Given the data passed into glm::lookAt(), one can construct some useful vectors for viewing.

• The viewVector = viewPoint – eyePoint
• The strafeVector = viewVector x upVector
• The orthogonal upVector = strafeVector x viewVector.  This may be needed if the upVector is not orthogonal to the viewVector.

Typically, one normalises these vectors.

Moving the camera along the

• viewVector makes the camera move forwards/backwards
• strafeVector makes the camera move right/left
• orthogonal upVector makes the camera move up/down

High