# Object Clipping When Rotating

[EC71PZ]

## What I Want & The Problem
I want to create a large circle with smaller circles following the inner-line of the larger circle at differing positions on the inner-line; yet every time I rotate the smaller circles within the larger one they begin to either clip the larger circle (going over its edge) or become pulled away from the edge (going off of the path) at certain points. (Both circles are perfect circles)

## Approach
I've setup ruler guides at the center points on the horizontal and vertical nodes of the larger circle and I snap the center-edge of the smaller circle to the larger circle's right-side node (without clipping) after that I take the smaller circle's "Transform Origin" and place it in the center of the larger circle; then I duplicate the smaller circle and begin rotating them individually around the larger circle by selecting a single small circle and the larger circle and then choosing the rotate handle. Whilst doing this multiple times around the larger circle there begins to be points around the circle where the smaller circles are no longer attached to the edge of the larger circle.

Any help will be appreciated.

Thank you,
EC71PZ

Edited March 11, 2021 by EC71PZ

[loukash]

Please post an example document, or a sketch of what your actual goal is, or something.

[Alfred]

I think the OP is describing a result like this, where the small circles at the top sit neatly on the edge of the large circle but the others slightly overlap it:

[loukash]

58 minutes ago, Alfred said:

the small circles at the top sit neatly on the edge of the large circle but the others slightly overlap it

I see.

I just noticed that this can happen if e.g.:

• Preferences > User Interface > Decimal Places is set to low values
• you have various snapping options turned on
• you are relying on the values that the Transform panel is displaying (and why the heck shouldn't you?!)

… and combinations thereof.

Let's say you place and nicely align the top small ellipse, then you clone it and align it at the bottom as well. Now you have two small ellipses that you duplicate and rotate, the default being rotating around the center of both ellipses, right? Well, after rotating, both new ellipses that are now at, say, 3 and 9 o'clock, might be a few µm or more off.

That's definitely a "WTF moment".

So, even though you may see integer values like 20 mm, 80 mm, etc. in the Transform panel, in reality the accurate position might be a few µm off but you won't know.
Even worse, it seems that sometimes it doesn't even help to type "20" if you want exact position or size of "20 mm".
What helps, though, is typing "20.0000" into the Transform panel just to make sure it overrides any "hidden" decimal values or rounding glitches or whatever it is. The bad news is that you may need to repeat it for every object involved.

Looks like it's a bug, not a feature.

I'll try to reproduce it while recording a video.

[loukash]

3 minutes ago, loukash said:

What helps, though, is typing "20.0000" into the Transform panel just to make sure it overrides any "hidden" decimal values or rounding glitches or whatever it is. The bad news is that you may need to repeat it for every object involved.

In fact, similar annoying glitches also happen in Illustrator (CS5 being the last version I'm working with). I remember reading that it's because internally Illustrator counts in imperial units, and those are rounding errors when a user works in metric units.

[loukash]

15 minutes ago, loukash said:

I'll try to reproduce it

Hm… I can't. Not sure why.
Perhaps I also had snap-to-grid or snap-to-pixels enabled on my first attempt? That can cause some seemingly "correct" snaps being slightly off.

[MEB]

Hi @EC71PZ,
Welcome to Affinity Forums
Currently our circles are not perfect circles but an approximation using Bezier curves, thus at certain points of the curve there may be some minor deviations from the "true" value at high zoom levels. We hope to improve this in future versions using a different way to render the circles.
If you are getting huge gaps or overlaps (check if the zoom level is at a reasonable value) please attach the file for inspection. Thanks.

[loukash]

6 minutes ago, MEB said:

Currently our circles are not perfect circles but an approximation using Bezier curves

Interesting!

6 minutes ago, MEB said:

at certain points of the curve there may be some deviations from the "true" value

A circa 25 mm circle rotated 45° is off by mere 0.0025 mm. That's usually negligible.
So I don't think that's the issue here, if any. As noted above, my own experience might have been caused by "false snapping" in the first place.

[EC71PZ]

7 hours ago, Alfred said:

I think the OP is describing a result like this, where the small circles at the top sit neatly on the edge of the large circle but the others slightly overlap it:

Yes, exactly this, but some overlap and others cease to touch the line.

5 hours ago, MEB said:

Hi @EC71PZ,
Welcome to Affinity Forums
Currently our circles are not perfect circles but an approximation using Bezier curves, thus at certain points of the curve there may be some minor deviations from the "true" value at high zoom levels. We hope to improve this in future versions using a different way to render the circles.
If you are getting huge gaps or overlaps (check if the zoom level is at a reasonable value) please attach the file for inspection. Thanks.

Yeah, it's only at high zoom levels that you can see it, but nonetheless I'd like for the smaller circles to be perfectly aligned along the edge of the larger one (or are you saying they are truly aligned perfectly just not shown that way when zoomed in?). Is there any way that I can manually place each smaller circle along the larger one and have them snap into place on the curve?

Thank you for the replies!
EC71PZ

Edited March 11, 2021 by EC71PZ

[Old Bruce]

Just to be clear, do you want all the smaller circles' circumferences to be tangental with the largest circle's circumference?

[EC71PZ]

9 minutes ago, Old Bruce said:

Just to be clear, do you want all the smaller circles' circumferences to be tangental with the largest circle's circumference?

Haven't a clue what you're asking. To put it in Layman's Terms: I want the edge of the smaller circles' to align with the edge of the larger one--at any point of my choosing.

Thank you,
EC71PZ

[Old Bruce]

6 minutes ago, EC71PZ said:

Haven't a clue what you're asking. To put it in Layman's Terms: I want the edge of the smaller circles' to align with the edge of the larger one--at any point of my choosing.

Thank you,
EC71PZ

I got confused by your two statements in the post preceding my question, so here is a picture

At any point of your choosing could mean... 

[EC71PZ]

7 minutes ago, Old Bruce said:

I got confused by your two statements in the post preceding my question, so here is a picture

At any point of your choosing could mean... 

Okay cool. The first quote is the problem I am having (but not to that extent); the second quote is what I'm trying to achieve (but I'm not sure if the second image's smaller circles are actually precise).

"At any point of my choosing" meaning wherever I desire a smaller circle to be placed along the line of the larger one...

[EC71PZ]

I'm pretty sure MEB knows what I'm talking about.

[EC71PZ]

20 minutes ago, Old Bruce said:

I got confused by your two statements in the post preceding my question, so here is a picture

At any point of your choosing could mean... 

If you change the color and opacity on the circles and zoom in is every circle perfectly aligned with the larger one or no?

[Old Bruce]

4 minutes ago, EC71PZ said:

If you change the color and opacity on the circles and zoom in is every circle perfectly aligned with the larger one or no?

This was done by using the power duplication and rotating around the centre of the large circle. I have no horse in this race so I'll let you check, you cannot as far as I know snap a circle's circumference to another circle's circumference using Designer or Photo or Publisher.

Untitled.afdesign

 

[EC71PZ]

5 minutes ago, Old Bruce said:

This was done by using the power duplication and rotating around the centre of the large circle. I have no horse in this race so I'll let you check, you cannot as far as I know snap a circle's circumference to another circle's circumference using Designer or Photo or Publisher.

Untitled.afdesign

 

Yeah, same problem I have. If you zoom in you will notice some smaller circles overlap the larger circle and others aren't aligned with the edge of the larger circle. I need every smaller circle precisely aligned.

[EC71PZ]

Switch between the View Points I've created in the Navigator panel to see what I mean.

Thank you,
EC71PZ

Unt2.afdesign