Question

dgn to dwg conversion

8 years ago
13 August 2015
5 replies
58 views

tlabs
25 replies

My current employer is converting from using Microstation to AutoCAD and I was wondering if anybody can give me some advice. I'm looking at many DGN files to convert to DWG and i'm concerned all the cell's in Microstation will get dropped in the process. I'm not sure how the conversion process will convert the cells data into blocks?

Are their certain library's in AutoCAD that need to be prebuilt?

Any assistance would be greatly appreciated.

5 replies

pratap
Participant
594 replies
8 years ago
14 August 2015

Hi,

Blocks have to be defined in dwg template as well as mapping of attributes need to be reviewed (i.e. level name = layer name).

Pratap

tlabs
Author
25 replies
8 years ago
14 August 2015

Pretap, what do you mean by the Blocks being defined in a dwg template? Do I need to re-draw all of the Cells I have in Microstation in a dwg?

pratap
Participant
594 replies
8 years ago
17 August 2015

If you want to use the cells as blocks then you have define the blocks. No need to redraw them at every instance.

Hi @tlabs

as @pratap mentioned, ideally you need to have a template file with all your block definitions. To create a template, you can

read your source dgn-file(s) with Expand Named Cells checked to expand cells into elements and Preserve Named Cell Insert Points unchecked to avoid reading cell insert points as features;
filter one instance of each cell (using igds_cell_name and igds_cell_insertion_x/y/z attribute values);
aggregate all elements belonging to the same cell (using igds_cell_name as Group By attribute);
name the aggregate (future block) by adding autocad_block_name attribute and setting its value to igds_cell_name;
write the named aggregates into template dwg-file.

When you will be processing your source data, please uncheck Expand Named Cells in Bentley MicroStation Design Parameters (Reader parameters) dialog to read cells as points and use your template dwg-file for writing (see Writer parameters).

Please take a look at https://knowledge.safe.com/questions/25231/cells-to-blocks.html where @DaveAtSafe explains a more advanced block definition scenario.