It would be helpful if parametric cells could contain lines on different levels which stay after placing the parametric cell.
The behaviour I am looking for would be the same as with "normal" cells. Everything that is on a specific layer in the cell library gets placed on that layer in the file where you place the parametric cell.
Case Scenario:
Creating many different drawings of vessels or similar equipment with a bunch of standard parts attached to theses vessels.
We want to create a parametric cell library where all of our standard parts will be included in the future. For example that would be flanges.
In our drawings we use different layers to differentiate the different line styles like dashed, point-dashed and so on. For example all our centerlines lay on the "centerline layer" and have colour, line weight and line style set to "by layer". If we create the parametric drawing of a flange with the lines set to "by layer" and then place the parametric cell in a new file, all lines are put on the same layer and we cannot differentiate anymore between main lines, center lines, hidden lines, etc.
Here are two pictures, where I changed one of the red centerlines to "by layer" and that one is not dashed anymore after placing the cell on the right picture.
(Note: I did it only for one line, to showcase the example. The workaround we do at the moment is to set the lines manually to their "style values" like red color, dashed and so on. So it does not matter on which layer they are after placing because the look of the line is "hardcoded" in the cell)
One could ask:
Why do you want your lines on seperate layers if you can just change the look of the line in the cell library, independent from the layer it lays on.
Answer to that:
We use the different layers to be able to change the look of, for example, all the centerlines by just a few clicks, without having to grab every centerline one by one. We have cases where the customer wants the lines to look differently than our standard and if we have them laying on the layer and set everything to "by layer" we just have to change the style of the layer in a few clicks and everything gets changed accordingly.
One could also ask:
Why do you want to use a parametric cell library for that and not just a normal cell library?
Answer to that:
Actually we were doing it for a long time. But it is really annoying to draw each size of a standard part one by one. Most of the parts follow a kind of design intend with different parameters. So we would like to take advantage of parametric modelling to get more efficient. In addition to that: If anything changes in a part, for example we do not want to show a specific line anymore we could delete it one time and do not have to do that operation for all the drawings of the same part, which are just a different size.
Another reason is:
If we would use a normal cell library the list of standard parts would get really, really long. For flanges only it would be several sorts of flanges, all coming in several sizes, then in different norms and so on. So the list to include all the flanges we need would be long for itself. Now if we want other standard parts in the same library, for example elbows, t pieces, different forms of vessel-heads and so on the list would get longer and longer and one would have to scroll endlessly to get to the right component.
This is a similar request to MSR-I-656. Bentley should note and heavily consider that multiple people are asking for this functionality.
Thanks to you for your feedback Ivan, it is very important to us as it is was drives our efforts. Our goal is to make our parametric cell a good balance between ease of use, flexibility and of course robustness. I hope we will be able to offer some incremental updates that will keep you and our users use parametric cells and help us take them to the next level (or two :) )
Whatever respects workflows which are eligible for perproject changes to "baseline" libraries is very welcome :)
As a customer i hope you will come up with a robust future proof solution to comprehensive cell managment and use, not just a minor improvement. I feel cells are bit lacking right now. Thanks for this discussion.
Thanks Ivan. When you start changing a lot of properties from the original cell definition model, being for a project or a single file, it can become then complicated to manage cells, performs, updates, etc. I can envision a way where, after placement, you could modify a cell in-place (its symbology or more) and then either update all the existing instances in that file or promote the modified cell to a new definition and maybe push it to a library for re-use.
This way you could have a "baseline" library of cells that you could quickly modify in context and make part of a new project-based library without having to plan for all possible requirements when creating you baseline libraries.
I can imagine full uncompromised functionality which would be likes this:
-you can change levels of subobjects after placement, either directly change level to "levelXY" or to "by Parent" (inspiration from different cad), in case of subobject parent would be the level of the cell, in case of nested cell, level of a nested cell would be derived from parents cell level
-basic properties woul be optional "according to direct parameter", according to "by level" "by parent" with same logic as explained above
-in practice there could be a huge global property to cells "get attributes from cell or individual adjustment true/false" or even add an option to "by level" "by parent" another "by library definition" or something which would ensure all the properties are as defined in the library.
Reasons behind my words:
It is impossible to maintain libraries of objects when you have to know in advance what levels you want your objets to lay on and what kind of properties you want to have eventually (or which item types you will use thats why i advocate for WF when you attach item types in the model not in the libraries). There are different standards on different projects. Structure of cells (geometry mainly, variables, and how it is put together) usually always remain the same whilst properties and attributes change.
These are reasons why it is essential to be able to change all this after placement. If not possible the future of collaboration will be even bigger nightmare when organizational old fashioned non-changing libraries wont be applicable due to different BIM standards in every country and on each project and still larger globalized collaborations.
No, unfortunately you can't change the symbology of individual elements inside a parametric cell after placement. You can change the symbology of the level these elements are on but not the symbology of an element directly, for a single instance. We are working at adding an additional workflow, where elements in a cell that are on the "Default" level and have symbology set to "ByLevel" will pick up the symbology of the level the cell is placed on.
To Marco Salino. But you cannot change level of a cells subobject after placement. Or?
MicroStation CONNECT Edition Update 15 added support for bylevel symbology of parametric cells.