A cell is an element composed of group of child elements. Cells can be composed and placed from a cell library. Cell libraries are especially useful for repetitive placement. MicroStation provides various types of cells that can be used based on the requirements. Some of them are Graphic Cell, Point Cell, Shared Cell, Annotation Cell, etc.
In this blog, I will explain the usability of the Annotation Cells. Annotation cell is an element containing a group of child elements that can collectively behave as a single annotation, i.e. follow annotation scale rules. Like other annotations (text, dimension) it will be scaled according to the model annotation scale.
Why Annotation Cells
Instead of placing normal cells, if the cells are placed as an annotation cells, it gives flexibility to scale those cells anytime. Placing a cell as an annotation cell reduces our effort to scale multiple cells in the model at once, instead of selecting them one at a time and scaling it by Scale tool. Also there will be a consistent scale factor (only annotation scale) for all scalable elements (all types of annotations).
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Annotation Cell is a very handy tool which offers flexibility to CAD Administrators to customize their own annotations (symbols). These symbols are needed to annotate the drawing. Some of the examples of those symbols are room labels, door labels etc. Below image shows how various symbols (annotation cell) can be customized.
Creating Annotation Cell
You can define a model in the cell library to be placed as an annotation cell. You can do this in “Cell Properties” section of the Create Model or Model Properties dialog where “Can be placed as a cell” toggle turns the model to be placed as a cell and “Can be placed as an annotation cell” toggle turns the model to be placed as an “Annotation Cell”.
When the cell library is attached, annotation cells are distinguished by Annotation icon in Annotation column in the Cell library Dialog. Annotation scale will be applied to only those cells when placed.
Placing Annotation Cell
Once defined as an annotation cell in the cell library, you can place the cell with annotation scale lock “ON” so as to be scaled by model annotation scale.
Points to remember
While placing the cell there are some parameters that can control the cell size.
Annotation Scale– It is a special scale that applies only to annotations (like annotation cell)
Annotation Scale Lock – It controls whether to scale the cell with annotation scale or not.
Active Scale – It is the scale that is applied to every cell while cell placement.
Scale Annotation Toggle – If ON, annotations are scaled by active scale also. But recommended that annotation cell should be scaled only by annotation scale & not by active scale.
In upcoming blog, I will explain how existing normal cells (non annotation cells) from the old data can be converted to annotation cells & vice versa. Will also explain various methods of cell replace & effects of various parameters while replacing the cells. So be there.
The trouble with annotation cells is that they will almost always not be usable when scaled.
There is no intelligence to control the scaling point (origin of the cell). This is needed to ensure that the scaled cells do not clash with either the graphic elements or other cells.
The only case I can think of that would work if is the cell is used as part of a pattern. Is this on the horizon?
One idea is to place the annotation cells using a leader dimension. The cell would be scaled about the leader arrow point (which can also be associatively linked to a graphic element) in order to help preserve the offset from the graphic element.
Even this would not be fool proof, and some elements will still need to be moved manually. Maybe Mstn needs to allow the cell to be copied and hidden like with CVE items. Mstn would scale the cells as it loads the model, then compare the transforms of both versions of the cell, copy+transform the cell as a CVE item, matching the previous transform, delete the old cell, and hide the cell in the reference.