**Next message:**C. Brock Rooney: "Re: Adaptive slicing problems."**Previous message:**International Symposium on Industrial Electronics: "(no subject)"**In reply to:**Raymond Hope: "Adaptive slicing problems."**Next in thread:**Raymond Hope: "Re: Adaptive slicing problems."**Reply:**Raymond Hope: "Re: Adaptive slicing problems."**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ] [ attachment ]

Might the first problem be solved by not using STL files in the first

place? Would DXF files be more workable?

At 12:49 PM +1000 2/24/97, Raymond Hope wrote:

*>Hi all;
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*>
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*>My name is Ray Hope. I've been working on slicing procedures for layered
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*>manufacturing, and am using layers with sloping boundary surfaces to
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*>eliminate the stair case effect. I have recently been working on adaptive
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*>slicing, and have come across some cases that can cause problems. So I
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*>thought I should call on the greater collective knowledge of the group and
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*>see if we can come up with some ideas.
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*>
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*>Note I am obtaining the definition of parts from B-spline surfaces. Layer
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*>error is approximated from the radius of curvature and angle of the
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*>surface normal.
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*>
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*>Problem 1.
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*>
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*> Joins between two or more surfaces, and vertices can cause the error
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*>approximation to give incorrect results. Previously published work (by
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*>others) has tried to solve this problem by slicing the part so that the
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*>surface joins coincide with layer joins. However this can only work if the
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*>surface joins are in the same plane as the layers. In many cases where a
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*>part is defined by two intersecting surfaces, the intersection curve is not
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*>in the layer plane. So what do we do?
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*>
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*>Problem 2.
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*>
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*> The method mentioned above to predict the error, produces a predicted
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*>error much less than the true value near inflection points. This is
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*>because at an inflection point the curvature becomes zero, and is also very
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*>small nearby. So how should we predict error near inflection points?
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*>
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*>
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*>I look forward to hearing some interesting suggestion from all of you.
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*>
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*>Thanks
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*>Ray Hope
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*>Department of Mechanical Engineering
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*>The University of Queensland
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*>Brisbane QLD 4072
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*>AUSTRALIA
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*>
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*>Ph +61 7 3365 4179
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*> Home +61 7 3217 7410
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*>
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*>Facsimile +61 7 3365 4799
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*>Email: hope@mech.uq.edu.au
*

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