Camera matching with the following picture

[pentexplorer]

Hi guys,

 

I have attached a picture that I would like to know how you guys do camera matching normally in architecture visualizations. I have already done a sample but I am not sure I am doing it the right way. I am supposed to camera match with some 3D people in the scene with shadows cast and pan it across to incorporate this footage into a video.

 

Original Image (The original pic is taken by a Nikon D100 and 12mm lens.):

 

I have set the perspective lines as the horizon here. I am following the horizon from here.

 

 

And this is what I got from Max trying to camera match it by trial and error.

 

The 2 smaller cylinders at the side are about 0.8m height and the one at the door and the front is at 1.75m height.

 

Viewport View of my scene (used the center rectangle space as guessing of 4m wide apart)

 

 

Not sure I am doing it the right way.. I just throw the image into the viewport background and also the environment background and draw a plane on the perspective and try to match it from there. I tried to follow the 3DTotal tutorial but couldn't really get it working on mine. Probably my picture has very few perspective indications? What other perspective lines can I get frm this image? Thanks in advance!

[Tommy L]

Its best if you have some dimensions that you know are correct in the photograph, at least one. Otherwise you have nothing for reference.

[pentexplorer]

Hey there tommy,

 

seems that I have no clear indication of any dimensions so yeah you can say that I don't have anything for reference. Just trial and error by guessing. What other perspective indications can I know from the photograph? Was my horizon indication correct after all? I guess I will stick with this and use the following reference.

[Tommy L]

Just re-read your post. You'll have difculty panning across with 3d elements in the scene as the perspective will not shift in the photo. I think you will have to animate the thing as a static scene (dont pan camera) then do the pan in post. Wil stil look a little wierd but if its a quick shot then you should get away with it.

Your horizon looks correct. I would try doing the scene as an animation and make sure the whole thing is going to work before you worry too much about the cameras etc. When you see discrepancies in the test animation then you will know what to correct. Its easier than trying to cover all bases from the outset.

[3dp]

looks to me you are on the right lines

i soon leaned to ignore the max camera match utility

i oftern get photos that are not taken by myself to match so as you have done here a overmark image in max can set you up

 

http://homepage.ntlworld.com/sjleworthy/wp-02/front.html

 

however getting into doing it by eye may still be the only way to go if you have a backplate that has been modified by using a stitiching programme for example

[pentexplorer]

Thanks 3dp...your article was a great read! May I know why you dont use the matte shadow material on the plane?

 

I have not tried to experiment with the camera match utility but I think doing it by eye and trial and error is the best way...can anyone link me some good read on judging perspective lines and horizon techniques on a photograph? Thanks.

[Tommy L]

Camera match facility is a very useful tool. However, you do nee to know some accurate measurements in the scene and you also need a to know the history of the photograph.

[JonRashid]

I would create an accurate 2d board of the building and texture with the photograph. This would leave only the awning to be reproduced in 3d and then drop sky the behind. This would allow you to pan across the "photo/board" without too many problems. The majority of the image is in only one plane so should be straightforward to do. This would also allow shadows etc to retain their perspective as you move across the model. Providing a bit more realism than simple post pan.

[pentexplorer]

Hi guys,

 

I managed to do the camera matching and this is what should be final I guess. Used vray to render and composited the channels in after effects to do a panning animation.

 

 

 

Let me know any comments or critiques. Thanks.

 

This is the original picture.

 

Edited March 26, 2009 by pentexplorer

[Tommy L]

Looks great. One other thing you have to look out for is the conversion multiplier for a camera that does not have a full body. I dont know about a Nikon D100, whether its full frame or not.

[pentexplorer]

Looks great. One other thing you have to look out for is the conversion multiplier for a camera that does not have a full body. I dont know about a Nikon D100, whether its full frame or not.

 

I think the D100 is not a full frame one...did check out in google and it was not full-frame..only the d700 and d3s are full frame. Sorry but what you mean by conversion multiplier? Conversion from 35mm film? Btw this picture was from google images and luckily I could see the camera properties still intact in the summary page of the image.

[Tommy L]

Do some reading on DSLR. Thing is, the mm of a lens is only accurate if used with a 35mm body. Because the sensor of some digital cameras are smaller, they need a multiplier to give the correct length of lens. I think its 1.6. So a 12mm x 1.6 would give you the lens (18mm-ish).

However, if this is a google image, you do not know if its been cropped, which will affect the camera match.

I think when you dont know the details, you just have to guesstimate. I think you've done a good job of that here.

[pentexplorer]

Oh thanks..I do see it now...but since that D100 is a pretty old model, it probably needed to have a multiplier to output the correct focal length. I think its also quite hard to tell since it was from google imagery. Hence the image could have been cropped or modified though it does not look like it was.

 

Here's the viewport view of my render: