Vertical axis not aligned when using Match Photo

matchphoto

#1

I am using a photo of a house, taken from the corner and out far enough to get all of the building. The photo is taken using iPhone 6. I imported this into Sketchup without any processing/cropping/rotating/etc. When I accurately align my red and green guides (by zooming in on each endpoint and carefully placing them along hard straight lines, my horizon establishes itself fairly accurately, but when I go to place my axis origin, the vertical is noticeably off of vertical with respect to the line of the house. My desire was to use the closest corner as my origin, but it is the corner that least matches the blue axis with the vertical of the building. The other two sides (left and right) are closer, but still off. So, the obvious effect is when I start at my origin to draw my first vertical line to begin mapping geometry to the photo, it’s wrong. I also correctly scaled the grid to actual building measurements.

I have watched the Sketchup Training Series YouTube vids and read the Sketchup Help Center (Matching a photo to a model) material, but in all of these examples, the axis seems to align itself perfectly to the vertical in the photo used after correctly placing the red and green guides.

I can’t seem to find any similar complaints. Any advice? Thanks!

SU Pro 2017, Mac OS X Sierra 10.12.1

-njw


#2

Share the file so others may be able to help.


#3

I would suspect the camera in your iPhone is distorting the image. Have you been able to successfully use other images taken from your phone’s camera for Match Photo? On my phone there is a noticeable distortion. When the phone is held horizontally, there is a distinct vertical compression of the image. It makes people’s faces look fatter and building a bit shorter and wider than they are.

Sharing the SKP file with us would make it easy to ensure there isn’t something you’re missing in your set up.


#4

Thanks for response, guys. This is my first go at using Match Photo, so I have no other experience to draw from. Attaching file. You will notice the divergence of the vertical axis from the edge of the building by a more than nominal amount. Thanks. :slight_smile:MatchPhotoVerticalAxisMismatch.skp (2.5 MB)


#5

After looking at your file, I think you should reshoot the image with that corner of the house centered in the image.

It really isn’t off by very much but it’ll probably be better if you get the house centered in the image.


#6

Cheers, DaveR. I will try again, as well as try shooting portrait, rather than landscape- as you mentioned could also be a culprit. It is interesting to learn that there doesn’t appear to be a known issue with this, and therefore known tips… that it rests with me and likely my inputs. I will keep trying . Thanks again for your feedback. :slight_smile:


#7

Good luck with it. How about reporting your results?

I think it would also be useful to take the photo with a regular digital camera framed up like you did for the image in this file. See if you get the same result.


#8

Why not just rotate the photo in an image editor to get the near corner of the house vertical?


#9

I actually tried that, but when you rotate it, you also end up cropping it slightly. But I tried it anyway, and rather than helping it actually aggravated the problem.


#10

Sorry, posting from my phone so I haven’t been able to look at your model. Re-shooting seems the way to go, then.


#11

Thanks to everyone for comments and feedback. I took multiple repeat images using normal DSLR, being sure to exactly center the corner in the frame, etc… I tried portrait and landscape and always ended up with the same skewed vertical axis. As it turns out… being an 85 year old Norwegian timber farm house, the house really is that far off of plumb. :confused: I took a level to the wall and it’s skewed the same direction as SU indicated and by about the same amt.

Just my luck that the first time I try tusing match photo, I use a wonky house. I guess I will just try to live with slight bust between perfect model (90 deg angles) and imperfect reality.

Thanks again, guys. Sorry to waste your time on this one. :slight_smile:


#12

Funny. I wouldn’t have thought it would be off enough to cause a problem. Well, at least it wasn’t really you and you figured it out.

@john_mcclenahan, Match Photo doesn’t work if the image has been cropped or otherwise manipulated in an image editor. It wants an untouched image.


#13

Sorry, I didn’t know that - out of curiosity, how can SU tell if image has been edited?


#14

It can’t really “tell” be cropping (which would happen if you convert an image such as the OP’s from horizontal to vertical) changes the center of the image.