打开GL旋转：旋转超过90度时查看“跳跃”

Question

我使用以下代码来执行偏航/俯仰旋转：

- (void)rotateCameraUsingYaw:(double)yaw andPitch:(double)pitch
{
    GLKVector3 centerToEyeVec = [self centerToEyeVec];
    GLKVector3 rightVector = GLKVector3Normalize(GLKVector3Normalize(GLKVector3CrossProduct(centerToEyeVec, self.up)));

    GLKMatrix4 yawRotationMatrix = GLKMatrix4MakeRotation(yaw, self.up.x, self.up.y, self.up.z);
    GLKMatrix4 pitchRotationMatrix = GLKMatrix4MakeRotation(pitch, rightVector.x, rightVector.y, rightVector.z);
    GLKMatrix4 yawPitchRotationMat = GLKMatrix4Multiply(yawRotationMatrix, pitchRotationMatrix);

    GLKVector3 newCenterToEyeVec = GLKMatrix4MultiplyVector3(yawPitchRotationMat, centerToEyeVec);

    self.eye = GLKVector3Add(self.center, newCenterToEyeVec);

    [self recalculateUpVector];
}

当音高值低于PI / 2时，此代码效果很好。当音高达到PI / 2时，模型旋转（向上旋转向量）。我不知道为什么会这样。