Power duplicate around circle not precise. What am I missing?

[Jaroslav]

Hi guys.

I was recently working for one of my clients and we accidentally found out that power duplicate, or simply when I try to rotate objects or some curve around the circle, than the duplicated/rotated objects always miss the attachment points on the circle. I documented it in the screen recording down below. I am putting it in this Bug report thread because I couldn't find any solution for this. I even tried 360/X rotation instead of exact numbers, but it didn't help. 

Is there something I am missing here? I will be very glad for any help. 

Thanks.

[SPaceBar]

Hi @Jaroslav Could you upload the document here please? I'd like to try it using the same measurements as you.

[Jaroslav]

Hi, of course. Here is the file:

file.afdesign

[Dazmondo77]

I've just tested using various shapes and I'm getting the same problem ---- wow that is really bad

[walt.farrell]

I wonder if this is related to the known issue that the Affinity applications don't create mathematically exact circles?

[Jaroslav]

2 minutes ago, walt.farrell said:

I wonder if this is related to the known issue that the Affinity applications don't create mathematically exact circles?

I am afraid that is the case. No matter how hard I try, I just can't rotate it precisely around the circle. I tried to draw a line from the middle of the circle to the edge of it, and as I am rotating it, it just doesn't fit. 

I would have never though to check if the circle is a circle. I guess I will need my girlfriend to draw me circles in her Illustrator haha. 

Anyways that is very messed up, if it really is the case. I hope there is a solution out of this because I will need to buy Illustrator just to finish my work. 

[Jaroslav]

Yes I just checked it. The circle is a problem. I tried to rotate a two circles of exactly the same size, and when zooming closely they just don't fit to each other. The circle seems to be fine at 90 degree angles, the problem is somewhere between those. 

Well, so the circle is not a circle. Seems like it.

[MEB]

Hi @Jaroslav,
Welcome to affinity Forums
Thanks for your report/feedback.
Currently we do not render (precise) geometric circles as you already find out. They're drawn as an approximation using Bezier curves. Unless you zoom in really really close this shouldn't be noticeable however devs are aware of the issue and looking into it. It might be improved in future versions.

[tomgreen]

On 8/26/2021 at 7:03 PM, MEB said:

Hi @Jaroslav,
Welcome to affinity Forums
Thanks for your report/feedback.
Currently we do not render (precise) geometric circles as you already find out. They're drawn as an approximation using Bezier curves. Unless you zoom in really really close this shouldn't be noticeable however devs are aware of the issue and looking into it. It might be improved in future versions.

Hi I've just run in to a similar problem when using power duplicate to rotate a line which is the exact diameter of a circle. I've noticed in some places the line doesn't quite touch the circle boundary and in others it extends beyond the circle. Are you saying AD can't actually produce a mathematically accurate circle and so there is no solution to this issue?

[NotMyFault]

On 8/26/2021 at 7:22 PM, Jaroslav said:

Yes I just checked it. The circle is a problem. I tried to rotate a two circles of exactly the same size, and when zooming closely they just don't fit to each other. The circle seems to be fine at 90 degree angles, the problem is somewhere between those. 

Well, so the circle is not a circle. Seems like it.

I did test rotating on iPad and couldn’t reproduce it there. So definitely not related to “imperfect” circles. Seems to be an MacOS specific bug.

The deviation from perfect circle is <1% of radius, visible but far too small to explain the power duplicate issue.

[NotMyFault]

4 hours ago, tomgreen said:

Hi I've just run in to a similar problem when using power duplicate to rotate a line which is the exact diameter of a circle. I've noticed in some places the line doesn't quite touch the circle boundary and in others it extends beyond the circle. Are you saying AD can't actually produce a mathematically accurate circle and so there is no solution to this issue?

There are actually rounding issues when using power duplicate. A long time ago i reported a similar sounding issue, see https://forum.affinity.serif.com/index.php?/topic/141872-documentclip-canvas-issue/&tab=comments#comment-784794

Affinity can correctly deal with circles within given constraints, especially rounding issues can aggregate quite badly. There are different ways to create circles. If required just add more nodes to increase accuracy, or use segments. 
To get an perfect circle as reference (pixel layer), use Photo, quadratic canvas size, straight lines, and rectangular to polar filter. Uses this to add nodes where the “imperfect” circles deviates too much.

The example file of 512 px radius shows that the error is below 1px.

In my view the “circle is not perfect” is exaggerated, as the error hides almost complete within anti-aliased edge pixels. Only if you deactivate anti-aliasing, and use 1-2px thin curves, the error gets detectable  when you are looking hard. And it is maximum 1px misplaced, no more. So relevant only for small radius values.

