Polygon intersection

Polygon intersection - Messages

#1 Posted: 5/17/2020 4:24:07 PM
SteelCat

SteelCat

3 likes in 47 posts.

Group: User

Hi everyone,
I'm looking for suggestions to find the intersection of two polygons and hatch the result.

The most particular case concerns the hatching of a part of polygon intersected by a straight line.

I know some basic of X-Y plot to draw a polygon...
Physics is like sex. Sure, it may give some practical results, but that’s not why we do it. (R. Feynman)
#2 Posted: 5/17/2020 5:12:07 PM
Martin Kraska

Martin Kraska

1222 likes in 2150 posts.

Group: Moderator

Perhaps the GPC (general polygon clipping library) wrapper plugin might help. The basics are described in section G.3 of the german handbook.

You also might have a look at the hatch and fill snippet.


GPC.sm (6 KiB) downloaded 105 time(s).

2017-03-29 14_54_45-SMath Studio 0.98.6179 - [Blatt1_].png
Martin Kraska Pre-configured portable distribution of SMath Studio: https://en.smath.info/wiki/SMath%20with%20Plugins.ashx
1 users liked this post
frapuano 5/18/2020 4:10:00 AM
#3 Posted: 5/18/2020 11:04:20 AM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

Otherwise, piece wise from native Smath ... just demo.

Circular Polygon.sm (20 KiB) downloaded 41 time(s).
#4 Posted: 5/18/2020 12:31:53 PM
Alvaro Diaz Falconi

Alvaro Diaz Falconi

992 likes in 1674 posts.

Group: User

Hi. Maybe you also can check this discussion: https://en.smath.com/forum/yaf_postst11405_Line-intersections.aspx

Best regards.
Alvaro.
#5 Posted: 5/18/2020 8:56:55 PM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

IMHO, I don't see much interest for polygon intersection.
For your interest: Intersection Pentastar.

Maths Polygon Solve Intersection.sm (21 KiB) downloaded 35 time(s).
Maths Polygon Intersection Pentastar.sm (35 KiB) downloaded 32 time(s).
#6 Posted: 5/18/2020 10:32:09 PM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

Wrote

For your interest: Intersection Pentastar.


...labels added, superb for publishing.

Maths Polygon Intersection Pentastar.sm (47 KiB) downloaded 39 time(s).
#7 Posted: 5/19/2020 11:38:48 AM
SteelCat

SteelCat

3 likes in 47 posts.

Group: User

thank you all, I will do some application
Physics is like sex. Sure, it may give some practical results, but that’s not why we do it. (R. Feynman)
#8 Posted: 5/23/2020 6:37:34 AM
ianlh

ianlh

0 likes in 38 posts.

Group: User

Question:

How would you then calculate / determine the length of the clipped line?
Interested for tension and shear lengths in unusual shapes
#9 Posted: 5/23/2020 11:24:32 AM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

... refreshed/generalized/augmented [A, P, CG]

2D Plot Setup Critical Polygon Intersection.sm (31 KiB) downloaded 38 time(s).
#10 Posted: 5/23/2020 1:04:57 PM
Jean Giraud

Jean Giraud

983 likes in 6866 posts.

Group: User

Wrote

How would you then calculate / determine the length of the clipped line?
Interested for tension and shear lengths in unusual shapes


From the attached Smath document.
#11 Posted: 5/23/2020 1:11:13 PM
SteelCat

SteelCat

3 likes in 47 posts.

Group: User

Wrote

Question:

How would you then calculate / determine the length of the clipped line?
Interested for tension and shear lengths in unusual shapes



From coords, using Pitagora's theorem

Wrote

... refreshed/generalized/augmented [A, P, CG]

2D Plot Setup Critical Polygon Intersection.sm (31 KiB) downloaded 38 time(s).



Very nice.

Physics is like sex. Sure, it may give some practical results, but that’s not why we do it. (R. Feynman)
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