When I use the tool: tangent to two entities, through a point, and the point belongs to one of the two entities, Qcad does not solve the problem.
Works well if there are two lines,
but if it is a line and a circle gives false solutions,
and if it is two circles say that there is not solutions.
Tested in Debian Gnu/linux 10 and Qcad 3.26.4.0
tangent to two entities, through a point, when the point belongs to one of the two entities
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Post one question per topic.
Re: tangent to two entities, through a point, when the point belongs to one of the two entities
Sorry, never heard about a tool called "Tangent to two entities". I know about a tool called "Tangent two circle (LT2) which works between two circle. Is that the tool what you refer to?
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Win10/64, QcadPro, QcadCam version: Current.
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Win10/64, QcadPro, QcadCam version: Current.
If a thread is considered as "solved" please change the title of the first post to "[solved] Title..."
Re: tangent to two entities, through a point, when the point belongs to one of the two entities
mangel: please attach your drawing file with the two tangential entities and indicate which exact tool you are using, thanks.
Re: tangent to two entities, through a point, when the point belongs to one of the two entities
Draw circle tangential to two entities, through a point (CT2).
Andrew, all my findings are in the attached dxf files ... Not limiting.
- With 2 lines and a point on one of the lines QCAD presents 2 correct solutions.
The indicated point is then the (forced) tangent point with that line.
Solutions reduce to one unique if the lines are parallel.
- With a circle, a line and a point on the line QCAD may present 4 solutions of which none is correct.
If the indicated point is exactly the center projected perpendicular on the line, a lucky shot or by an auxiliary line, ...
... then 2 correct solutions are presented.
With 4 solutions it is clearly visible that the indicated point is an intersection with the line and that all the solutions intersect twice. For the correct solutions:
The tangent point of two circles is on a line through both centers. (Cyan)
And the center of a circle tangent to a line is on a line orthogonal in the tangent point. (Blue)
One can find these correct solutions by the intersection of 2 incorrect solutions.
- Analog with a line, a circle and a point on the circle.
- With two circles there will not be a solution for a point inside one of the circles.
The solution can't be and tangent to and crossing the circle at the same time.
For a point outside the circles 4 solutions may be presented. Not all 4 are correct in all cases. For a point on one of the circles there are no solutions presented.
These can be found by mirroring the other circle over the symmetry axis center - point and matching solutions of 3 tangents (CT3).
This knowledge is gathered in the past few months while I investigated how to round all corners of bulging polylines.
It boils down to what is considered tangent, what is the intersection of two circles, and how arc segments are prepended/appended to a polyline.
The tool is perfectly functional up to a point where the numbers don't add up anymore. They should mathematically.
Regards,
CVH