Based Sketches, Closed Profiles and Self-Intersection

[mech-eng]

Would you please explain what "closed profiles" mean and what self-intersection is?
"Both single and multiple sketches may be used as the base objects for this feature.Base sketches must include closed profiles and may not be self-intersecting."

Would you explain what "base sketches", "base objects", "closed profiles" and "self-intersection" mean in the link?
https://www.sharcnet.ca/Software/Ansys/17.0/en-us/help/wb_dm/dm_SufacesFromSketches3DMod.html

Thank you.

 

[Nidum]

 

[mech-eng]

Are the first one just a "closed profile" and the second "open profile"?

Thank you.

 

[jedishrfu]

This information is readily available if you use a google search. I did and here's what I found:

Self intersecting:

https://en.wikipedia.org/wiki/List_of_self-intersecting_polygons

Open vs closed profile:

https://forums.autodesk.com/t5/inventor-ideas/sketch-closed-profile-indicator/idi-p/6274511

When searching these kinds of topics it may be made more difficult because of the relative commonness of the words but if you persist and use image search too then you can often find what you're looking for. If after searching you still have some confusion then you can post what you've found and ask your question more confidently.

 

[Bandit127]

If you are asking with the background being Solidworks then the first profile can be extruded. The second not and the third probably not.

 

[mech-eng]

when we are dealing with sketches here, I also would like to ask why a simple line cannot be revolved around an axis? Let's think that line as a pencil. Put it horizontally and parallel to x-axis above the x-axis. Then if we start to turn it around the axis I think there should be a solidbody with space inside it. My instructor said I could not revolve a line but would revolve a closed sketch such as a rectangle.

Thank you.