Calculating the area of multiple elements containing interior shapes

Hi,

similarly to Jon, I'd like to ask (not only) about the version you use, but also the product. Both information are important, because define what tools are available.

RoosaK said:

I have a map

Map data is generally better processed in Bentley Map / OpenCities Map products, because they are optimized for GIS and geographical projects.

RoosaK said:

Majority of these areas contain a smaller area inside them.

How the areas (and the whole map) is created and in what structure? Is it boundary topology, or areas in different layers are shapes or complex shapes (so a border of adjacent areas is duplicated and overlaps)?

RoosaK said:

I would like to calculate the area of all certain layer elements

Possible solutions and whether it can be done in plain MicroStation depends on data structure (closed elements vs boundaries created by linear elements).

Regards,

  Jan

I am using Microstation Connect Edition version 10.16.00.80.

The map that I am dealing with is created basically just by drawing different size and shape polygons that represent the borders of the area. Different kind of areas are on different levels (area1, area2, area3 etc.) So basically I may have a very large area on level 1 and inside that there may be several other smaller areas on many other levels.  If these smaller areas have a common border with another area the borders overlap each other at the connection. The smaller areas can also be just totally separate areas inside a bigger one with no connection to other area boundaries. Does this make sense or am I being too unclear? 

RoosaK said:

Does this make sense or am I being too unclear? 

Well ... a picture would make it a bit clearer.

RoosaK said:

I am using Microstation Connect Edition version 10.16.00.80.

That's good. In such case, as mentioned by Jon Summers, you can create reports. In the simplest case, every report can filter shapes from one level and to sum their areas. To keep it simple, to subtract one level from another has to be done manually.

It works as long as subtracted area is bigger (it covers) then the second area.

Or, you can simply select all shapes at one level (can be done simply using Element selection tool) and to use Measure area tool. It automatically sums all selected areas.

The approach, mentioned by Oto is also good and is close how it is done in GIS systems: To create temporary objects, representing topology operation. In this case it should also be simple: Select both layers (areas and "holes") and use Group Hole tool. It topologically merges all shapes and maintains holes, so area of the result is "total area - area of holes".

Regards,

  Jan

Here's a screenshot of a small area. Should have put a screenshot with the question in the very beginning.. The red arrow shows an example of an area inside a bigger one. So if i measure the bigger area it counts in also the smaller one inside. Except if I use the flood option and locate interior shapes it works fine for one area but I couldn't get it to work when multiple areas are chosen. 

RoosaK said:

but I couldn't get it to work when multiple areas are chosen.

Did you try some from the discussed options?

Both reports (when all areas should be calculated) and Oto's grouped hole (for selected elements) should work fine.

Regards,

  Jan

I would approach the task like this:

1. Create a new design model
2. Reference the mapping model into the new model
3. Use the region tool to flood fill each of the areas to be counted in the measurement
4. Turn off the display of the mapping file
5. Select all
6. Activate Measure Area

Quick and easy

Can you upload the DGN file?

RoosaK said:

Different kind of areas are on different levels (area1, area2, area3 etc.)

RoosaK said:

I am using Microstation Connect Edition version 10.16.00.80

Then use my suggestion to create an Area Report...

• Include the level name in the report
• Save the report as an Excel file
• Compute net area in Excel, filtering by level name (e.g. net area = sum(area1) - sum(area2))

Jan Šlegr said:

Map data is generally better processed in Bentley Map / OpenCities Map products, because they are optimized for GIS and geographical projects

If you're going to do a lot of this, then invest in a GIS tool.  GIS products such as those mentioned by Jan are designed to help with the area takeoff that you need.

Lorys said:

Jon Summers also has AreaAnnotator to label all the shapes then you can search for the islands and  get the difference .. but unless all you shapes have some unique ids its not really much use for reporting

Thanks for the citation. AreaAnnotator would help, particularly if the OP want to assign a label to each shape.  In the context of this thread, consider AreaAnnotator as an entry-level low-cost GIS tool.

RoosaK said:

Different kind of areas are on different levels (area1, area2, area3 etc.)

RoosaK said:

I am using Microstation Connect Edition version 10.16.00.80

Then use my suggestion to create an Area Report...

• Include the level name in the report
• Save the report as an Excel file
• Compute net area in Excel, filtering by level name (e.g. net area = sum(area1) - sum(area2))

Jan Šlegr said:

Map data is generally better processed in Bentley Map / OpenCities Map products, because they are optimized for GIS and geographical projects

If you're going to do a lot of this, then invest in a GIS tool.  GIS products such as those mentioned by Jan are designed to help with the area takeoff that you need.

Lorys said:

Jon Summers also has AreaAnnotator to label all the shapes then you can search for the islands and  get the difference .. but unless all you shapes have some unique ids its not really much use for reporting

Thanks for the citation. AreaAnnotator would help, particularly if the OP want to assign a label to each shape.  In the context of this thread, consider AreaAnnotator as an entry-level low-cost GIS tool.