 

perfect circle.afphoto

Edited September 27, 2021 by NotMyFault
Added file

[tomgreen]

On 9/27/2021 at 11:25 PM, NotMyFault said:

In my view the “circle is not perfect” is exaggerated, as the error hides almost complete within anti-aliased edge pixels. Only if you deactivate anti-aliasing, and use 1-2px thin curves, the error gets detectable  when you are looking hard. And it is maximum 1px misplaced, no more. So relevant only for small radius values.

Hi @NotMyFault, thank your response. I agree that the imperfection is not really such an issue when working with anti-aliased images and smaller artworks. In my case I use vector software to create large scale multi layered wooden artworks that are cut using a laser machine, so at a size of say 80cm the imperfection in a circle is noticeable. I'd really like to use AD for an entire project but these inaccuracies along with the lack of a shape builder tool and the poor implementation of the Divide boolean operation when creating complex shapes means it has been impossible.

Thanks again.

Tom.

[NotMyFault]

2 minutes ago, tomgreen said:

In my case I use vector software to create large scale multi layered wooden artworks that are cut using a laser machine, so at a size of say 80cm the imperfection in a circle is noticeable.

That is a use case where Affinity apps got stretched beyond their expressed capabilities and usefulness.

For serious work in that area I would always recommend a real CAD app, and not a “tool for creatives”.

The forum is full of similar reports about several issues and missing functionality with output for laser cutters, and CAD like construction design.

Honest question to you:

If the circle imperfections are the only issue of this kind, could one of the theoretical workarounds I suggested be practical/ helpful for you?

• Instead of using an ellipse / circle shape, which is based on Bézier curves with only 4 nodes, create your own circle asset based on a curve with a higher number of nodes (8, 16, 32, …) to achieve higher accuracy 
• can you express the required level of accuracy for you work numerically?

 

[tomgreen]

11 minutes ago, NotMyFault said:

Instead of using an ellipse / circle shape, which is based on Bézier curves with only 4 nodes, create your own circle asset based on a curve with a higher number of nodes (8, 16, 32, …) to achieve higher accuracy 

Possibly the best option yes. My background is in Graphic Design and Illustration, 20+ years, so I'm more used to creative software than CAD programmes. My artworks are also output as prints, posters etc so I still need the graphic capabilities. For now I'll stick to my other software and maybe come back to Affinity if they improve the boolean tools and add a shape builder. I've used AD since the beta programme and was very hopeful at first but sadly in all these years it's not been possible to complete an entire project with it.

[Jaroslav]

1 hour ago, tomgreen said:

Possibly the best option yes. My background is in Graphic Design and Illustration, 20+ years, so I'm more used to creative software than CAD programmes. My artworks are also output as prints, posters etc so I still need the graphic capabilities. For now I'll stick to my other software and maybe come back to Affinity if they improve the boolean tools and add a shape builder. I've used AD since the beta programme and was very hopeful at first but sadly in all these years it's not been possible to complete an entire project with it.

Same here. But I am trying. Although it's sometimes harder way to do things. But I'm still waiting for the day I will not be forced to have other software installed "in case" I need it for kinda basic tasks like this one. Yes there is a way to do things differently, like it was mentioned here, but still the struggle of knowing that when you open different software, and it will save you plenty of time when doing your work, is just simply bothering. But still. I like to be a pioneer so, I am forcing myself to do all those "impossible" tasks in AD, but still keeping Ai in the back pocket and feeling like split personality sometimes :D 

Good luck guys with future updates. I really wish Affinity becomes full alternative for (in my case) Adobe apps, or even more than just a "alternative". 

[NotMyFault]

Please find my "perfect circle shape" below.

It is contained in a 256.000x256.000 file (but small as pure vector).

There are 2 "perfect circles" atop each other.

When you use move tool to rotate the "stroke only", you can see that it preserves it perfect circle shape independent from rotation.

Hope that is all you need. Use it as a replacement for regular ellipse (imperfect circle).

• The screenshots shows the edge at 45°. The dark grey and light grey lines are created by a star shapes. This perfectly keeps all lines at same length.
• So the light grey line is your reference for 128.000px length. The dark grey servers as reference for the 45° angle (in case the the circle does not keep its radius.
• Compare how a ellipse of same size behaves when rotating. The error is about 1/5.000 of its diameter (25 pixel deviation when rotated 30°)

 

 

Image 2: Measurement of deviation of ellipse tool when rotated 30°

 

 

 

 

 

perfect circle curve.afdesign

Edited September 29, 2021 by NotMyFault

[Jaroslav]

19 hours ago, NotMyFault said:

Please find my "perfect circle shape" below.

It is contained in a 256.000x256.000 file (but small as pure vector).

There are 2 "perfect circles" atop each other.

When you use move tool to rotate the "stroke only", you can see that it preserves it perfect circle shape independent from rotation.

