Topic: slice 1 solid multiple times

[ArgV]

I'm having trouble here.

I want to slice all four edges off the rectangles I am making, however, to use the vla-slidesolid method, you need a solid object. Thats fine at first, but once you slice a solid, it becomes two objects. It seems like the original solid, instead of just updating, creates and entirely new object. Is there a way to keep the main solid as your "object"?

thanks,

ArgV

[Lee Mac]

I've never used that method, but if what you are saying is correct, why not just use the newly created objects as your "object" as you say?

[ArgV]

I've never used that method, but if what you are saying is correct, why not just use the newly created objects as your "object" as you say?

That works the first time, but if I do that a second time, then it slices the small object, not the big one.

[Lee Mac]

I've never used that method, but if what you are saying is correct, why not just use the newly created objects as your "object" as you say?

That works the first time, but if I do that a second time, then it slices the small object, not the big one.

Perhaps test the objects for which is bigger?

[SEANT]

The side of a sliced solid left as the original is the portion on the positive side of the plane (the negative side would be a new object).  The positive side is determined in the same way the positive Z direction is determined in the UCS – 3point.  These procedures follow the “Right Hand Rule” for vector cross product where “a” is the point1 to point2 , “b” is point2 to point3.

http://images.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/Right_hand_rule_cross_product.svg/507px-Right_hand_rule_cross_product.svg.png&imgrefurl=http://commons.wikimedia.org/wiki/File:Right_hand_rule_cross_product.svg&usg=__RJzt3VKNmBmKNrGoF7ycn7wLaE8=&h=459&w=507&sz=35&hl=en&start=16&um=1&tbnid=mqmh9HNF9WO8eM:&tbnh=119&tbnw=131&prev=/images%3Fq%3Dright%2Bhand%2Brules%26hl%3Den%26sa%3DX%26um%3D1

[ArgV]

The side of a sliced solid left as the original is the portion on the positive side of the plane (the negative side would be a new object).  The positive side is determined in the same way the positive Z direction is determined in the UCS – 3point.  These procedures follow the “Right Hand Rule” for vector cross product where “a” is the point1 to point2 , “b” is point2 to point3.

http://images.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/Right_hand_rule_cross_product.svg/507px-Right_hand_rule_cross_product.svg.png&imgrefurl=http://commons.wikimedia.org/wiki/File:Right_hand_rule_cross_product.svg&usg=__RJzt3VKNmBmKNrGoF7ycn7wLaE8=&h=459&w=507&sz=35&hl=en&start=16&um=1&tbnid=mqmh9HNF9WO8eM:&tbnh=119&tbnw=131&prev=/images%3Fq%3Dright%2Bhand%2Brules%26hl%3Den%26sa%3DX%26um%3D1

Ok, so how to I tell my program to always slice the "big" solid?

[Lee Mac]

This will help you:

Code: [Select]

;; Vector Cross Product (Lee Mac)
;; Args: a,b Vectors

(defun cross (a b)
  (list (- (* (cadr a)  (caddr b))
           (* (cadr b)  (caddr a)))
        (- (* (car  b)  (caddr a))
           (* (car  a)  (caddr b)))
        (- (* (car  a)  (cadr  b))
           (* (car  b)  (cadr  a)))))


[Lee Mac]

Alternatively, you could just compare the volumes... 

[ArgV]

Alternatively, you could just compare the volumes... 

well, in this case it's easier just to make the big solid smaller and just "add" the edging to the sides afterwards, rather than slicing it. Hmm.. well thank you!