CONSTRUCTOR to initialize a Quat from 4 floats. Quat q(1,0,0,0);

CONSTRUCTOR to initialize a Quat with a scalar and a vector. Quat q(1,Vec3(0,0,0));

CONSTRUCTOR for different types. It converts a Euler Angle into a Quat. Needs to be 'explicit' because we loose fp-precision in the conversion process. Quat(Ang3(1,2,3));

CONSTRUCTOR for different types. It converts a Euler Angle into a Quat and converts between double/float. Needs to be 'explicit' because we loose fp-precision in the conversion process. Quat(Ang3r(1,2,3));

Invert quaternion. Example 1: Quat q=Quat::CreateRotationXYZ(Ang3(1,2,3)); Quat result = !q; Quat result = GetInverted(q); q.Invert();

Spherical-interpolation between unit quaternions (algebraic slerp_a). I have included this function just for the sake of completeness, because it is the only useful application to check if exp & log really work. Both slerp-functions return the same result. Example: Quat result,p,q; result.SetExpSlerp( p,q,0.3345f );

Set identity quaternion. Example: Quat q=Quat::CreateIdentity(); or q.SetIdentity(); or Quat p=Quat(IDENTITY);

Linear-interpolation between quaternions (lerp). Example: CQuaternion result,p,q; result=qlerp( p, q, 0.5f );

Linear-interpolation between unit quaternions (nlerp). In this case we convert the t-value into a 1d cubic spline to get closer to Slerp. Example: Quat result,p,q; result.SetNlerpCubic( p, q, 0.5f );

Create rotation-quaternion that rotates from one vector to another. Both vectors are assumed to be normalized. Example: Quat q=Quat::CreateRotationV0V1( v0,v1 ); q.SetRotationV0V1( v0,v1 );

Parameters

vdir

Normalized view direction.

roll

Radiant to rotate about Y-axis. Given a view-direction and a radiant to rotate about Y-axis, this function builds a 3x3 look-at quaternion using only simple vector arithmetic. This function is always using the implicit up-vector Vec3(0,0,1). The view-direction is always stored in column(1). IMPORTANT: The view-vector is assumed to be normalized, because all trig-values for the orientation are being extracted directly out of the vector. This function must NOT be called with a view-direction that is close to Vec3(0,0,1) or Vec3(0,0,-1). If one of these rules is broken, the function returns a quaternion with an undefined rotation about the Z-axis. Rotation order for the look-at-quaternion is Z-X-Y. (Zaxis=YAW / Xaxis=PITCH / Yaxis=ROLL) COORDINATE-SYSTEM z-axis ^ | | y-axis | / | / |/ +------------—> x-axis Example: Quat LookAtQuat=Quat::CreateRotationVDir( Vec3(0,1,0) ); or Quat LookAtQuat=Quat::CreateRotationVDir( Vec3(0,1,0), 0.333f );

Create rotation-quaternion that about the x-axis. Example: Quat q=Quat::CreateRotationX( radiant ); or q.SetRotationX( Ang3(1,2,3) );

Create rotation-quaternion that around the fixed coordinate axes. Example: Quat q=Quat::CreateRotationXYZ( Ang3(1,2,3) ); or q.SetRotationXYZ( Ang3(1,2,3) );

Create rotation-quaternion that about the y-axis. Example: Quat q=Quat::CreateRotationY( radiant ); or q.SetRotationY( radiant );

Create rotation-quaternion that about the z-axis. Example: Quat q=Quat::CreateRotationZ( radiant ); or q.SetRotationZ( radiant );