How to make objects follow an elevated curve yet stand straight? For a project I need to model a railing that follows a spiral staircase. I wanted to use a curve for this, but the poles always stand perpendicular to the curve. I want them to stand straight. (I used a random curve for the tests below.)

I had found a promising workaround using &quot;instancing&quot; (see: https://blenderartists.org/t/how-to-use-array-modifer-curve-to-create-landscape-and-fence/1202336). However, this seems to only work for perfectly symmetrical objects like round pillars because it doesn't seem to rotate the objects at all, making them all face the same way. I have to use a base model that requires alignment with the path in the Z-axis. (I realise I'm better off doing the handrail seperately)

Any help will be sincerely appreciated. If anyone knows of any solutions or addons please let me know, because the lack of options in Blender's array modifier is growing more and more frustrating..
Vanilla Blender can do it perfectly fine!
I found a bug which we can abuse to get the wanted effect ;)
The setup is incredible simple as well. Just make your curve with your array and curve modifier like normal. Then it obviously is not looking like what we would want, but then notice what happens if you scale the curve object in object mode.
To get the wanted effect, just scale the curve in object mode along the z axis to 100 or 1000 of its height. Then go into edit mode and reduce the height by scaling with 0.01/0.001 respectively. This is the result:

EDIT:
In my first test Tilt needed to always be 0.0, but further testing showed, you sometimes need sligthly different Tilt values, but I'm not sure why. That will solve your deformation issue though.
If you only use flat bezier handles (scaled to 0 on the z axis) a tilt of 0.0 everywhere is perfectly fine.