Im having some really bizzare problems with my rotation code. If I rotate at a constant one degree around yaw, the object seems to rotate 180 degrees, then go back the other way, and so on (like a metranome). If I rotate around pitch the object seems to 'wave.' I can probably provide some videos if needed.
Here is the relevant code, I'm pretty certain I've got everything correct.
Creating the rotation quaternion:
public static QuaternionF RotateAxis(Vector3F axis, float angle)
{
QuaternionF ret = QuaternionF.Identity;
float halfAngle = angle * 0.5f;
float sinA = MathFunctions.Sin(halfAngle);
ret.X = axis.X * sinA;
ret.Y = axis.Y * sinA;
ret.Z = axis.Z * sinA;
ret.W = MathFunctions.Cos(halfAngle);
return ret;
}
Turning it into a matrix:
public static Matrix4F RotationQuaternion(QuaternionF quat)
{
Matrix4F ret = new Matrix4F();
//
// Copied nicely from Axiom :)
//
float tX = 2.0f * quat.X;
float tY = 2.0f * quat.Y;
float tZ = 2.0f * quat.Z;
float tWX = quat.W * tX;
float tWY = quat.W * tY;
float tWZ = quat.W * tZ;
float tXX = quat.X * tX;
float tXY = quat.X * tY;
float tXZ = quat.X * tZ;
float tYY = quat.Y * tY;
float tYZ = quat.Y * tZ;
float tZZ = quat.Z * tZ;
ret.M11 = 1.0f - (tYY + tZZ);
ret.M12 = tXY - tWZ;
ret.M13 = tXZ + tWZ;
ret.M21 = tXY + tWZ;
ret.M22 = 1.0f - (tXX + tZZ);
ret.M23 = tYZ - tWX;
ret.M31 = tXZ - tWY;
ret.M32 = tYZ + tWX;
ret.M33 = 1.0f - (tXX + tYY);
ret.M44 = 1;
return ret;
}
And finally, setting the rotation:
public void Rotate(Vector3F rotation)
{
QuaternionF xAxis = Maths.Quaternions.RotateAxis(Vector3F.XAxis,
Maths.Functions.DegreeToRadians(rotation.X));
QuaternionF yAxis = Maths.Quaternions.RotateAxis(Vector3F.YAxis,
Maths.Functions.DegreeToRadians(rotation.Y));
QuaternionF zAxis = Maths.Quaternions.RotateAxis(Vector3F.ZAxis,
Maths.Functions.DegreeToRadians(rotation.Z));
orientation = yAxis;
this.rotation = rotation;
BuildMatrix();
}
void BuildMatrix()
{
world = Maths.Matrices.Scale(scale) *
Maths.Matrices.RotationQuaternion(orientation) *
Maths.Matrices.Translation(location);
}
public static float DegreeToRadians(float degrees)
{
return degrees * (float)(180.0f / Sharp3D.Math.Core.MathFunctions.PI);
}
