Projected curves not aligned with input curves


Normally when I use the ‘project’ command, the output curves line up perfectly with the input curves when viewed from the Top viewport. However, I’m currently having an issue where the output curves are slightly off alignment.

I’ve attached a screenshot and the Rhino file.

Thanks in advance for any assistance,

170318_Project_Alignment_Issue.3dm (253.9 KB)

Hi Matthew,

The object is over 4 million units away from the file origin. This causes calculations (like projecting) to loose accuracy.
Try to (temporarily) move your objects towards the origin and projection will again fall within file tolerance.



you are working with unitsystem meters and a tolerance of 0.01 meters. Your model is 5067285 meters away from the world origin. If you move the model to the world origin, and slightly reduce the the tolerance eg. to 0.001 (equals 1 mm) the projection looks better.


Thanks @clement and @Willem ,

That worked perfectly!

The surface I was trying to project onto was made from contour lines I’d imported from a DWG CAD file. So the DWG file must have imported at over 4 million units away from the origin.

Thank again :slight_smile: