Item Types and Constraints

Question

Is it possible to use a length property in an item type to control a dimension in a graphic cell? What if the cell has multiple instances in a Model? I am working on a library of traffic signal cells and am trying to use one mast arm cell to cover all the necessary lengths (Say 20 ft to 70 ft). I can change the length of the mast arm through a constraint but i also need to change it in the item type data. If this linkage is possible, i would be great to see a video tutorial on it. The images showing the constrain and the item type are from the same element. 
 Thanks, 
 Jason

shunnai.zhao · Answer

I suppose that most of MicroStation users meet the same question when using item type properties as variables. some key points will help you understand the right process. 
 1. the purpose of using item type properties as variables is to create a parametric cell attached with item type definition. the item type properties can drive cell's dimension. whatever you work in a *.dgn or *.cel file, the key point is to set the model as a parametric cell in model's property dialog. 
 
 2. Don't need to attach item type to object in the model that will be placed as parametric cell later . when you select item type as variable, you have attached the item type definition to the model(remember that it is attached to a model, not to objects in the model). that's is the reason that you can only select one item type when you use its property as variables. that is also the reason why you can only choose one item type definition in a model. 
 
 3. The reason why you can't find the item type property variables is that you don't set the item type property definition correctly. you must set the "units" with "distance". otherwise, it couldn't be identified.

the above three key points are enough to let you use it successfully. Enjoy~~

Item Types and Constraints

Top Replies