Influence Slider for sweep 1 and sweep 2

Would it be possible to add an influence slider to sweep 1 & 2 similar to the Blend Surface command?

Hi Michael - BlendSrf has no input curves across the blend, it makes up its own, and the sliders influence the shape - the point structure is known. The sweep commands do have input curves across the sweep - what would you expect the sliders to do?


How much influence the profile shape has from one side to the next. This is an example, from the Top View the rails would stay consistent but from the side view I could adjust the influence of the profiles.

I see - sort of - the action is along, rather than across in your scenario. But you’d need sliders per-profile, correct? Does the slider affect the ‘weight’ of the profile in both directions or would there be two separate setting, for shape curves that are not on the ends?


So I was discussing this with my co-worker, I’ll add him to into the mix so we can clarify how we envisioned this working for a sweep with multiple profiles. @Me_Dave My thought is that you would add control point handles to each individual profile (on both sides if necessary) similar to the blend surface command.

Going to meeting now. Have a few thoughts to offer. Will upload descriptions/definitions with images when I return.

Edit: Just realized this requires more detail. The information below is relating to the transition of cross section from one profile to the next which would adjust the surface the way Michael is describing, I think.

I was thinking of 3 options for this functionality.

  1. Scale slider (0-1) that would apply equally relative to the position of each profile in a list of inputs ( I’m guessing they would automatically be sorted and not reflected by order of actual selection by user).

  2. Would use a secondary interface with a curve on a graph to define a linear or non linear (default linear, if user clicks in graph additional point is added to allow creation of non linear curve) progression for each profile. All profiles would reference a single 0-1 scale slider relative to the relation with the graph.
    Left point and right point would be allowed to be moved to define min and max values to be used by scale.

  3. This option could act as a manual interface where the user has the option to define the transition between each profile in the list. This could operate similar to “Add Shapes” within the “Blend Surface” tool. The user might use handles between each profile similar to tangent handles for blends.

Side Note: If this functionality is viable it would also be useful to stack options 1 or 2 with option 3. Majority of profile transitions would be defined with option 1 or 2, then any exceptions could be defined individually with option 3.

Hope this helps. happy to provide additional details/context if needed.

Hm, yeah, I think it gets complicated…,. but if I understand the proposed control, I’d expect an S shaped Bezier always, it is never a linear transition - hard corners that are not in the rail(s).

But this a) in BlendSrf this acts across and not ‘along’ the sweep (BlendSrf is a Sweep command under the hood) and b) depends upon the command being in charge of creating and placing the shape curves; in the actual sweep commands this is not the case. I’m having trouble seeing how this could apply, but I may need a coffee.

I think I see more or less what you’re after here but the UI is not obvious to me. The curve proposed by @Me_Dave makes some sense to me if it is, as it were, horizontal,

(for Sweep2 here)

maybe that is what you are describing?


Unfortunately, complicating things is something I’m known for. Lol
Everything I was referencing was in relation to the transition of the cross section for the sweep. The bezier curve would define how the cross section changes as the sweep is created. If sweeping a square to a circle this slider would dictate how far along the sweep the square is maintained before transitioning into a circle. I can complicate further if needed.

1 Like

We may write a grasshopper algorithm in an attempt to emulate the behavior.