I thought I had this right, but some testing has given unwanted results.
Here is what I have:
// camera forwards the calls to its quaternion
m_camera->RotateYaw(DegreeToRadian(45.0f));
m_camera->RotatePitch(DegreeToRadian(15.0f));
//------------------------------------------------
//------------------------------------------------
void Quaternion::RotateYaw(float a_theta)
{
Vector3 l_axis_y;
GetAxisY(l_axis_y); // gets this quaternions Y-axis
RotateAroundAxis(a_theta, &l_axis_y);
}
//------------------------------------------------
//------------------------------------------------
void Quaternion::RotatePitch(float a_theta)
{
Vector3 l_axis_x;
GetAxisX(l_axis_x); // gets this quaternions X-axis
RotateAroundAxis(a_theta, &l_axis_x);
}
//------------------------------------------------
//------------------------------------------------
void Quaternion::RotateAroundAxis(float a_theta, const Vector3* a_axis)
{
Quaternion l_quat;
l_quat.x = a_axis->x * sin(a_theta * 0.5f);
l_quat.y = a_axis->y * sin(a_theta * 0.5f);
l_quat.z = a_axis->z * sin(a_theta * 0.5f);
l_quat.w = cos(a_theta * 0.5f);
(*this) *= l_quat;
}
This code I would have expected to work like normal euler angle rotation, and the result should have been a camera pitched slightly, without any tilt. But there is a tilt (
http://www.mercenaries.ws/tiltedquat.jpg), which I don't understand.
When I rotateYaw() alone, I have no problem. I always have a problem with pitch, however, no matter if I do pitch alone or not, or in what order I call it.
What am I doing wrong?
Edit: Oh, btw, I will provide the GetX(), GetY() and GetZ() methods as well, just in case it will become interesting.
//------------------------------------------------
//------------------------------------------------
void Quaternion::GetAxisX(Vector3& a_axis_x) const
{
//Real fTx = 2.0*x;
float fTy = 2.0f*y;
float fTz = 2.0f*z;
float fTwy = fTy*w;
float fTwz = fTz*w;
float fTxy = fTy*x;
float fTxz = fTz*x;
float fTyy = fTy*y;
float fTzz = fTz*z;
a_axis_x.Set(1.0f-(fTyy+fTzz), fTxy+fTwz, fTxz-fTwy);
}
//------------------------------------------------
//------------------------------------------------
void Quaternion::GetAxisY(Vector3& a_axis_y) const
{
float fTx = 2.0f*x;
float fTy = 2.0f*y;
float fTz = 2.0f*z;
float fTwx = fTx*w;
float fTwz = fTz*w;
float fTxx = fTx*x;
float fTxy = fTy*x;
float fTyz = fTz*y;
float fTzz = fTz*z;
a_axis_y.Set(fTxy-fTwz, 1.0f-(fTxx+fTzz), fTyz+fTwx);
}
//------------------------------------------------
//------------------------------------------------
void Quaternion::GetAxisZ(Vector3& a_axis_z) const
{
float fTx = 2.0f*x;
float fTy = 2.0f*y;
float fTz = 2.0f*z;
float fTwx = fTx*w;
float fTwy = fTy*w;
float fTxx = fTx*x;
float fTxz = fTz*x;
float fTyy = fTy*y;
float fTyz = fTz*y;
a_axis_z.Set(fTxz+fTwy, fTyz-fTwx, 1.0f-(fTxx+fTyy));
}
Quote:CalvinI am only polite because I don't know enough foul languageQuote:Original post by superpigI think the reason your rating has dropped so much, Mercenarey, is that you come across as an arrogant asshole.
