TBC File Size Question

This kind of question comes up fairly often - I have posted on it before I am sure but here was a response I sent a user this morning. They said that their file size had bloated up to 340MB and they could not understand why that was.

Couple of things first - TBC stores VCE files as Binary Files but they are stored in an uncompressed state - this means that they are larger on the disk than maybe some other software products that compress the files on disk but expand them into memory on opening - this makes it look like their file sizes are smaller but in reality they are not typically smaller for the same exact data. Also TBC holds most of the data in the project file, however items like Point Clouds and Image / PDF pages are referenced from a folder location into the project file because they are tiled for faster display at different zoom levels - so if you look at a PDF page saved out from Bluebeam and then look at the file size of the same page in a TBC folder it is larger because it is now an Image that is tiled at different resolutions to make it clearer at different zoom levels.

It is also easy to lose sight of all of the data in the project - remember TBC has Plan, Profile, Section and Sheet Views. Sheet Views of imported Section data (in this case there were ~150 pages of sections in the sheet view that provided over 190000 CAD objects that equated to 200MB of the 3900MB file.

Here is the summary detail of what we found in the file.

The VCE file size is 342729 KB (342MB)

If I back out the data bit by bit from the file, this is how the file size reduces

  1. All of the Section Data in the Sheet View -there are 181958 CAD Objects made up of 16229 Multiline Text Objects, 157896 CAD Polylines and 7833 Linestrings. If I delete all of those the file size reduces to 98160 KB (98 MB) so these account for 244000 KB or 244MB. This is an average of 1.3kb per cad object

  2. Plan View Data Objects were 7924 (26 Boundaries, 644 CAD Lines, 338 CAD Text, 1 Alignment and 6915 Linestrings. These reduced the file size by 381 KB an average of 20.7KB per object

  3. Feature Code Library - Reduced the file size by 7 KB

  4. ANSI B Planset Removal - Reduced File Size by 88.33 KB

  5. Placeholder Surfaces for Takeoff (FG and EX Surfaces that are empty) - Reduced File Size by 2KB

  6. Removal of PDF Section Sheets from Imported Files - this seemed to increase the file size - not sure why - it was a small change however

  7. Removal of Georeferenced Plan Sheets - This was the second biggest jump and was 97.7MB - I am not sure why that is so large because all of the image data is stored externally and is referenced into the project but it was a big chunk - there were 26 pages each being ~3.7MB

  8. The other imported files in the imported files list accounted for very little and the residual template with everything removed is 72KB

If I start a new project with the Template that we provide that starts at 633KB total.

So to summarize - the things that took up all the file size were the 190000 CAD Objects in Sheet View and the PDF Plan Sheets

I don’t think a couple of KB per CAD object is large so I am not seeing the file size as being Excessive.

I saved the file out as a DXF File, loaded into AutoCAD and saved it as a new DXF and the file size was and this excludes all the Georeferenced Sheets etc., the Feature Code Library - I used a DXF because an ASCII DXF is uncompressed like a VCE file and that is the only direct comparison - a DWG file is saved compressed but expands into memory when opened so it is not a good direct comparison. The DXF file size that TBC writes out is 1.92GB so 4x larger than TBC VCE file for less of the data

A DWG written from TBC was and this is a binary compressed file - 416358MB and is still larger than TBC file - I opened it in AutoCAD and then saved it as a new DWG and it became 453MB so larger than the file that TBC wrote with no changes to the file

Not saying that AutoCAD is a great example but it is an alternative that is used in the industry …