Level Set Method and Immersed Interface Method

mykkujinu2201 · July 7, 2017, 03:37

Dear all,

I am a master course student who is currently doing research using Immersed Interface Method and Level Set Method. Now, I am trying to represent my surface with signed distance function. I can calculate the minimum distance easily, but I don't know how to determine whether the grid point is inside or outside of the surface.
I have searched about the method but usually they gave me a simple example like circle which can be represented with exact function. Specifically, I want to know how to get the initial level set function with discrete surface control points.
Is there anyone who can help me?

Jun

leflix · August 5, 2017, 12:48

Hi,

In the level set method the distance function is a signed function. If it is positive you are in fluid 1 (inside the surface), if it is negative you are in fluid 2 (outside the surface). Of course it depends on the way you initialized this function according what is for you inside or outside or (fluid1 or fluid 2).
Leflix

sbaffini · August 5, 2017, 13:31

There is a variety of methods. The basic one uses raytracing, but you need a smart data structure for your surface. What method do you use for your distance calculation? There are chances that you can use that with a simple check to also determine the side.

July 7, 2017, 03:37	Level Set Method and Immersed Interface Method	#1
mykkujinu2201 Member Jun Join Date: Nov 2015 Posts: 57 Rep Power: 11	Dear all, I am a master course student who is currently doing research using Immersed Interface Method and Level Set Method. Now, I am trying to represent my surface with signed distance function. I can calculate the minimum distance easily, but I don't know how to determine whether the grid point is inside or outside of the surface. I have searched about the method but usually they gave me a simple example like circle which can be represented with exact function. Specifically, I want to know how to get the initial level set function with discrete surface control points. Is there anyone who can help me? Jun

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August 5, 2017, 12:48		#2
leflix Senior Member Join Date: Aug 2011 Posts: 272 Rep Power: 16	Hi, In the level set method the distance function is a signed function. If it is positive you are in fluid 1 (inside the surface), if it is negative you are in fluid 2 (outside the surface). Of course it depends on the way you initialized this function according what is for you inside or outside or (fluid1 or fluid 2). Leflix

August 5, 2017, 13:31		#3
sbaffini Senior Member Paolo Lampitella Join Date: Mar 2009 Location: Italy Posts: 2,195 Blog Entries: 29 Rep Power: 39	There is a variety of methods. The basic one uses raytracing, but you need a smart data structure for your surface. What method do you use for your distance calculation? There are chances that you can use that with a simple check to also determine the side.