Resolved How to paint a polygon by brush?

Hey guys
Now I want to get a polygon defined by a sorted list of vertex coordinates. For example 4 coordinate ,(0,0) (1,0) (1,1) (0,1), define a rectangle.

And I hope I can use a brush to paint this polygon.

Maybe I can paint a texture like this
and convert it to a list of vertexes just like the little white rect points on the image below. (or piant vertexes immediately)


I had found a question (https://forum.unity.com/threads/how-to-make-field-painter-like-cities-skylines-districts.380061/) asking how to make field painter like cities skylines districts.

There is a answer mentioned about Marching Squares algorithm. After having a quick look on the algorithm, I think it will work great when I just need to visualize the edge of the region.

But now I wanna get a set of vertices sorted counterclockwise. I don't think the algorithm will work in this case.

I don't know how to make my idea come true.

Someone know how to do this? thanks in advance.

 

This problem is a combination of computer vision and constructive geometry.

If you start from a computer vision package such as OpenCV (there is a Unity3D package available on the asset store), that can give you a real leg up on a set of vectors defining the boundary of your area.

From that you could perhaps construct a set of continuous lines forming a polygon.

It's even possible that OpenCV has some kind of polygon-creation helper routines in it nowadays... I haven't used OpenCV since 2014, but I imagine it has had updates.

 

Thank you for your help. I will try this method and see if it can be used on my project.

 

I implemented this function with Boolean operation, and wrote down my method on this page:https://blog.csdn.net/lxbhahaha/article/details/113879102