Camera rotation using quaternions

How do I specify the rotation of a camera using quaternions about an axis at a specified angle. I know how to rotate about individual axis, but what if I wanted the camera to rotate about all three i:e: u,v and n axis about the eye.
I am programming in C++ using OpenGL.

Thanks.
deol_bhajiAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

jadeccCommented:
Hi,

I wish I could claim that I completely understood quaternions. What I had to do was keep up with the values (in degrees) of the heading (u), pitch (v), and roll (n) of the camera.  Then I created a quaternion from each of these angles and used them to figure out the view and driection of the camera:


      //quaternions that represent rotation
      m_qHeading.CreateFromAxisAngle(0.0f, 1.0f, 0.0f, m_HeadingDegrees);
      m_qPitch.CreateFromAxisAngle(1.0f, 0.0f, 0.0f, m_PitchDegrees);
      m_qRoll.CreateFromAxisAngle(0.0f, 0.0f, 1.0f, m_RollDegrees);
      
      //combine pitch and heading and roll and put into quaternion q
      q = m_qPitch * m_qHeading * m_qRoll;
      q.CreateMatrix(Matrix);
      
      // set our new perspective
      glMultMatrixf(Matrix);
      
      //get the y coord for our direction from the pitch quaternion
      m_qPitch.CreateMatrix(Matrix);
      m_qDirection.y = Matrix[9];
      ypitch = Matrix[9];
            
      //combine heading and pitch rotations to get the x and z coords for our direction
      q = m_qHeading * m_qPitch;
      q.CreateMatrix(Matrix);
      m_qDirection.x = Matrix[8];
      m_qDirection.z = Matrix[10];      


For a better explanation than I can offer check this link: http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=Quaternion_Camera_Class

I hope that helps you more than hinders you:-)
jadecc
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
bcladdCommented:
deol_bhaji - Did jadecc answer your question? Do you need more or different information?

-bcl
0
deol_bhajiAuthor Commented:
Thank you Jadecc. The link you sent was quite helpful. I guess I need to study a bit more on quaternions first.
deol_bhaji.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Game Programming

From novice to tech pro — start learning today.