Re: [Visualpython-users] bug in vpython path library

[Bruce S. <Bru...@nc...>]

I'm afraid this is a feature, not a bug. There just isn't any way that
I can think of for such a sharp turn to work in something called an
"extrusion". Think about creating such an object by extruding metal
and you may see that this is a fundamental problem.

In the example program "extrusion_overview.py", step through the first
page to get an index, then choose page 12 to see an illustration of
the problem.

On the other hand, perhaps you or someone else can come up with some
scheme that would work better.

Bruce Sherwood

On Mon, Apr 16, 2012 at 8:12 PM, sufyan fehe <sis...@ya...> wrote:
> I am using the extrusion object library, path library of Vpyhon for my
> project. my program simply extracts or parses G-codes with X,Y, Z
> coordinates, the program then uses this extracted points as my path, a 2D
> square shape is then extruded through these points or path in that sequence.
> the problem is, these points are line segments, where a line segment is
> define by two points i.e X1,Y1,Z1 and X2,Y2,Z2. Now if the third point
> X3,Y3Z3 is sharp turn, i.e the angle between the line segment becomes > 270,
> the extrusion generates very long spikes or glitches which makes my work
> messy. my G-codes are all accurate, because it is tested. this is a special
> case where the preceding point makes that sharp turn. i showed it to some
> programmers and they say it might be a bug with vpython extrusion library. i
> can share my program with you, or pictures of what i mean. hope i get a
> response from you. thanks
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