points are not at the right XYZ value

Hi,

Just playing with points in my model and see  when I label coordinates from my DGN file and fill this in by points (point 2) , it's moved to the right.

When review the new point (Point 1) with label coordinates it's a different coordinate!

Parents
  • Hi Christiaan,

    From the screen shot it is not obvious what is or goes wrong.

    Without additional information, my observations are: point1 is by projection onto a curve. This may be the main reason for the difference between point2 and point1. If a point is projected onto a curve this would be the expected result. Given the shown values, if those are in mm, then the differences are still well within common construction tolerances. In addition, if the coordinate values are in mm, then they are outside of the Solid Area, which may further affect accuracy of geometric operations.

    For better analysis of why this deviation exists, please attach the corresponding files that contain the geometry and the GC script.

    Thank you,

         Volker

       

  • Hi Christiaan,

    Thank you for sending the files. It looks like the curve onto which point1 is projected is elevated from and not parallel to the design file's XY-plane. Therefore, in an orthogonal Top view projection, there is the deviation that you captured in your screen shot. point2's Z-value is 24.831, so only a slight slope in the curve will cause a visible distance between the two points, just like shown. point1 is projected perpendicular to the sloping curve which means that the projection vector is angled from the vertical orientation of the Top view projection (and the Z-vector of the design file's coordinate system).

    I hope this makes sense.

    If a vertical projection of point1 from its XY-plane location onto the curve is needed, there is a huge probability that no intersection will be found due to inaccuracies in the double (im)precision computation employed in electronic computing.

    Therefore, a better approach would be to place a vertical plane through point1 and then find its intersection with the curve. This does in fact create the desired result of the intersection point on the curve coinciding with point1 on the XY-plane when viewed in an orthogonally projected Top view.

    Best success with your project,

         Volker

       

Reply
  • Hi Christiaan,

    Thank you for sending the files. It looks like the curve onto which point1 is projected is elevated from and not parallel to the design file's XY-plane. Therefore, in an orthogonal Top view projection, there is the deviation that you captured in your screen shot. point2's Z-value is 24.831, so only a slight slope in the curve will cause a visible distance between the two points, just like shown. point1 is projected perpendicular to the sloping curve which means that the projection vector is angled from the vertical orientation of the Top view projection (and the Z-vector of the design file's coordinate system).

    I hope this makes sense.

    If a vertical projection of point1 from its XY-plane location onto the curve is needed, there is a huge probability that no intersection will be found due to inaccuracies in the double (im)precision computation employed in electronic computing.

    Therefore, a better approach would be to place a vertical plane through point1 and then find its intersection with the curve. This does in fact create the desired result of the intersection point on the curve coinciding with point1 on the XY-plane when viewed in an orthogonally projected Top view.

    Best success with your project,

         Volker

       

Children
No Data