Sweep1 surface creation and capping - issue with edges and cap constraint

Hello. I am trying to get a clean surface with sweep1 (attached a projection line with profiles oriented along the curve and following a plane on hte bottom).

However the surface generated is consistently of low quality on the upper corner. The isocurves also do not look good, even when rebuilding the sweep1 to 0.01mm. What would be the solution to get a cleaner surface here?

Next, when the surface is generated, the surface needs to be capped following the capping curve drawn in the front view and departing from the last profile of the sweep1. The front surface needs to follow the indicated plane.
What is the best solution to obtain such geometry? I have tried multiple commands but failed each time.

Sweep1 and Capping.3dm (2.1 MB)

Sweep1 with “Do not change sections” and the seam point adjusted to be consistent for all sections"

The tight radius will be kinked because the radius of the rail is less than the distance from rail the the section. That is how geometry works; not a particular command. Solution is to modify the shape of the rail so that the minimum radius is larger, or add a smaller section at the tightest point on the rail.

You may want to move the capping question to a separate topic.

Sweep1 and Capping DC01.3dm (3.3 MB)

dear @tc11

I would recommend another setting for the curves:
make sure the rail is well designed, check with _curvaturegraph
having the rail in the inner radius - you will not get a problem that the minimum radius is not compatible with the size of the shape/cross curves

use (sharp corner-) polylines as shapes / cross.

with this setting, sweep1 will be quite simple.
_filletEdge afterwards.

Sweep1_and_Capping_02_tp.3dm (881.2 KB)

regarding capping - you should provide more info about your design intention / or the constraints that have to be followed. Maybe a hand-drawn sketch ?

kind regards -tom


Dear @Tom_P ,

Amazing solution, thank you for the insight and clear process!
I think this will work for the main part, and the curvature command is certainly helping.

For the cap, i have done a trial with your profile + added pictures to give an idea. Is this helpful enough to give an idea how to finish it? Note that the edge use is a consistent thickness but this could vary. I suppose a sweep 1 with multiple profile lengths would then work?

Really appreciate your help.



Sweep1_and_Capping_02_tp.3dm (2.3 MB)

Hello- my guess is you want something more like this - even though it is still very hard-edged -

But I think there is more you can do in the initial setup to make this all ‘softer’ and cleaner.


@davidcockey Thank you for yuour answer. I tried selecting different points in the profiles to get them to align like yours, but I am unable to get the same result.

Can you please advise which points you selected to get the cleaner result? Thank you!


@pascal Yes indeed, having it cleaner like that would be more interesting. How did you obtain this result? What would you change upfront to help with the surface creation?

Thank you.

It depends on the order you select the sections. Look carefully and move the one seam point which is out of place.

Hello - I think I would go about this a little differently - I cannot tell if the back face of it is meant to be planar or not… looks like not in your model? In the images in your file it looks to me like the bend in the J is quite arc-like, is that correct?


@pascal The front face is supposed to follow the projected J curve exactly.

The backface should not be planar and side edges though should have no flat surface all along the profile.
→ A radius cannot be less than 3mm + “flat” means without any curved, high or hollow parts having a radius smaller than 2 m.

The final shape should look something in between these two:

ok it s a hockey stick.:grinning:

locks like there is some theory about the “bow”.
my guess is, that the backside is only curved in one direction (extrusion)

some better pictures from Adidas Chaos Fury Kromaskin

what do you need the final data for ?
(rendering, 3d-printing, mock-up, production … ?)

if this is more a design-state of project, it might be easier to do the form-finding with SubD - especially the transitions to the handle and the transitions at the final cap / head.

kind regards -tom

It may be better to start without the fillets, model the surfaces, and then add the fillets as the last step.

Yes indeed, a hockey stick :slight_smile:
The bow theoy explains the projected curve with a local extreme at 0,25,200; and the stick height the end of the curve (36.5 to 38. inch, was not included in the files).

The final data is needed for 3D printing and possible mould development. Would SubD still make sense in that case? The main idea was to control the final parameters in order to easily iterate between different parts.

I agree having seen the different steps used until now :wink:

my guess:
the front / “technical” side / the Bow / the side you hit the ball will be more controlled / precise with nurbs.

The “design” side and your cap-problem will be easier / faster to model with SubD especially if you want different iterations.

you can still convert the design-Side to nurbs, and add a precise technical side, and do a _blendSrf at the corner.

fast and simple SubD approach for form-finding:

Hello- I would make that ‘back’ surface first, as a simple clean oversized thing to be trimmed later, and base the construction of the rest on that - for example, making good clean ‘j-shaped’ curves and projecting them, possibly with Loose=Yes, depending on how you want to use them.

Like so -


@Tom_P Thank you for the tip. I have been looking at the technique wiht the front part in NURBS as you mentioned. I arrive at a nice closed surface, especially when using filleted profiles from the round handle to the sharp edge profiles. For the lower part, using the sharp radius curve with sharp edged profiles works out. However, when starting to filletedge, the trouble starts along the capping area. Even with reconstruction the surface or using pipe, I always run into trouble when analysing with “show edges”. The full stick parts shows the geometry before FilletEdge.

What are the exact commands to run to have the edge in SubD? Would it allow to continue this crease we have at the backside?


@pascal I checked out the idea of construction the surface in multiple parts or reducing the volume from an oversized object. Once you have the nice J, do you generate the surface with patch or would you recommend another command? (in Blocks/Patch Front you can see the surface generated with your technique for the front).

However I am not really sure on how to build the back surfaces. Having an ultimate edge of 10mm (dark blue line, all in the blocks/backside layer
Issues.3dm (3.8 MB)
), I am trying to build a surface that would link the backside quads to the ultimate edge and then project the lines on the back face on it (light blue), but I am not sure how to extend this surface to then use it for the projection and obtaining more curves (when i extend, i get away from the key points of the geometry). Do you have a tip to do this?


Thank you Tom and Pascal, I really appreciate your input and help!

Well, I don’t know enough about the design to really say but in your file I see this curve in Right:


I draw a clean new curve in right that is longer than but matches the curve:

I then extrude that curve to make a clean simple oversized surface:

I say that is the back surface of the stick - I can then start to build my J on that surface and trim it when I am done. I think you can do about the same thing for the ‘front’ surface, at least that is what I did here :