Why not Diameter handles on a Cylinder?

Question: As a beginner, I find the designations L, W and H a bit confusing to use on a round Cylinder mold. Would it be easier to just use the handles D (for Diameter) instead of W and L?

The handle H could even be called L as in Length with?

Answer: Yes, especially when you think of a round cylinder shape, it's obviously not a perfect fit.

But keep in mind that length, Width and Height represent the shape of a "Sizebox" (just as X, Y and Z represent directions) and that the round handles on each side are used to "resize this virtual square volume box".

What is then in a Sizebox can be a geometry that "100% fills the box" - a "Block". But it can also be a shape that only "partially fills the box", like a "Spherical shape" or a "Cylindrical shape" etc.

So it is this "virtual box" that you change the shape of, and the geometry in it must follow somehow. For a round cylinder mold, it will then automatically always be the W and L handles that represent its "diameter". The H handle in turn always corresponds to "extrusion height" (yes, it is perhaps simpler to say length, but L is "already occupied" by Length-handle for the length of the sizebox).

Of course, what fills the volume doesn't even have to be symmetrical, but then you should preferably no longer use the Sizebox handles to change the shape, because they "stretch" the geometry of the volume (actually the lines in the sketch) by a percentage in the direction you drag.

If you pull the W handle, the lines of the sketch in that direction will be longer, but the lines going in the L direction will also "follow" and move accordingly and vice versa. See the picture below.

Then there's another type of super smooth handle that's more suitable - the Shape handles!

They are also called "profile handles" because they appear one at a time on the contour line (in the "profile") that you touch with the mouse pointer. These are used to draw directly on the sketch lines, one at a time. But more about that in another post.

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