Wall Plugin for SketchUp

[Medeek Engineering]

I've been working on close stringers for curved stair cases.  The circular variety is pretty much figured out but the elliptical variety still needs an instantaneous adjustment to the stringer depth since the pitch angle of the stairs (slope) is constantly changing.  The geometry of a 0.9 eccentric ellipse shows off this distortion quite well.  I will hit it again tomorrow and see if I can't figure out a more accurate algorithm for these stringers.  Sometimes I enjoy a good challenge, but this one has certainly had me scratching my head a few times already.

[Medeek Engineering]

Version 4.6.0 - 06.03.2026
- Added a curved "closed" stair option into the stair module.
- Enabled closed stringers for curved (elliptical and circular) stairs.
- Added a separate layer for stair stringers.

[Medeek Engineering]

[Medeek Engineering]

After mucking around with the follow me API call and a few other algorithms I decided to strike out on my own yesterday, and with a little help from ChatGPT and quite a few iterations I was able to finally generate the closed helical stringers. Using the same principle and by rotating the profile I am now able to generate a similar mesh for the handrails. These are high poly but it does look great and we now have eliminated the twisting issue that I had never resolved using other methods. So a major step forward.

[Medeek Engineering]

Medeek Wall:  Version 4.6.0b - 06.06.2026
- Added handrails to curved stairs.
- Fixed a bug with labels for railing labels with metric templates.

[Medeek Engineering]

Version 4.6.1 - 06.06.2026
- Added tread covers, carpet and stair runners for all curved stair assemblies.
- Enabled a "code" clearance envelope for curved (elliptical and circular) stairs.

[Medeek Engineering]

Balusters on curved staircases is a bit challenging, I'm not going to lie.  My algorithm(s) are mostly working, and I think, as I suggested in my previous postings, I will need to add in some additional (curved stair specific) parameters.  At this point I really hate to add more parameters to these already substantially bloated menus.  Too many settings and options tend to overwhelm the casual or new user, but at the same time we need enough controls or knobs to fully adjust these assemblies, its a bit of a trade off I guess.  As the Japanese say "Shikata ga nai" (仕方がない).

This screenshot is of a "circular" curved staircase with 1/2" square balusters and baluster shoes.  As you can see the baluster spacing is not quite right for either side (inner and outer handrails).  To get exactly 2, 3 or 4 balusters per tread one will need to carefully and probably iteratively adjust the spacing.  Since these arc lengths won't be nice even numbers the exact spacing number will be some fractional value.  I've got some ideas on this to make things a bit easier for the user to compute these exact spacings but I need to experiment with it further.

Its funny how when I start down one of these rabbit holes I don't usually don't know the full solution to the problem or even fully understand the problem itself.  But as I slowly unravel and work my way through one of these problems it ultimately becomes clear and then along the way I seem to always find better ways to address the problems that I encounter. 

[Medeek Engineering]

Version 4.6.2 - 06.10.2026
- Added balusters and baluster shoes for all curved stair assemblies.
- Added separate baluster spacing, offsets and quantities for inner and outer handrails of curved stair assemblies.





With circular stairs it is possible to carefully control the spacing of the balusters so that a specific number of balusters lands on each tread (two on the inner and three on the outer).  However with elliptical stairs the tread arc length may vary significantly so this may or may not be as controllable.  I may need to come up with a different way to space balusters on elliptical stairs. 

Note that in the second screenshot where the balusters are attached to the closed stringer this is not an issue.

Each side can be adjusted separately with the addition of the six new parameters within the Curved Stair Options sub-menu.  This level of granularity is required for curved stairs at the expense of making the menus a bit longer.

[Medeek Engineering]

I've been also thinking about the framing that goes under these stairs and it seems to me that the methods are as varied as there are carpenters. I could provide a basic curved wall framing as shown in the screenshots below but I don't know how much use this would be to anyone as they will probably frame it differently, thoughts?

[Medeek Engineering]

Version 4.6.3 - 06.14.2026
- Enabled open treads for curved stair assemblies.
- Enabled handrail fittings for curved stair assemblies.
- Added six additional parameters into the curved stair sub-menu for handrail extensions and upper fitting rail drops.
- Enabled handrail posts for curved stair assemblies.
- Enabled OTP, CUT, and VERTICAL (PTP) handrail options.
- Added a vertical offset parameter for top posts.

[Medeek Engineering]

Version 4.6.4 - 06.15.2026
- Added a "deck" option to the railing module.

Note that when Railing Type is set to "Deck" there will typically be a cap rail along with an upper and lower rail. The upper and lower rail provide the support for the balusters or pickets.

I will probably need to enable an option to disable or turn off the cap rail.

 

[Medeek Engineering]

Version 4.6.5 - 06.18.2026
- Added a "GLASS" baluster option for curved stair assemblies (circular and elliptical).

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Version 4.6.5b - 06.19.2026

- Added a "CABLE" baluster option for curved stair assemblies (circular and elliptical).

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Turns out there are many possible solutions to the problem when you go from a single arc to a Hermite biarc solution. Of course not all these solutions are useful, especially where they intersect or collide with other segments of the polyline. Quite the education on this topic between Wikipedia and ChatGPT yesterday. Here as some solutions to the biarc and single arc problem:

[Medeek Engineering]

Version 4.6.6 - 06.23.2026
- Added a Curved Segment option/tool for railing assemblies.
- Added a Spline Railing tool into the Stair Toolbar.
- Spline Railings enabled using a Centripetal Catmull-Rom spline algorithm with user selected start and end tangency points.

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https://youtu.be/Tk7-Nb7JA28

[Medeek Engineering]

As I've stated in the recent tutorial the regen time of this spline railings can suffer because of the large poly handrails and/or shoerails.  In the next update I will be introducing and option where the user can toggle a "split" option for both the handrail and shoerail.  This will split those two curved solids into separate segments (at the intermediate posts).  For larger spline railing assemblies my internal testing has shown an almost 100% performance (draw, edit, regen).

These two parameters will be found in the intermediate post sub-menu, see image below:

[Medeek Engineering]

Medeek Wall:  Version 4.6.7 - 06.25.2026
- Added a "GLASS" baluster option for curved and straight rail assemblies.
- Added a "CABLE" baluster option for curved and straight rail assemblies.

[Medeek Engineering]

Version 4.6.7b - 06.26.2026
- Enabled deck railing for spline railing assemblies.
- Added a "GLASS" baluster option for spline railing assemblies.
- Added a "CABLE" baluster option for spline railing assemblies.

[Medeek Engineering]

Tutorial 91: Curved Stairs II - (17:37 min.)

[Medeek Engineering]

The custom wall "draw" tool is going to be a little bit different from the existing wall tools.  Currently I have it so that can select a face (grouped or ungrouped).  The face has to be vertical, in more precise terms this means the face normal vector must be perpendicular to the Z axis.  Also note that as you hover over the face the nearest vertex is highlighted with the light green circle:



This indicates where the "origin" or start point of the wall will be drawn from.  Once you select the face, the tool then goes to phase 2, which allows you to project along the face in one of two directions.  This will determine which side is the interior or exterior of the wall:



The thick blue line indicates the ray or vector that is being used to determine which way the wall is facing, also the 3D wireframe indicates the wall's general envelope or geometry.