The right Camera perspective…

[koffiekoekje]

Hello :hello:

On this moment I’m working on a project with a bear witch is falling from the stairs, to learn how to combine 2D pictures with a 3D animation.

To do this I have attached image planes (pictures of the stairway) to different cameras. By doing this I can align the pictures to the model. At least, that is what supposed to happen.

The pictures are taken with a digital camera (35mm) and a lens with the following specs.
Angle of view: 76
Aperture: 18mm

(Pictures are cropped to 720x 576 px PAL) (also export format in maya)

I also changed de camera settings in maya but I can’t get the perspective right. It seems that the image has a different perspective than the maya cam.

How and what can I change on the camera in maya to get a better alignment?

I hope you all understand my problem...
http://i86.photobucket.com/albums/k117/koffiekoekje/stairs.jpg

[laxman]

Generally what you need to do is set up the camera first and then create the geometry. That way it will match perfectly and any perspective problems will fix themselves. So if you can't get it to work, you will have to remake the stairs based on the camera view you now have. That will make sure they match 100%.

Now, i'm pretty sure maya uses a three point perspective view for the perspective camera. As for changing the perspective, I don't think you can change a perspective camera to something like an isometric or trimetric view with a setting but ti is possible. Now based on the picture it doesn't look like the picture was taken from a specific 'perspective' but that doesn't matter. It is possible to match the camera by one of two ways:

1) This should be possible, i've matched a few image planes before and never found it impossible to do. Just keep playing around with the camera, either rotating it slightly or zooming in or out. Theoretically it should be possible for the perspective camera to match any view.

2) If that doesn't seem to be working you could create an orthographic camera and move it into place. So what you would do is lets say define the piece of wood on the side of the staircase (shown upper left in the picture) as the front face. Then from that you would 'guesstimate' about how far the camera is physically from that face and you would move back that much (from the geometry you have already created). Then set the pivot point on the geometry, on the face, and guesstimate how degrees you rotated to the right to get the camera where it is, and you would rotate the orthographic camera by that much (in the y axis). Then estimate how many degrees you rotated the camera upwards (looks like its very small) and you would rotate by that much.

So IF the geometry is perfectly dimensioned (i'd suggest measuring to find out cause it will save a lot of headache) then the orthographic camera will be able to match it cause all perspective views can be defined from an orthographic view.

BTW, anytime you are doing live action matching or image plane matching or even any animation in general, its always a good idea to set up the camera first. If will save a lot of time in the end.

[koffiekoekje]

http://images.fok.nl/s/thumbsup.gif Thank u verry much. It starting to align pritty wel. Option 1 did the trick. Ignorance of the camera tools was the problem... http://images.fok.nl/s/bloos.gif

Now I'm gonna tweak, tune and drink more coffee http://images.fok.nl/s/koffie.gif