Asymmetric Scaling of PDFs'

[Donald Wardlaw]

When importing a scan of an old blueprint, the blueprint is normally not accurate scale wise in the 'x' direction---because the drawing stretched in the long paper direction as it went through the roller of the blueprint machine.

 

If I try to use this as an underlay to accurately create a new base drawing in vector form, I need to scale the 'x' and 'y' coordinates of the pdf differently.  What I'm finding is that "Scale Objects" allows the entry of different values, but will not scale them to different values.  This is VW2017.

 

I can work around this but it takes a lot more time.

[AlanW]

Hi, you can scale asymmetrically by factors and will scale a pdf by different values.

HTH

[Donald Wardlaw]

Alan,

 

What I find is that, yes I can enter the different factors, but the scaling will not happen.  I can create two rectangles, same size, and apply the two factors to one of them, and it scales asymmetrically.  But, the pdf will not.

[markdd]

I have experienced this too. Not sure if asymmetric scaling of pdfs is supported despite VW allowing you to try. Why not submit it as bug?

 

Mark

[AlanW]

Hi,

See attached, seems to work.

[PVA - Admin]

I am able to use the Asymmetric scaling mode of Scale Object on PDF pages here on 2017 SP2 running on macOS 10.12.2.

 

Asymmetric scaling SHOULD be possible with PDFs as far as I am away, both via Scale Objects as well as the reshape handles. Could you try it with the attached PDF, which worked for me, in a new blank document on your machine in 2017 SP2 please @Donald Wardlaw?

 

 

Philenor_Floorplan.pdf

[Donald Wardlaw]

Jim,

 

I can scale your pdf, in the file I was working with 2017 current, but El Cap, also current.

 

That makes it look like the problem may lie with the pdf.  Here are the particulars in a "grab" screen shot.

pdf data.tif

[PVA - Admin]

If you can, send me that original PDF in a direct message and I can have a look and submit it for engineer to take a look at to see why it would behave differently. I don't recognize the "Encoding Software" source so that would be my first guess on a culprit, but honestly I do not check the info on PDFs very often other than filesize.

[Donald Wardlaw]

Jim,

 

I sent you a VW file with two versions of the same pdf in it.  You can asymmetrically scale the larger one but not the smaller one.  The smaller one had been scaled uniformly two or three times.  It appears that something happened to the pdf that was in my file.  It looks like there is not a general scaling problem.

 

Thanks to all,

 

Donald

[MullinRJ]

Donald,

One caveat to scaling PDF's, the rotation of the PDF must be a multiple of 90° from its original orientation after it was imported into VW or it cannot be scaled asymmetrically. You have to scale first then rotate. If your scan is crooked on the PDF, such that the axes you want to scale are not perpendicular to the PDF page, you will have to rescan the blueprint and try to control its orientation through the scanning process. 

 

As you may have noted, you can scale a PDF symmetrically, even after it was rotated and/or scaled asymmetrically.

 

On your problem PDF, try placing a new copy in your drawing, scale it (asymmetrically), then rotate it as needed. If asymmetric scaling still doesn't work, there may be something wrong inside the PDF.
 

HTH,

Raymond

 

PS - The same scaling caveat applies to Bitmapped Images. Place them, scale them, rotate them.

[Donald Wardlaw]

Raymond,

 

I think you nailed it.  Good insight.  I did in fact rotate it slightly, say .4 degrees to correct for misalignment in the scan.

 

It makes it a bit tricky since it is not too hard to figure out the scale factor in the x,y coordinates of the drawing, but that would not be the same factors for the x,y of the drawing file.

 

Doesn't VW allow for turning the ground plane for working with floor plans that have a wing that is at an angle?  I wonder how scale objects works in that case and whether I could rotate the ground plane, make true asymmetric scaling, return to normal ground plane orientation, then rotate the pdf?

 

Off to the lab....

 

Donald

[Donald Wardlaw]

Close but...

 

If I rotate the plan to put the pdf in a squared up alignment, it behaves like rotating the pdf without rotating the plan.

 

Other objects, say a rectangle, will scale correctly, asymmetrically in a rotated plan.

 

d.