Import bezier curves from Sketchup for stair outline

[arisleme]

Hello everyone, 

I attempted a multi-step endeavour and don't know at which step it failed:

I wanted to create a fluid stair and since Revit (to my knowledge) doesn't offer bezier curves, I thought I would import the outlines (as dwg) from sketchup and trace them with stair/sketch. Everything worked fine except for the supports and rails which broke at each step.

As far as I understand there are two possible culprits:
A) the dwg format itself doesn't retain the bezier curves as curves, but instead breaks them apart.

B) Revit doesn't recognize bezier curves so that's why it brakes it.

the side curves were 'unbroken' when I exported but when the geometry was imported in Revit only the riser curves (which are arcs) survived. same thing happened when I opened the dwg with autocad.

Does anybody have any idea how I could work around this problem? and most importantly: are the only curves that Revit recognises Arcs/ Circles? I hope not!!!!

[ToanDN]

You better rebuild the curve in Revit using arc sketch tool to reduce the number of segments.  From what I see I guess it can be done with 2 or 3 arcs.

[arisleme]

so... only curves are arcs? in model line- sketch u can use splines, why not in stairs- sketch? grrrr

[ToanDN · Accepted solution]

It's the current limitation of stair and railing tools. You could resort to model in-place stair and adaptive family railing if you must follow splines.

[Kimtaurus]

A bezier curve in Sketchup isn't a real curve either, rather a series of shorter straight lines, similar to how circles are drawn in Sketchup.

Your best option is indeed to redraw the curve using arc-segments. If you don't want the stringer/carriage to be broken up, you could drawn them as a model in place.

[arisleme]

so you guys are telling me that sketchup is better for designing stairs than Revit? I am new to this program but the more I dig into it, the more bauhaus-y it appears to be! No spirals, no parabolas, no hyperbolas, just lines and circles! :((((

anyway, don't want to sound negative. The bottom line is that for the stair supporter to be continuous, the boundaries must be either straight lines or arcs (and elipses) right?

[Kimtaurus]

Spirals = circle segments, so yes you can make this in Revit.

If you want paraboles, beziers etc, use adaptive components.

I suppose the reason this we're not able to use this for construction elements, is because they are nearly impossible to set out on site, whereas lines and circle(segments) are.

[arisleme]

I am starting to think this program is only for designing office buildings 😞

[Kimtaurus]

In the office I work, we use Revit for offices, stadiums, public buildings, housing,... You really can create anything in Revit, you just need to know how. The program has many features and tools, so it takes some time to learn them all. I've been using Revit for 10 years now and I still don't know all the features.

[ToanDN]

It's similar to building construction. There are standard components and there are custom components. Some you can buy off the shelf and the others you need special craftmanship to build.

Revit provides you with model in-place tool and the entire freeform mass/adaptive modeling for a reason.