Rectaglar hole in the side of a cylinder.

Modeling a spiral staircase where the treads revolve around a cylinder. So far I have tried use edge loops, edge crease, split edge and all kinds of combinations of theses. Tried a Boolean to see if the resulting mesh could be reworked. What a mess when subsurfed. The results I achieved so far is pinching in the corners and in general just not a clean hole (notch). Lots of tuts on creating a round hole in curve surface, but a square or rectangle.:no: I do not think an image of the mesh would help. But have a look at the drawing of what I am trying to create, this I hope will clarify the problem. Thanks

Can you avoid the problem? Why not just position the planks going though the cylinder wall and not cut any holes at all?

Yes, I considered this. But that would take away the challenge. In all considered this will be the route I will take. Yet I am looking or searching for knowledge, so taken the easy way out was not the reason of posting this thread. So guess I am asking if anyone has a solution that I may missed. Thanks for your reply kastoria.

Fair enough!

Reread my reply. Wow bad English.

Okay - you need to simplify this a bit.

First, work on one stair only, then you will later duplicate this upwards to complete the set of stairs in a spiral. You’re going to need a calculator for that part because you will need to spin the correct number of degrees to line up with your stair planks.

To make one hole, add circular edgeloops above and below where the plank cuts in. Now, add the edgeloops to each side effectively completing the outline of the “hole”. You can extrude these areas inwards or simply [X] key delete the faces.

You then use an array to duplicate the section you have (short pole with one stair hole) upwards. This will not rotate them. Then, select each and rotate accordingly (Z-axis rotate, punching in degrees to twist). If you SHIFT select all stairs as a group, you can use the same number all the way up without having to recalculate a different “turn” each time.

Maybe I failed to understand the problem. Here is a spiral staircase using a simple array with an empty for offset.


Spiral-staircase-001.blend (230 KB)

Beautiful. Same logic as mine but more efficient. Woodprint; this what you are after?

I tried a couple approaches to this, it doesn’t seem possible to do this at the lowpoly level with a subsurf modifer, it is pretty easy to get some nice results at higher polycounts, I originally started at an 8 sided cylinder which failed, but at 32 and higher the results are nicer, the higher the better.

I’m fairly certain what Woodprint is talking about is, creating the cylinder with the step insert slots modeled in addition to the steps, this will look nicer during render time, even if its not the most efficient approach (just having the steps intersect with the cylinder)

Here is a result that I came up with:

Lancer this is the approach I am using. Except of using an array modifier. Instead I created one short section the pole and tread, then shift D to duplicate that section, then move in the Z axis follow by a rotation of -22.5 degrees such that the verts line up.

Proxe nice and yes I am trying for lower ploy count due the complexity of the scene.What you have done that I did not try was give thickness to the cylinder wall.

This room is very rustic and come render time I would want to see gaps where the treads meet the pole.