# Measuring length of curves on an STL of shoe

Hi all! I’m trying to figure out how to split the STL images of a few shoes I’ve scanned into points, so as to measure the distance between a few critical points on the scan (i.e. I’m trying to measure the length of the spline from a point on the very back of the insole to a point on the tip of the toe of the insole). Any advice as to how I can go about this?

I’ve attached an image below of one of the shoes for reference.

You can use the Distance command together with the Vertex osnap to measure between specific points on the mesh.

Thanks for the tip! Just to be sure, can I use this feature to measure the entire length of the spline between two points rather than just the 2D X-Y distance from one point to the next?

There is no spline to measure.
An STL is just a dumb, triangular mesh.
All there is in a mesh are the flat mesh facets and the vertex points at the facet corners.

Hi Natalie- A mesh will not have any curves to measure - you’ll need to project curves onto the mesh, something like that, and then measure the result. Does that make sense with what you want to do?

-Pascal

Yes! How can I go about projecting curves onto the mesh?

Hi Natalie - the simplest way is to create the curve as a 2d curve in whatever view you like, then use the Project command in that view. Note Project uses the current construction plane normal as the direction to project. You make like SubCrv as well to create a smaller version of the projected curve- you can start and stop the projected curve, so to speak, exactly where you want it on the mesh.

-Pascal