roll :: Float -> Camera -> Camera
roll theta c@(Camera r _ _ _) = (rotation .~ r') $ c
  where r' = axisAngle (V3 0 0 1) theta * r

-- |Add a vector to a 'Camera''s current velocity.
roll :: Float -> Camera -> Camera
roll theta c@(Camera r _ _ _) = (rotation .~ r') $ c
  where r' = axisAngle (V3 0 0 1) theta * r

-- |Add a vector to a 'Camera''s current velocity.
roll theta c@(Camera r _ _ _) = (rotation .~ r') $ c
  where r' = axisAngle (V3 0 0 1) theta * r

-- |Add a vector to a 'Camera''s current velocity.