Wishes
Post your wishes about Graphisoft products: Archicad, BIMx, BIMcloud, and DDScad.

Skew tool

Paul King
Advisor
I frequently need to be able to de-skew scanned floor plan images that I am attempting to trace - so would appreciate it if image handles could be pulled independently of one another, distorting (correcting) the image accordingly.

This is not something that can as easily be done in a separate package - you need the known CAD information overlaid and snappable in order to accurately determine the extent of de-skewing required.
PAUL KING | https://www.prime.net.nz
ArchiCAD 8-27 | Twinmotion 2023
Windoze 11 PC | Intel Core i9 10900K | Nvidia Gforce RTX 3080 | 32 Gb DDR3 | 2x4K monitor extended desktop
17 REPLIES 17
Anonymous
Not applicable
This would be handy on occasion but I must say I haven't run into the need in quite e few years.

It was more common when lots of drawings were physically scanned by machines that didn't track so well. With 99.99% percent of my reference docs coming from computer files (nearly all PDFs) this isn't really a problem for me any more.
Paul King
Advisor
Sadly, a lot of my work is remodels to old buildings - so scanned drawings (or scanned microfiche) is the best I will get - so skew tool would be rather handy. Would be useful for other elements as well - slabs, walls etc
PAUL KING | https://www.prime.net.nz
ArchiCAD 8-27 | Twinmotion 2023
Windoze 11 PC | Intel Core i9 10900K | Nvidia Gforce RTX 3080 | 32 Gb DDR3 | 2x4K monitor extended desktop
Dwight
Newcomer
Photoshop has a measurement and scale tool in the latest release.
Dwight Atkinson
Paul King
Advisor
Not sure how useful that would be to people who need the snappable CAD model overlaid with scanned data in order to de-skew scanned data ...

Tracing over scanned data is an integral part of day to day ArchiCAD work flow for poor suckers like myself, so should not need to be extra steps & software - seems such a simple thing to add to existing handle functionality!
PAUL KING | https://www.prime.net.nz
ArchiCAD 8-27 | Twinmotion 2023
Windoze 11 PC | Intel Core i9 10900K | Nvidia Gforce RTX 3080 | 32 Gb DDR3 | 2x4K monitor extended desktop
Ralph Wessel
Mentor
Paul wrote:
Not sure how useful that would be to people who need the snappable CAD model overlaid with scanned data in order to de-skew scanned data ...
Have you tried importing the CAD model (exported as an image) into Photoshop and layering it under the image for de-skewing?
Ralph Wessel BArch
Paul King
Advisor
Hi - thanks - yes certainly been there done that sort of thing, for lack of any decent alternative , but never very satisfactory - it involves extra steps, and extra software & is not very quick or much fun to do given the huge size of tiff images produced in scans - and so you need comparably large & detailed versions of CAD plans to overlay - and attempting to align two huge bitmaps , rather than just one bitmap over a vector based CAD file adds extra inaccuracy...
Definitely not a great workaround in my experience - especially when a job can have dozens of scanned plans that need to be de skewed & accessible... and seems doubly crazy when you already have open the very application the image is destined for!
PAUL KING | https://www.prime.net.nz
ArchiCAD 8-27 | Twinmotion 2023
Windoze 11 PC | Intel Core i9 10900K | Nvidia Gforce RTX 3080 | 32 Gb DDR3 | 2x4K monitor extended desktop
Anonymous
Not applicable
Paul wrote:
...seems such a simple thing to add to existing handle functionality!
ArchiCAD is not a bitmap/image editing program (though it is quite impressive in its handling of image files compared to the competition) so I suspect that de-skewing functions would not be trivial to implement. Scaling bitmaps is basic stuff. Skewing is another matter.

I suppose that if just a simple angle skew would work that might not be a big deal (InDesign has it), but in my experience with such things the scans often need the more detailed attention that only Photoshop can provide.

I guess it comes down to how many ArchiCAD users need this. If there are enough then it could be worth GS' time to implement, otherwise it amounts to special conditions in your practice for which you need special tools (ie Photoshop).
Hi,

Unfortunately there are places in the world...where some surveyours still provide their work as hand drawn plain piece of paper ;(
and because of that some controll over the bitmaps would be welcome..
ie deskewing, greying-out etc.

Best Regards,
Piotr
Paul King
Advisor
Matthew wrote:
I suspect that de-skewing functions would not be trivial to implement. Scaling bitmaps is basic stuff. Skewing is another matter.
I think ArchiCAD has all the bitmap handling functionality it needs in place already - when you skew, you are just rescaling along one axis, but with scale factor that is proportional to distance from origin along other axis - basically just need an extra couple of variables in the existing rescaling function.
PAUL KING | https://www.prime.net.nz
ArchiCAD 8-27 | Twinmotion 2023
Windoze 11 PC | Intel Core i9 10900K | Nvidia Gforce RTX 3080 | 32 Gb DDR3 | 2x4K monitor extended desktop