important camera attributes in maya?

#1

Hello,

I have a couple of questions I´ve been thinking of for a while that I need to straighten out. When importing boujou data into maya, I get a camera and some locators. For the camera to represent the real camera it needs the exact same attributes, so what are those? What´s the attributes I need to change in maya?

-Focal length?(I guess I set that in boujou, right?)
-the “angel of view”-attribute? is this important, and where can I see this, is it called the same on a real camera?
-film gate? is this one important?
-camera aperture? I have 2 values to insert here, where can I see this on a real camera?

I understand that it´s very hard for someone to just answer these questions so everything becomes clear, so if anyone know a good tutorial or anything where they go deep into this, I would really appreciate it!

I´ve been googling this some times but haven´t found a good answer for it.

Best regards/Jim

#2

Film gate (aka sensor size). Maya refers to this as the camera aperture (the two values in Maya are the width and height of the gate in inches).

In film, the gate is used to mask the incoming image on the film negative. So that it creates a solid image frame.

http://home.earthlink.net/~lkless/Canyon/projector.jpg

You can change the size of the gate to create different aspect ratios. This shows the difference between a 16mm gate and a super16mm gate - the super16 gate creates a frame with a wider aspect ratio.

http://www.k3camera.com/k3/images_parts/k3gates.jpg

Using the focal length and film gate size you can calculate the angle-of-view of the camera. This is so your perspective matches between the real camera and the maya camera.

You also need to take into account lens distortion.

#3

You need to provide these camera info to your Tracking Software NOT Maya
Your lense Focal Length and your film back (sensor size) and frame rate (24fps, 23.98, 30, etc)

once you put this in boujou or pftrack and EXPORT to maya you DO NOT change those values again or your track will go crazy!
again, these values need to be provided in your tracking software before hand. As a matter of fact Maya will lock those nodes so you wont touch’em!

#4

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