Matching real camera with SU camera
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It would be the equivalent of cropping the image from the 35mm negative/slide. Much like those 35mm cameras with the panoramic setting. They just put a mask over the film to change the shape of the recorded image area.
So if your drawing window is proportional 30 x 24 you would be cropping a bit off the ends. Or, if it is proportional to 36 x 20, you'd be cropping top and bottom.
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If I use a plugin to change the aspect ratio of the camera to 1.5 and set the Focal Length to 117mm I get the exact same view as taking the vertical AOV and entering into SU ( 11.7deg ) without setting the aspect ratio.
I used this calculator to get the AOV from the 35mm focal length.
http://www.tawbaware.com/maxlyons/calc.htm -
If I take that photo and add it as background in SU - then I need to apply lens correction in order to match the scene?
I have a model where I've done all this for three scenes - and it has worked great. But I have trouble with this fourth one...
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Hi Thom,
Have you tried PhotoMatch (the "reversed" way)? See Matching (existing) models to photos
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Yea - it's a horrible tool to use.
I never ever have a pretty, neat photo reference like they show in their examples.
Right now I'm matching a large siteplan - I have no long clear building edges to follow.
And even if I have a single building to match - it rarely have any square corners I can use - nor is the perspective PhotoMatch requires ever the one I want.I wish we can photomatching like other apps do it - 3dsmax, Bonzai, Vector works - pick reference points in model and pick matching points in image - then have the computer resolve the camera match. None of this awkward fiddling around with handles that offer little control.
I've found more and more that it'd faster to just match the SU camera properties with the camera that took the photo and do it by eye with the normal camera tools.
(yea - you struck a pet peeve of mine in regard to SketchUp)
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I do not like to use that tool myself either (probably because of the same reason - lack of good reference photo).
Then I generally just "eye ball" the Match - put it inas a fixed background and use the Zoom (and with Shift, the FOV) tool to adjust everything. If needed, Orbit/Pan is at hand so you need not even exit the same (shift) Zoom tool.
I "matched" the below photo of the Trier basilica with my model of our basilica here this way:
YouTube - The Basilicas in Sopianae and Augusta Treverorum
[flash=480,385:3fjqoz16]http://www.youtube.com/v/YBF6rJIhTnQ?fs=1&hl=en_US[/flash:3fjqoz16] -
It appears to me that PhotoMatch was design to model from Photo - or texture from Photo.
I, rather, want to insert our projects into existing situations.And it's not too uncommon that I do things like this - for the planning department at our office. Here the slightest adjustment makes a huge difference.
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Thomthom,
Is the fourth photo that is giving you trouble by chance more vertical than then other three photos? The reason I ask, is that I used to use images as a watermark on a scene that I wanted to register to my model geometry. The model and the watermark image stayed in sync so long as the aspect ratio of my display windows was wider than the aspect ratio of my watermark images. That is to say that there are bars on the left and right of my image that I can then crop later in photoshop. If I changed the aspect ratio of my display to be taller than my watermark image (now there are white bars at the top and bottom of my image) things go really bad.
I attributed this to the fact that while my model is still resizing based on the vertical AOC of my model, my watermark image is now resizing based on the horizontal AOC of the watermark photo. I never liked how this works, they should always both resize in the same way and stay in sync.
An alternative to trying to setup your SketchUp windows correctly is to use Layout where you have more control of the aspect ratio.
An interesting thought I had to aid in lining up your camera view is to add points into SketchUp based on google Earth data for other buildigns that appear in the photo, or even points on the distant mountains, but I suspect if you pull in points too far from your origin SketchUp won't like it. I wouldn't trust generic GoogleEarth buildings, but if you could make BuildingMaker buildings they would be very reliable, although I don't think you have BuildingMaker in your area yet?
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Aspect ratio and pixel size is exactly identical for all photos.
I made it work by adjusting the AOV to 11.0deg instead of 11.7.
@davidboulder said:
An interesting thought I had to aid in lining up your camera view is to add points into SketchUp based on google Earth data for other buildigns that appear in the photo, or even points on the distant mountains, but I suspect if you pull in points too far from your origin SketchUp won't like it. I wouldn't trust generic GoogleEarth buildings, but if you could make BuildingMaker buildings they would be very reliable, although I don't think you have BuildingMaker in your area yet?
I have a very detailed 3d site plan - better detail that Google Earth data. (Google got poor data for Norway btw). The building masses you see in my last screenshot where made from that plan.
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@unknownuser said:
Thomthom said: And it's not too uncommon that I do things like this
indeed very often!
you remember this post?http://forums.sketchucation.com/viewtopic.php?f=15&t=16074&p=138497&hilit=photo+match+davide#p138497 -
The FOV in SU is measured quite differently than in traditional film cameras. In film cameras, it is measured along the diagonal of the film frame, and in SU it denotes the vertical viewing angle. So a SU camera of a given focal length always has a wider viewing angle than a physical camera.
Anssi
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that's some useful info, anssi. thanks
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Just remember that perspective does not vary with focal length. Perspective varies as the camera to subject distance and angle changes.
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