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RonaldSun / VI-Stereo-DSO

Direct sparse odometry combined with stereo cameras and IMU
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Alignment with Ground Truth #7

Closed RongenC closed 5 years ago

RongenC commented 5 years ago

I see that when you initialize the FirstFrame IMU (FullSystem::initFirstFrame_imu), you aligned the system with the ground truth. Does this mean that the current version of code does not able to align itself to world ground with the use of IMU data?

RonaldSun commented 5 years ago

Yes, of course. Alignment can be achieved knowing the location of the first frame. You mean the gravity direction?

RongenC commented 5 years ago

What if you do not know the first frame's location (i.e. initial true world xyz)? Gravity Direction can be retrieved directly from IMU's data right?

RonaldSun commented 5 years ago

Actually the location of first frame is set to (0,0,0). The "T_WR_align" is used to align the groundtruth to the system. So there will be a transformation between DSO's pose and world pose.

RongenC commented 5 years ago

Yes, so my question is if there is no groundtruth available for the first frame, this system unable to locate it's starting location (mainly height is relevant in this case)?

RonaldSun commented 5 years ago

Unable to lacate it's starting location

RongenC commented 5 years ago

Thank you for the clarification!