"Drift" when using Power Duplicate on large number of items

[bobstro]

I'm new to AD and have only limited experience with vector graphics programs in general, so please bear with me. I'm trying to use AD to create a watch face. I have done this using GIMP in the past with few problems, but am hitting some frustrating issues with AD.

 

I want to have the following markers displayed along the outer edge of the watch face:

• sub-minute markers 5 per minute. Rotation = 1.2 degrees.
• Minute markers = 6 degrees
• Hour markers = 30 degrees

I create my 1st marker as a vertical line at the 12 o'clock position, then cmd-J to duplicate, move the rotation center to guides at the vertical and horizontal center of the face, rotate it (painfully) by zooming in and dragging to the desired 1.2 degree rotation, then use cmd-J to make duplicates. I've been able to use Power Duplicate to create small numbers of duplicates, but find it "drifts" when trying to do larger numbers. 

• I have tried clicking the outside center, inside center and center buttons in the transform box with little success.
• I have tried entering 1.200000 as the R value in the Transform box.

By the time I generate enough sub-minute markers to get to the 90 degree position (75 duplications), I see 2 common problems:

• The rotation value has drifted by +.3 degrees. At 90 degrees, the final marker is at 90.3 or worse.
• The rotation center drifts, resulting in a spiral effect.

This "drift" is so bad that my hour and minute markers don't even align properly. This is all compounded by having to rotate using the mouse, as entering values directly into the Transform R box changes the rotation center.

 

The only workaround I've found is carefully creating a small number of markers, duplicating these as a group and rotating those. I'm finding this much slower than I expected.

 

In GIMP, I'd create the 1st marker, duplicate and rotate 5 markers, merge those layers, duplicate and rotate 6 degrees for the next minute and successively merge, duplicate and rotate until I could produce a dial in a few minutes.

 

I have also purchased Affinity Photo, but don't see a better solution there, and I'd prefer to stick to vectors. I don't think there's anything much simpler than a watch face, yet I'm finding this very difficult to achieve. Am I missing a fundamental trick?

 

 

 

 

[Dale]

There is an easier way to make the shape that bypasses any duplication and rotation issues - using a (or more than one) Cog shape.

 

Have a go at using the Node tool on the attached file and modify the shape parameters in the Context toolbar to achieve the face you're after. This doesn't mean that Power Duplicate is or isn't working right, that'll still need investigating.

360 cog shape.afdesign

[A_B_C]

Hi bobstro,

 

and welcome here …  :)

 

No wonder that you are experiencing this kind of drift. As you probably saw, you cannot enter rotation values numerically with respect to a shape that has a custom rotation centre. And the value display provided next to the on-canvas rotation handle is too coarse to inform you correctly about the actual rotation values. In order to use create precise rotations around a centre, you will have to use a workaround:

• Create a duplicate of your stroke mirrored at the midpoint of your clock face.
• Group both strokes, duplicate the group, set the rotation midpoint to “Centre” on the Transform Panel, and enter the intended rotation degree. 
• Power duplicate.

By doing so, you won’t get the drift you experienced by creating your rotation manually. Other than that, I would also suggest to follow Dale’s method.

 

Hope that helps …  :)

Alex

[bobstro]

Thanks Dale & A_B_C. Both look promising. 

 

I'd looked at the cog but had no idea I could set one with 300 teeth! I'm understanding I can anchor to shapes, so that may be very convenient.

 

A_B_C so a shape or group of shapes that spans the actual center without relocating the rotation point is the key then? 

 

I'll try these out this evening. Thanks!

[JimmyJack]

I'd looked at the cog but had no idea I could set one with 300 teeth!

 

Type the desired number in the input box (slider stops at 48)  :) .

[A_B_C]

A_B_C so a shape or group of shapes that spans the actual center without relocating the rotation point is the key then?

 

Yes, that was my suggestion. But when using the Transform Panel, don’t forget to change the reference point of your transformation to the centre of the selected group, before you enter a rotation value. The largest of the nine little squares indicates the reference point (see below).

[bobstro]

Your tips worked perfectly. The cog is handy for quickly placing things visually. The trick of grouping objects so that the center point is located on the hub is the key.

 

Here's what worked:

1. Create the 1st marker as a vertical line in the 12 o'clock position.
2. Duplicate it with Cmd-J
3. Rotate the selected copy holding the shift key to restrict it to 15 degree increments into the 9 o'clock position
4. Power duplicate the copy 2 times to create the 6 and 3 o'clock markers, giving me a set of 4 perfectly aligned markers
5. Select all 4 and type in 1.2 (or 6 or 30) in the R box on the Transform menu
6. Power duplicate like a madman with Cmd-J

I turned off the original 4 markers and was delighted to see the final set of duplicates come to position at exactly the 0, 90, 180 and 270 degree positions. It's not intuitive, but it works quite well now that I know the trick.

 

I think the cog will simplify another challenge I had using GIMP in aligning elements on the face. I'd create a circular guide line, some radial lines and try to align on that. Using the cog, I'm hoping I can easily snap to geometry much more easily.

 

Thanks A_B_C & Dale. I'm really enjoying AD and this has helped get past a real stopping point.

[JackofDiamonds]

For the sake of covering everything, you can also force rotation in 15 degree increments by holding shift as you drag the rotation handle. If you cover all of the sub-15 increments and use this rotation with duplication, it will be spot on.

[R C-R]

There have been feature requests for the Transform panel to work with custom rotation centers, but I do not know if this is on the current roadmap or if or when it will be implemented.

[bobstro]

Just a quick follow-up. I was able to knock out 2 variations yesterday, and now that I have the basics down, the entire process is much faster.

 

The cog is ideal for adjusting placement of elements, and the selection of objects 180 degrees apart has taken care of my rotation woes. Thank you all very much!