Surface edge problems


Hello, I am trying to model a leg from an armoire and I am having some problems blending the surface (edges) at the marked spots in the photos.

My method to get to this point was to draw 4 curves representing the shape from each view, then to make curves from cross section profile, then surface from curve network. The top block is a cube inserted in place and boolean union. Is there a better way to get the result I am looking for? Eventually I would like to try and cut this on a 4th axis machine. That is my final result I am looking for. Any help is greatly appreciated. Thank you.

armour leg 6.3dm (597.1 KB)

(Pascal Golay) #2

Hi Kevin - I am not sure it is a great idea to try to make this object from one surface, but regardless, you’d need, I think, to decide what happens at the top there - should the soft contours of the leg stay fort and intersect the box at the top where ever they hit it, or does the design require that the top edges of the leg meet the box on an exact and level rectangle? In the latter case, the leg itself will need to transition to a hard cornered thing - NetworkSrf cannot do that all in one surface.



Hi Pascal

I will need to have the square surface at the top of the leg. It would be better if the soft contours of the leg would hit the box on a straight edge for aesthetic reasons. Since you mention that making this object from one surface is not a good idea, do you have a direction that I should go in redesigning this leg?


(Pascal Golay) #4

Hi Kevin - I’d say you can build a lot of the leg as a single surface but at the top if you want to hit the box at hard edges, then there will need to be some sort of transition from soft to hard corners and that requires multiple surfaces. If I have time to fuss with it, I’ll try to come up with a workable layout - the images in the file are not too clear for the exact shape though.



Hi Pascal, I attached the 3dm file to the original post. From that you could see the curves used and the overall shape of the leg. Also there are 2 layers that have images using picture frame. I did have a straight edge/ hard corner when I first built it, but I think i did a rebuild surface and that is when it became wavy.

(Pascal Golay) #6

Right… but the tape measure obscures some crucial bits - it’s not much to go on…



Approx 16 inches tall. 2" dia circle foot. 4" sq top box.



Not exactly an answer to the problem.
But a thought.
Thinking about how to link a circle with a square.
Considering the leg a curve with a circular or half circular section shape and the top a square.
As Pascal mentioned. You have two different shapes better to consider.

Good luck


I rebuilt the curves, now left and right are symetrical and on cplane. If not using surface from curve network, any suggestions on what way to try?armour leg 9.3dm (73.3 KB)


Do you know of a way to link a circle to a square in a planer surface?


Drawing arcs, or other methods that draws curves manually
May gives more freedom designing.
To have a surface linked between a square and a circle is much more long process to obtain the surface you want (or the profil curve that generates the surface).
as the circle and the square cant meet each other directly, you need intermediar shapes to make the gap between them.

For other purposes but different geometrical process

Polygons might be helpful ?
Imagine a circle inscribed in a square, then adding two points on this circle then it becomes an hexagon, the more you add points the more it will became a circle.
Thus this will affect your profil curvature but you will have more precision and information about it.


Here was the solution I came up with. I broke each cross section curve into quads then point edited each curve to the corresponding profile curve. I split each profile curve at the intersecting cross section curve. (each cross section curve was now 4 pieces and each profile curve was 9 pieces). Using surface from 4 edges (EdgeSrf) I made surfaces in each section. Make sure if you are given the option of selecting an adjacent surface or the original curve, you choose the surface. Complete 1 side then mirror to opposite side. Turn on Zebra and use MatchSrf and MergeSrf as needed to line up surfaces. Join all surfaces,