camera position

Dear All,

Please explain how should I calculate the camera parameters to capture whole object with any size (zoom all command) :

- For example, I have a mesh with object center at xo,yo,zo and with object size A

- I want to put camera at xc,yc,zc
- How do I calculate xc,yc,zc and DepthofView and FocalLength to get the whole scene on viewport?

Thanks for your advice.
Nathan

http://www.opengl.org/resources/faq/technical/viewing.htm#view0070