4 Replies Latest reply on Jun 4, 2015 12:20 AM by Chaitanya Bade

Conventionally a cylindrical face addressed differently in topology. It has one face and two edges – this means going by the number of the faces it should have only one loop whereas going by the edges, which outer and not connected, it should have two lo

Chaitanya Bade Jun 2, 2015 1:29 AM

Hi,

I need help regarding this question as soon as possible.

Conventionally a cylindrical face addressed differently in topology.

It has one face and two edges – this means going by the number of the faces it should have only one loop whereas going by the edges it should have two loops , which outer and not connected,. Thus the representation has two loops. But the question is how to differentiate between the two loops because both qualify as outer?

The question is, how to differentiate both two loops.\

i am giving some snaps of the part.

as there is a single cylindrical face in the figure, the single face should have onlu one outer loop, but figure shows it is having two outer loops in figure1 and figure2

figure1

fogure2

then how can i explain and differentiate that the single face has two outer loops?.....could you please give me the answer...............thanks in advance.

Re: Conventionally a cylindrical face addressed differently in topology. It has one face and two edges – this means going by the number of the faces it should have only one loop whereas going by the edges, which outer and not connected, it should have tw

Jamil Snead Jun 2, 2015 12:26 PM (in response to Chaitanya Bade)

I think once you move from 2D to 3D surfaces then "outer" and "inner" kind of lose their meaning. You just have loop(s). In the cylinder example, you say that both edges should be considered outer loops. If the cylinder becomes slightly conical, say 1 degree of taper, would it still be 2 outer loops? At some point you would consider the smaller edge to be an inner loop like when it becomes a belleville washer. Since the transition point is subjective I don't think there is any point in trying to label outer and inner loops. Just treat all loops as equals.
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- Re: Conventionally a cylindrical face addressed differently in topology. It has one face and two edges – this means going by the number of the faces it should have only one loop whereas going by the edges, which outer and not connected, it should have tw
  
  Chaitanya Bade Jun 3, 2015 12:21 AM (in response to Jamil Snead)
  
  Hi Jamil,
  the question is again rise for the following figure.
  For the cylinder, i made revolve cut on it, the created cylindrical surface gives me two outer loops as shown in figure 1 &2.
  In the solid modeling , is it possible to have more than one outer loop for a face? if yes, how to justify it?
  
  figure1
  
  figure2
  
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  - Re: Conventionally a cylindrical face addressed differently in topology. It has one face and two edges – this means going by the number of the faces it should have only one loop whereas going by the edges, which outer and not connected, it should have tw
    
    Jamil Snead Jun 3, 2015 1:02 PM (in response to Chaitanya Bade)
    
    I am probably missing something. What do you mean when you say it "gives you two outer loops"? Are you using some sort of command that is supposed to select an outer loop, and that is selecting both loops? What do you mean by ho to justify it? Are you running into some problem because the surface has two edges?
    
    My original point was that the surface has two open loops, why do you care if they are considered "outer" or "inner"? If you want to reference one you just select the one you want.
    
    One test with SW seems to imply that these surfaces actually have no outer loops. If you start a 3D sketch, select the cylinder or the ring surface, then try to convert entities you will get an error saying "Selected face does not have a peripheral loop." If you do the same with a flat surface then the outer loop will convert.
    
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    - Re: Conventionally a cylindrical face addressed differently in topology. It has one face and two edges – this means going by the number of the faces it should have only one loop whereas going by the edges, which outer and not connected, it should have tw
      
      Chaitanya Bade Jun 4, 2015 12:20 AM (in response to Jamil Snead)
      
      Answer of your first que is: the face made by revolve is spherical one. It has two edge. If we look at that face it must have two loops, 'what type of loops they are?' is the query. When i ask that face to give me the type of both loops, it gives type as outer loop in SolidWorks.
      
      I mean to say, if the face having two open loops then why we call it as outer ?, why couldn't say one inner and one outer?
      
      And i got the answer as, for such spherical or cylindrical faces parasolid gives us winding loops and SolidWorks marks those winding loops as outer loops. Thats it!
      
      Thanks Jamil!!!
      
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