View Groups in MicroStation...

               This blog explains the concept of "View Group" in MicroStation. View Group is actually a set of eight view window layouts. In other words, it's a set of eight views. You have been using view windows for looking at the 3D model with different orientations, angles and sizes. Actually it's a view group that lets us do that.

               To explain it usability, let's take an example of the case when you are working on a 3D model. This might be a big building, stadium layout etc. This again might consist of several small details like piping, corner, door etc. You might be visiting these small detailing with zoom out/in. You may also want to see the top, front and isometric views all together. You have the liberty of using these 8 view windows to look at the same model with different orientations. Moreover you have the option to save those into dgn file in case you don't complete the work in one session of MicroStation.

               Additionally this also helps to access and navigate through different models. View Group tool keeps track of our models visit sequence and thus helps in going back and forth to different models.

               The above dialog is actually "Manage View Groups" dialog. This actually shows the list of view groups in the active dgn file. Normally you have as many view groups as models. When we create a model, we have an option of creating a view group for the new model (Notice the "Create View Group" toggle at the bottom of create model dialog). We name the view group same as the model name although we have the liberty to rename it and change its description using above dialog. You may choose not to create a view group for a model. In this case, the view windows that you see are temporary views. We generally indicate this temporary view group by adding "Temp Views" suffix with the model name. You can see "Untitled Sheet Temp Views" in the above picture. This does not get the saved to dgn file. Every time you open this model, the temporary view group gets created to display the contents of the model.

               When you create a view group, by default, the active view group is used as the seed view group. However, another view group can be designated by setting the configuration variables MS_VIEWGROUPSEEDNAME or MS_VIEWGROUPSEED. MS_VIEWGROUPSEEDNAME allows you to set the name of the view group in the current file to use as a template. MS_VIEW GROUPSEED allows you to set the name of the file where the template view group is located.

               Model and View Group are two different entities. Model is just a container which knows about all the elements. A model can be associated with a single or multiple view groups. It's a view group's responsibility to display the contents of the model. Since a view group contains a set of eight views, each view can correspond to a different model. A view group has the capability to display the contents of eight different models. If we associate a view group with more than one model, MicroStation names it as "Multi-Model Views". Again you can rename it if you want and save it in the dgn file using "File->Save Settings". You can see the multi-model views in the above picture.

               Then the question is how we can see multi-models in a view group. You can do this using "View Attributes dialog". This dialog shows the settings for one particular view. If you see the view setup section of this dialog, you will see the model associated with this view and also the option to switch to a different model. Likewise you can choose different models for each view window. The model name for each view shows up in the view window title bar.

               When you create a view group while creating a model, all the views correspond to the same model and this gets saved to dgn file. The multi-model view group does not get saved to a dgn file until you do save settings. Every time you invoke more than one model for a view group, the same view group with name "Multi-Model" gets active and all changes are saved into this view group. If you want to have more than one multi-model view groups, you need to give them unique name, a name different from the default name "Multi-Model".

               This is actually view group toolbox. As you can see, it keeps the history of view groups that you have visited. It also keeps the history for inter-file view groups visits. The back/forth arrow takes you to the last visited view group.

More blogs coming up, so be there...