Match photo using 4 or more photos


#1

I originally posted this to the wrong forum. My apologies…

I have a simple (10’ x 12’ shed roof) woodshed that I would like to photo match in order to build off it a car port.

I cannot imagine a good photo match of a rectangular structure involving less than four pictures. I took four pictures—clockwise—each from a successive corner of the shed. None of the photos were cropped.

Photo #1: I’ve done quite well in doing a photo match to photo #1 (no brainer). Positioned the axes origin (yellow square) as recommended in most photo match videos. Scaled to a spacing of two feet (all the measurements were great). Then drew and pulled a 3D model that accurately represented the shed.

Photo #2: Importing photo #2 went well, and realigning the axis required minimal work. I left the axes origin where I’d positioned it in photo #1. The model needed to be resized (click/move on an axis) in order to fit the photo, but it was a nice fit. [Going back to photo #1 confirmed that the model fit well.]

Photo #3: The import was straightforward; as was (very slightly) repositioning the (red, green) parallel axis lines. (To make the job easier I’d chalked marks around the shed). The axes origin (yellow square was positioned somewhere within the shed (indicating that it related to the bottom corner of the shed on the back corner (blind corner) of the shed. This time the shed model was the right shape (and the corner/sides pretty much lined up) but high (started above the bottom of the picture and extended that amount over the roof of the picture). All attempts to resize the model resulted in a model much too small to relate to the picture.

I doubt importing photo #4 is going to help, and can’t figure out what to do now. Something tells me that if there were the ability to (congruently) resize the photo I would be able to get the model to fit.

Photo #4: Nonetheless, I imported photo #4, made sure the axes origin was where it was located in photo #1); and realigned the red/green lines. The model was again the correct shape, but not the correct size.

Again, I think the problem could be solved by being able to resize photo#4 but SketchUp doesn’t seem to provide that capability. (The forum popup says Your topic is similar to “Add photo texture” Would this match photo question relate in any way to adding photos as textures???)

What do you recommend I do?
Also, are there any SketchUp videos or tutorials that cover importing more than two photos of the same structure, and dealing with model resize problems particular to those photos?

Thanks


#2

Workshop model_d.skp (2.4 MB) This is an extremely simple example of what I assume is a more general problem. For that reason I’m attaching the file.

Note that:

  • (tab) Woodshed_a_001#2 is Photo #1. Everything is initially aligned to it.
  • Woodshed_a_002 is Photo #2 (it would be nice to move the tab position). It required the model resize.
  • Woodshed_a_003 is Photo #3. As you can see, the model is quite off from the photo. I don’t know how to remedy this situation.
  • Woodshed_a_004 is Photo #4.

#3

When you mention realigning the axis… do you mean that you dragged the yellow axes square while in MP edit mode or do you mean repositioning the axis before performing the Matched Photo import?

I modeled an entire downtown using a stitch method, but the requirement is that I always had a corner in common between two imported images. Maybe this is what you did, but in general I:

  • Import image, perform MP.
  • Rotate model to roughly match up with next image that I am about to import.
  • Use the Axes tool to set a new axes.
  • Import image 2, do MP as before.

As long as the same “corner” can be seen in both photos, this process seems to work. I noticed on the 003 scene, your “match photo” yellow-square axes is behind the part you can see in the image. I generally always want that to be on a known location in the image.

THAT being said, I tried to recreate your shed MP from scratch but I quickly ran into issues where the model did not match up with the image. This kind of makes me wonder if the image was cropped or if a different focal length was used to take the different photos… where they? Match Photo seems to like really dumb, straight-on, non-cropped images. Something to do with algorithms and perspective math.

I thought I made a video at one time describing what you are trying to do. I will see if I can’t dig that up.