Smoothing a 3d curve

ETHAN_KIDD

Hello,

I am struggling to attempt to figure out how to smooth this given curve I have created. It was made using an arc and a projected curve attached to a straight line, meaning that I cannot simply fillet it or something of the sort. How could I properly smooth this line to create an organic sweep path?

EvanReese

I'm glad you got something that works how you want, but I feel sure there's a better way. Does this do what you need?
https://cad.onshape.com/documents/9a5d0197acaa34d0db828f01/w/88eead3c3b83d131c9e9cba0/e/eec57f22edecd8d913909c0c

EvanReese

Maybe you could just use Freeform Spline, and visually match close to these? Or you could snap points to your existing curves, and use the Control Points mode probably.

ETHAN_KIDD

That would In theory work, but I already tried that and after tweaking around again I could not manage to get the created spline close enough to the edges of the actual sketch, even after adding weight. This project is just too specific for something so free form to be useful.

EvanReese

you could make a sphere at the corner vertex to split back both curves and use Bridging Curve to blend them

EMBASSY_DESIGN

Either, a arc tangent to the line at one end and tangent to a point on the arc (not the end point) at the other (trim arc).
Or,
a spline with only two points, each tangent to the line/arc at each end (if you need the whole arc) then dimension the tangency of the spline for total control.   Bridging curves do something similar but are more suited to turns in 3d.  This appears to be a 2D sketch,
You may then want to make a composite curve from the 3 items.
 M

ETHAN_KIDD

That would In theory work, but I already tried that and after tweaking around again I could not manage to get the created spline close enough to the edges of the actual sketch, even after adding weight. This project is just too specific for something so free form to be useful.

I did however find a different way to do this same idea of a 3d curve with specific dimensions using the helix tool
and a 3d extrusion

The goal of this sketch is to create an extrusion path for a handrail of a stair, so it had to be this specific, and also tangent. If wanted, I'll post a version of this with easy to understand variables for custom things, as this sketch took about 3 days to make and I don't want anyone else going through this hell.

NeilCooke

You can't do it through the UI, but a simple script will do it
https://forum.onshape.com/discussion/20638/improvements-to-onshape-april-12th-2023/p1
https://cad.onshape.com/documents/5e7b129d3112105f68f9ed86/w/3a45d529de437cf5951ac230/e/f04f96bd5c4a804df637a392

EvanReese

I'm glad you got something that works how you want, but I feel sure there's a better way. Does this do what you need?
https://cad.onshape.com/documents/9a5d0197acaa34d0db828f01/w/88eead3c3b83d131c9e9cba0/e/eec57f22edecd8d913909c0c

S1mon

This reminded me that a trim option for Bridging curve would be very nice. 

Vote here

JosefBurjeta

Ethan, I think you misunderstood the definition of an arc - it's a circular section. So in your case - it cannot add tangent connection to the defined half circle on the left and yet continue tangent on the straight line on the right. Those tangencies have no intersection point (two horizontal lines). In red, there are marked tangencies from Arc which meet in one point.


You have two options, either keep the starting point in the end of half circle on the left and with keeping it tangent, you can use eg. Bezier curve to achieve tangency on both ends. It will create orange curve, which has tangency marked in yellow and has two Radiuses.


Or the second option is to move start from the end point of half circle on the left. Keeping the Arc (control point marked in grey) tangent to the circle on the left will automatically create point, where it meets with straight line tangency from the right. There's also option to use eg. Bezier curve (with black control points) and fiddle with the starting position on the left, so it moves more to the previously selected point and will not "eat up" a lot of red part of the circle.