Hi Pilou, the one that you are showing the solution for is the special case with points arranged in a particular configuration. I don't believe that your solution works for the more general case where the points are placed anywhere...

- Michael

Well here's my solution http://screencast.com/t/EngogKiRXu6C

I don't know if it's the same as the way shown in bemfarmer's link, as that was hard for me to follow, but somehow I got to work it out OK.

Martin (2)

Hi Martin, I'm glad that you got it solved. I will look into adding this case into the circle and arc tangent commands.

- Michael

So for your special case :) (I have made a general rotation for more practical explanation ;)




Cool movie solution of the mirror trick !

>>Hi Martin, I'm glad that you got it solved. I will look into adding this case into the circle and arc tangent commands.

>>- Michael

Michael.

That would be nice if you can do it and definitly appreciated by me - not because I perform this particular manoeuvre on a daily basis, but it would be one less interruption to hamper workflow when the need arises.

Well apart from this one case, I must say that I tried quite a few different tangent intersection scenarios and have come away very impressed with the logic built in to MoI and its ability to find the right solution. Most software seems to either give a null result or insist on jumping to the wrong side of the arc when doing one of the more unusual kinds of blend.

Thanks to all for helping.

Martin (2).

Martin(2), your mirror by midpoint method, with construction line and circle tangent command is very nice.
In your example, there are two circle solutions. There are other cases...




I've never studied inversion/reflection in a circle, nor radical axis, and haven't grasped it yet. Here are a couple of pdf's on the subject:

http://geometer.org/mathcircles/inversion.pdf

http://jwilson.coe.uga.edu/MATH7200/InversionCompanion/inversion/inversionSupplement.pdf

So what would a MoI command to invert some geometry, with some circle do?