Camera Calibration using Perspective Views of Rectangles

Thanks, Perhaps that one ii posted earlier. The one with the pool, i think i got it quite good. BUt like to see you approach, for you they are puzzles :slight_smile: So that means fun!

I think the one with the pool has a distorted perspective, maybe it is a panoramic projection or a composition or the “bar”-structure doesn’t have right angles or a combination of these possibilities?

The green lines show difference in perspective. Cyan and magenta lines are vanishing lines.

The vanishing lines of both objects don’t match. If it was only a rotation of the one building in relation to the other building, then the rotated viewpoint circle would cross with the other viewpoint circle. Now the one viewpoint circle lies totally within the other viewpoint circle. Perhaps there is no exact solution here.

So I think your scene is optimal with the tools/add-ons that we have here. :wink:

Well this shot is a render and it was bugging me a lot. I first tried BLAM on this shot and after done i tried manually adjusting it to get the best position as in the short. Im not sure i tried it with this addon. I did want to remodel everything :slight_smile:

First i thought you had some other calculation process, but you simple draw all lines to view the vanishing points. This show the image is quite weird. I even got the feeling its a montage of different shots. Because i could get one building (big right one) sort of the same. But that fitness place would be completly out of line and scale. The angle of the roof where freaking me out. But you drawing shows exactly why.

Thanks for!

I have problem with one focal point image where x and z exactly parallel. This happens with lots of architectural images. I can not make this situation to work, tried all 3 method provided. Need help indeed, thanks guy.

You may be better off trying Blam! for this, or even do it “manually”. If you can figure out the dimensions of the doors and the height of the counter roughly, you can scale cube placers accordingly then alter the camera angle by hand.

In difficult cases I always use SketchUp and Sketchup (SKP) importer addon.
After importing scene, you need to adjust camera resolution the same as in the picture.

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Can you recommend a page showing that process in detail? Looks highly effective.

After adjusting camera to the image in the sketchup simply save the entire scene as *.skp file and import it to blender using Sketchup importer.


Many Thanks, will look at that. :slight_smile:

I found out blam add on works perfectly on this situation, just use one focal point method. So I guess I will keep both add on for specific cases.

But thanks for your reply. Appreciate a lot. Kinda newcomer for blender but already fall in love it.

Oh definitely keep both, you’ll find one works well over another more often than not. :slight_smile:

this is the result of this amazing add-on, at first it was hard all I did is trial and error and eventually decided to hit the Solve Focal+Y because the image is made from other software which has tilt shift camera to perfectly align the vertical and horizontal and the add-on didn’t allow you to have straighten if its Solve Focal so you need to choose Solve Focal+Y and from there you can model your architecture and later just adjust something that didn’t align.

ps. the ceiling and flooring of my interior hallway when have focal is not align so i adjusted it. here is the result without shader. all in all it was great experience and this is my first time to succeed doing this.

Hi Guys,
I think I need your advise. I’m trying to calibrate camera to below photo, but after many tries still with no success.
If I set manually camera as Full Frame prior to calibrating - it gets re-set to 32mm auto afterwards. Is there an option to preserve these settings? Are they included in calculations?
And the most important, I didn’t succeed to get proper focal length. 3dmax camera match (which seems to give reliable results in majority of cases) sets it to ~130mm, and PVR was each time setting it between 18 and 50mm.
Can you please share some hints? Is this one of those problematic photos which can not be calibrated correctly?

Hello blndusr, I played with your image:

With some descriptive geometry, I found the perspective. I made a help-image for you. Now you can use the red rectangles. Solve with: “Solve Focal+Y”.

interior.blend (437.5 KB)

I used the same method here:

I hope this is helpful.

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Thank you Iarga! It seems quite complex at the first glance, I need to read through it and practice to get some understanding.
Focal length 70mm, as you have set it, is too low for this interior. Objects made with this value are too flat. I already made the model, and 130mm seems to match perfectly.

@marcor, do you still work on this add-on? Are you going to make an update for 2.80?

Hi. Once 2.80 is out, why not?

And it is now! In beta anyway, but many are updating their add-ons. :smiling_face_with_three_hearts:

I just watched a tut from B-guru and he said somthing about the dev people behind BLAM, which got this addon started, made something new called fSpy. Holy shit does that look cool, sort of like the Sketchup method, with interactive adjustments

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