some 3D layer issues.

[Malcolm Desoto]

“the easiest way would be to try and keep your 3d camera at the same (or very simialr) angle as the camera that shot the subject… or reshoot the subject with the camera angles you want in the 3d comp.”

I agree. That is what I’d do in the ideal situation. The only catch is that the camera needs to fly around the room in some extreme angles.

Really Railboy? That would be a fantastic little trick! I’ll have to give that a try sometime.

[Malcolm Desoto]

Oh, and I did try rotating the room Roland. I just couldn’t get the perspectives to look right though.

Thanks for your help though. This is all good info for creating a 3D project work flow.

[Adam Taylor]

having looked at your image again, there are a couple of obvious problems. Aside from the obviously different focal lengths used, the photo was taken with the camera positioned above/looking slightly down at the couple, and your comp has the camera looking from upwards from below.

Unless you put the comp camera in roughly the same position as the practical camera, you will not get a convincing image, as nothing will be on the same plane.

You mentioned you could not get the perspectives right….well perspective tends to be created by a combination of the camera’s focal length AND the angle of the subject relative to the camera. Get those right and you will be on your way to getting the shot thats in your mind.

adam

Editor/Mixer
Character Options Ltd
Oldham, UK

[Malcolm Desoto]

Thanks Adam.

These will all be things to take into consideration on the next project. Unfortunately I can’t reshoot any material at this point and the camera has to be in that position.

This has all been a huge learning experience and I suspect that the next 3D project will go alot smoother.

[Sam Moulton]

Camera position always determines perspective. For this to work your camera position has to be the same. Focal length controls the field of view and has nothing at all to do with perspective except when lenses have inherent distortion. This is most common with wide angle lenses.

It’s actually fairly easy to determine approximate camera position if the image has not been cropped and there is something in the image at right angles to the floor. In your case I’d cut out your people, make the layer 3D, Add a camera with a normal lens, add an adjustment layer and place it below the dancers, add a 3D solid, rotate it on the X axis 90

[Sam Moulton]

forgot to add that the 3d layer of your dancers needs to have auto orientation set to orient to camera. This technique will not work without this setting.

[Malcolm Desoto]

Thanks for the input. I’ll definitely give it a try.