Help using Curve in Blender

[Fenix Eldritch]

I'm trying to model a building similar to this: [link]

So far so good, but I am having difficulty with the rounded corner on the left side. Due to the windows on that part, I modeled the section as a straight, un-curved segment and intend to use the curve modifier to gracefully bend it 90 degrees. I've added enough vertical subdivisions to support a reasonable curve.

However, I am having a hard time being "exact" when applying the modifier. That is to say, I've already modeled the front part of the building and want to align the curved part such that the near edge snaps to the front wall, and the "far" edge is perfectly 90 degrees from the other edge - so I may extrude that out to start working on the side wall.

So far, every tutorial I've looked at seems to treat the curve modifier as an inexact process. Am I going about this the wrong way?

[Drongle McMahon]

The best thing would have been to start with a cylinder, then delete three quarters of it. If it was a straight corner edge, you could use bevel to round it, but that doesn't work with undercuts like those you have. So here is a simple example using Spin of which a variation should work for you.

1. Here is the starting point.

2. Make some loop cuts where you need the rounding, and remove the corner vertices. Snap the cursor to the centre of the circular curves (anywhere on Z axis).

3. Select the perimeter you need to rotate. If the vertices sren't lined up in a plane, use SY0 to align them with the central vertex, having lined up the other cut edge using SX0 first. (You need the pivot center set to cursor for these to work.)

4. Go into top view and click the spin button in the tool shelf. Here it was set to eight segments and 90 degrees, duplication off.

5. And that's it.

[Fenix Eldritch]

Much thanks, Drongle! However... I'm afraid I'm still doing something wrong; the resulting spin is slightly squished. The radius is fine along the y axis, but is almost looks like it's about half on the x axis.

I set the pivot point to 3D cursor and the cursor itself at the "center" of what will be the the spun object. Testing it out by setting the degrees to 360 confirms that everything is "centered as it should be, but it doesn't expand the correct distance on the x axis...

[Aquila Kytori]

Hi:)

I was trying to get the same deformed effect as you and I found that if I went into Object mode and Scaled my edge along the Y axis and  then returned to edit mode and did the 90° spin mine looked very much like yours

So what you have to do is go back to Object mode and Apply Scale :   Object Mode > Ctrl A > Apply Scale.

Then return to edit mode to do the spin .

[Fenix Eldritch]

Doh! That was it. I didn't even realize I had any scale on the object. After applying it, the spin worked like a charm. Thanks both!

[Drongle McMahon]

Yes. Aquila is right. I'll try and explain.

The locations of vertices you end up with is a combination of the edit-mode geometry and the object mode transformations (rotate, scale, translate). But the spin (and many other things) work just on the edit-mode geometry. So if you have a scaling along an axis in object mode, then it makes a circle in the edit-mode geometry, but that still gets squashed (or stretched) by the object mode transformation. This problem comes up a lot, and it is probably best to avoid object mode editing as far as you can. If you do use it, remember to keep applying the transformations, which removes them from object mode and applies them to the geometry in edit mode instead. You often need to do that before exporting as well.