Reference Talk:Lemon

Opening paragraph needs a bit more information!

• How about something like the following for the text description?

New to version 3.7.1 the lemon object has been added. It is defined by two points in space where each point has an associated radius >=0 defining a disc. A third radius defines an outward spherical curvature connecting the two discs. This third radius must be >= the distance between the two points.

The radius of the discs at the two specified points can be zero. In such cases the shape takes on the form of an American football. Where the disc radius is 0 at one end and >0 at the other, the shape is more like an ogive. Where the disc radius is >0 at both ends, the shape looks something like a barrel.

Both the open and sturm object modifiers are supported.

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My try, could be mixed with your suggestion:

The lemon is similar to a cone, but instead of connecting with a straight line the two circles (see Reference:Cone ) , the connection is done with a circular arc whose radius is the Inner_radius in the lemon syntax.

--Le Forgeron 17:17, 15 September 2016 (UTC)

The third radius must be greater than the radius of the connecting disc with its center on the axis. (the exact equation is painful, but the parser will stop to tell you the smallest allowed value if the provided value is too small).

--Le Forgeron 17:23, 15 September 2016 (UTC)

My bad, I should test instead of relying on wrong memory. The parser is not stopped, but the value is adjusted to the minimal value when it is too small. Great !

I would change :

• end points are connected by a spherically curved Inner_Radius
• generally speaking Inner_Radius must be greater than or equal to half the distance between end points minimal Inner_Radius is defined as sqrt (radius2 + (distance/2)2)
• if the given Inner_Radius is too small the minimal value as defined above is used instead and a warning is issued
• both or either of the end points radii can be zero
• coded constraints on minimal Inner_Radius or when the end points radii are different can have adverse consequences

For

• end points' circles are connected by the revolution surface generated by the circular arc of Inner_Radius whose moving center is on the other side or at most on the axis of revolution defined by the two end points
• for the minimal value of Inner_radius, the surface is a spherical segment (the center of the arc lie on the axis of revolution)
• for bigger value of Inner_radius, the surface is a lemon (inner part of a self intersecting torus), or a frustum of it.
• if the given Inner_Radius is too small the minimal value is used instead and a warning is issued
• both or either of the end points radii can be zero

--Le Forgeron 16:01, 16 September 2016 (UTC)

• We need to move the note above the syntax follows line. I'd also suggest shortening the note as shown.

Note: The minimal Inner_Radius value is defined as: sqrt ( radius² + ( distanceBetweenEndPoints/2 )² ).

The syntax is as follows:

--wfpokorny Sat Sep 17 13:48:26 UTC 2016