Polygon Distance Field

[micycle1]

Start with a polygon.

Triangulate!

Build a directed graph of adjacent triangles starting with some triangle as the root. Use the building process to insert copies of the triangle vertices into another tin with certain Z values.

For a given vertex and given triangle, the Z value is computed from the sum of inter-circumcircle distances from the triangle's parent to the root triangle + the euclidean distance from the parent's circumcircle to the vertex.

(Here each triangle is coloured individually based on sum of triangle inter-circumcircle distances from its circumcircle to the root, which already looks convincing for such a shape because it is fairly thin throughout).

Interpolate. Apply NaturalNeighborInterpolator to the new Tin, iterating pixel by pixel to produce a Z value for each pixel.

Mask the interpolated distance field with the original polygon.

[gwlucastrig]

That is just so cool! Thanks for posting it. Excellent work!

…

On Sun, Mar 21, 2021, 12:49 PM Michael Carleton ***@***.***> wrote: Start with a polygon. [image: image] <https://user-images.githubusercontent.com/9304234/111912229-a71b2680-8a60-11eb-866a-c74051965c16.png> Triangulate! [image: image] <https://user-images.githubusercontent.com/9304234/111912241-b306e880-8a60-11eb-9f6d-4e0fe66ba255.png> Build a directed graph of adjacent triangles starting with some triangle as the root. Use the building process to insert copies of the triangle vertices into another tin with certain Z values. For a given vertex and given triangle, the Z value is computed from the sum of inter-circumcircle distances from the triangle's parent to the root triangle + the euclidean distance from the parent's circumcircle to the vertex. (Here each triangle is coloured individually based on sum of triangle inter-circumcircle distances from its circumcircle to the root, which already looks convincing for such a shape because it is fairly thin throughout). [image: image] <https://user-images.githubusercontent.com/9304234/111912094-088ec580-8a60-11eb-9414-d23750279a15.png> Interpolate. Apply NaturalNeighborInterpolator to the new Tin, iterating pixel by pixel to produce a Z value for each pixel. [image: image] <https://user-images.githubusercontent.com/9304234/111912126-2bb97500-8a60-11eb-8ca4-e2933960a392.png> Mask the interpolated distance field with the original polygon. [image: image] <https://user-images.githubusercontent.com/9304234/111911599-2d823900-8a5e-11eb-93b0-5d569e3b2daa.png> — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#67>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AEWJDYMF2GAG2BA33JKIMJLTEYPTBANCNFSM4ZRXL5WA> .