Distortable Circle

Is there a way to draw a 'circle' using Autocad (or any other drafting/ graphics software) that allows one to 'drag' the corner and side
handles (one at a time) and distort the circle, so that a continuous curve is maintained, but the starting circle is now a free-form shape?
In my experience, the side handles give a 'transient' ellipse which collapses to a smaller or larger circle with a new center.
Thanks,
baumgrenze
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Not in Acad. A circle has a standard relationship between the center and the perimeter.
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MichaelB
www.michaelbulatovich.ca
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In a previous post baumgrenze wrote...

A circle or ellipse has 5 handle points counting the center. To be able to distort the shape as you describe would require more than 5 points. It may be possible to trace over a circle or ellipse with a multi-point polyline and then you can stretch it in any direct you wish, but it will still be a series of line segments not a continuous curve.
There is a type of curve that may be what you are after. It's called a bezier and can be pulled and stretched in many directions depending on the number of points in the curve. I don't think ACad can draw that type of curve, but other some other cad softwares can, Visualcadd for one.
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Bob Morrison, PE, SE
R L Morrison Engineering Co
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What about offsetting an "ellipse" and then the grips are independently adjustable?
Maybe I'm not fully understanding what the person is trying to do?
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Works for me. Create a symmetric ellipse then offset it.
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Bob Morrison, PE, SE
R L Morrison Engineering Co
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Bob Morrison wrote:

the code for a circle is center point & radius. acad used to start with a series of arcs to approximate an ellipse, now it is one entity. /God be praised..
/unfortunately, from my point of view, at least in my old version, when you offset an ellipse you get all those arcs again. back to the original way, which always was inferior.
if I want to make an ellipse bigger or smaller and maintain the aspect I would scale it. if I want a different aspect, I draw a new ellipse.
but I suspect there is more to the original post than I am mulling over here.
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In a previous post roy wrote...

The original question was:
Is there a way to draw a 'circle' using Autocad (or any other drafting/ graphics software) that allows one to 'drag' the corner and side handles (one at a time) and distort the circle, so that a continuous curve is maintained, but the starting circle is now a free-form shape?
The above is possible if the "circle" is a symmetric ellipse that has been offset some distance.
1. Create an ellipse with x and y axes symmetrical. This will look look a circle.
2. Offset (or parallel) the ellipse. It will now have multiple grips, but still look like a circle.
3. Grab any one of the grips and drag in any direction. Free-form shape!
4. It seems to me that you have done what the OP was asking for.
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Bob Morrison, PE, SE
R L Morrison Engineering Co
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Thank you all for your contributions.
It is clear that my goal is a far more complex one than can be realized by an occasional user of Autosketch.
Here is the underlying problem I thought might be approachable using a drafting program.
We wish to evaluate an individual's field of vision. From my limited experience (I'm a retired chemist who has had his eyes checked many times.) a 'normal' field of vision is approximately a circle. I envisioned a test in which a technician could project a circle, and a central focus-of-attention point, and then adjust 1/8th segments of the circle inwards from 'eight points of the compass,' leaving the ends connected, until the individual could just see the projected curve. Small adjustments in and out would be easy to accommodate. The resulting closed curve should be a pretty good map of the individual's field of vision.
Here's another description of the task. Consider a circle to be a cross section of a distortable spherical balloon. Allow the user to 'push' on eight (or perhaps more) uniformly placed points on the circle and to displace them towards an apparent fixed center. Distort the adjacent line segments so that the two next neighboring remain fixed in place and a new continuous curve is maintained between between them.
Perhaps the concept is 'simple' but its execution is non-trivial, at least using drafting software. Perhaps it is more a problem approachable using graphing software.
If this stimulates any alternatives, let's continue the discussion.
Thanks,
baumgrenze

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Try pasting this into the command line:
rec 0,0 100,100 pe l s x ro l 50,50 45
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and if you want the control points on the curve itself then use this:
spline -100,0 0,100 100,0 0,-100 c -100,-100
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In a previous post baumgrenze wrote...

They already have equipment that will do this. It projects dots of light on a spherical field. You indicate which ones you can see by pressing a button. The equipment then plots the resulting dots on a paper disk, which in turn gives your field of vision.
I have this test done every year by my optometrist.
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Bob Morrison, PE, SE
R L Morrison Engineering Co
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