the 3D model. The design file first opens to the plan model in which you can place elements, but you can easily switch to the 3D model by using the View Group pick list at the bottom of the screen. The main difference between modes 2 and 3 is that in Design Mode 3 there is a Plan Section definition already set up in the Drawing Extraction Manager, in which you can also calculate the work done in the 3D Model to be displayed in the 2D Plan. Any work done in the 2D Plan model is automatically displayed in the 3D Model, just like in Design Mode 2. Notice in Figure 4 that the "Update Master Model" option is turned on in the Output tab of the Drawing Extraction Manager.

Figure 4: Drawing Extraction Manager - Update Master Model Option On

Figure 5: Cut Plane Location
If on, a link is created from the 2D plan model to the 3D master model and that will propagate all of your changes. If it is turned off, you will create a plan with no link back to the 3D, similar to Design Mode 4. By default, (shown in Figure 5), the cut plane location is taken at four feet above the global origin coordinate point - a standard in the U.S. This can easily be changed if desired by redefining the section cut in the Region tab.

Design Mode 4

3D Modeling: atfmodelseed.dgn

In this design mode, designers can work in the 3D model and extract 2D drawings from the model. Here the focus is on the 3D model and data extraction. In this case there is a one way dynamic link which permits editing of the 2D drawings generated from the 3D model, but prohibits the 3D model from being edited using the 2D drawings. This is the traditional TriForma drawing extraction setup. Notice in Figure 6 that the "Update Master Model" option is not activated when using this seed file so that it does not allow for the link from the 2D plan back to the 3D model. All updates to the 2D plan are done from the Calculate All button in the Drawing Extraction Manager in the 3D model.

Figure 6: Drawing Extraction Manager - Update Master Model Option Off Summary

This article is simply meant to summarize the 2D/3D Choice to help a designer make the decision as to which design mode suits his needs best. For an in-depth look at the options in Bentley Architecture, as well as .avi movie links, see "The 2D/3D Choice" in "What's New in Bentley Architecture V8.1" and "QuickStart Guide" sections of the Bentley Architecture Help.

Bentley Structural summarizes "The 2D/3D Choice" in "What's New in Bentley Structural V8.1," found in the Bentley Structural Help file.

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