Define distance isn't changing calculated distance

Answered

Comments

3 comments

  • Avatar
    Summer Scott

    So in reading a little more if the camera such as a drone provides GPS the model will scale based off the GPS. 
    Now my drone photos GPS points have always deviated significantly in many different ways. Now I did use two different drones so I have wondered if for example their altimeters were calibrated differently but regardless they skew considerably on x and y as well. I didn't care much because I got everything aligned although I do wonder if this was why it was so hard to do so. But if it is going to screw with my scale this is definitely something I need to resolve.

    0
    Comment actions Permalink
  • Avatar
    Lucia CR

    hello and welcome, what version of RealityCapture are you using and how does it behave when you define more distance constraints at once?

    0
    Comment actions Permalink
  • Avatar
    Not_Nick

    Hi Summer,

     

    The residule error lines in that screenshot aren't that uncommon for UAV photos. Always a bit of disagreement between the original GPS position and what RC has figured out from photogrammetry. Especially if you used two different UAVs. Generally altitude is pretty hit and miss for GPS.

    That aside.

    Your added in tie points with scaling have to compete against all those GPS points. That is, the manual tie points with the set scale add are trying to influence the scale of the overall model but then so are those 2,000 photos all with GPS points.

    So what you're finding is RC is trying to find a solution that satisfies the condition of the manual tie points you set but in the end the 2000 GPS points have more weighting.

    So you can either increase the "weighting" for the manual tie points or disable some or all of the GPS for the photos (can be done within RC). Either of those solutions will relax the amount of points influencing the scale of the model and hopefully let your manual points have a bit more influence and get a value closer to what you are inputting.

     

    0
    Comment actions Permalink

Please sign in to leave a comment.