Hope that is all you need. Use it as a replacement for regular ellipse (imperfect circle).

• The screenshots shows the edge at 45°. The dark grey and light grey lines are created by a star shapes. This perfectly keeps all lines at same length.
• So the light grey line is your reference for 128.000px length. The dark grey servers as reference for the 45° angle (in case the the circle does not keep its radius.
• Compare how a ellipse of same size behaves when rotating. The error is about 1/5.000 of its diameter (25 pixel deviation when rotated 30°)

 

 

Image 2: Measurement of deviation of ellipse tool when rotated 30°

 

 

 

 

 

perfect circle curve.afdesign

Hi guys,

so as I'm working on a project where I again need "perfect" circle  I tried to use the "Perfect circle" given here in this thread. And well. I have really no idea if I am doing something wrong here, but those circles somehow don't work with Affinity I guess :DD 

Look.

So there is no practical use for me here, unless I would need "just a perfectcircle"... 

[NotMyFault]

Please find the perfect donut below.

I hope this shape acts correctly now.

 

Never the less, when using geometric functions you should always check the number of nodes of the resulting shape. For a "perfect" circle there should be a node for every 30°. As long as the center point is preserved, and you know the intended radius, you can always cross-check by adding a line (with pen tool) between center point. If you spot too much deviation, just add an supporting node at the crossing.

 

perfect donut.afdesign

[NotMyFault]

Now giving away my secret sauce for free, to allow you to create more specialized shapes if required.

• Use any circular shape (donut, etc) and adjust to needs (inner radius etc)
• Add a 12 spoke star. Reduce inner radizs to 0
• Align in size and position perfectly
• Add stroke of e.g. 4 with hard corners in black
• Copy and resize to match inner circle. change stroke color to light gray
• Copy and resize to be slightly larger than out radius
• Activite snapping
• Use node tool to add nodes to circle at the intersection of star and circle. These nodes help to "stabilize" circle radius every 30 degree.

[telemax]

Here's a simpler version. I was able to get fairly accurate results with the Cloud tool, with 12 Bubbles. I checked the result with a star with 12 beams as @NotMyFault advised, as well as with 24 beams, and got a good result. Circle.afdesign

 

[DEMIS]

Hello, I'm currently using the 1.10.5 of Affinity Designer. I've been working on Adobe's since 1996 and as I'm working on a personal huge project and as I've bought the Affinity suite last year I was like, K et's use Designer only for the graphic part. I was so amazed and really loved it until...I needed to create patterns including circles. I also had to use the power duplicate option to copy objects around those shape and it's been a couple days I'm like "What's going on there, I might be stupid for sure". I 've watched several tuts about it and I must say as it's pretty much simple on the paper I knew after some time that there wasn't something wrong with me. With the same shape, the same setting I have shape that rotates in a weird way like we've been able to seen there (like in a slight spiral effect) or the first shape copies at 15° perfectly BUT the second one copies on itself. And If you keep hitting command + J it keeps copying on itself🙄. I just couldn't believe my eyes.
Just a simple question, do we know if the "perfect circles" are really on the debug list for a next update please?
Thank you so much for your help.
I really hope there will be a fix because other thank that I love your products.🤘

[walt.farrell]

3 hours ago, DEMIS said:

BUT the second one copies on itself. And If you keep hitting command + J it keeps copying on itself

You must be very careful with the order of the operations:

1. Cmd+J to duplicate the object.
2. With the duplicate selected, transform it.
3. With the duplicate still selected, transform it again.

Your description sounds like you have deselected the duplicate somewhere before step 3.

[Dangerous]

I had a similar issue. I had a circle and wanted 214 radial lines from the centre but Power Duplicate got it wrong. Try as I might it would not work. I realised that the angle of rotation through the duplication process was the issue as 360/214 = 1.682243. With a bit searching I found in PREFERENCES - USER INTERFACE there are settings for decimal places for unit types DEGREE setting changed to 6 and it worked perfectly. There are other settings you can alter the precision for which may help with other issues you may have.

I don't know if that will help in this issue but it did in my situation.

 

[GarryP]

57 minutes ago, Dangerous said:

DEGREE setting changed to 6 and it worked perfectly

The decimal precision values in “Preferences / User Interface” should only affect the values that the user sees in the UI and should not have any affect on the actual values within the document or how the software works internally.

Can you supply a step-by-step example – a workflow which someone else can follow – showing where this is not true?

[Alfred]

1 hour ago, Dangerous said:

I realised that the angle of rotation through the duplication process was the issue as 360/214 = 1.682243

Did you enter the angle as 360/214 or 1.682243? The former should work correctly, but the latter is slightly imprecise since 360/214 to eight decimal places is 1.69224299.