Hi my friend,
I try to divide mesh vertices with point in brep node using voronoi cells as input breps, but after cull pattern operation, my resulted total points ( vertexes ) are more than the input points ( vertexes ), what happens? I don’t understand.

If you’re goal is to group the mesh vertices into clusters per Vornoi cell, your on the right track! You need to inclusion check every vertex for each cell, which you already do.

On a more general note, I would use simplify more sparingly. There’s really no need to simplify each and every output. You can use Trim (TrimTree) and similar components the adjust paths and use simplify only if absolutely necessary. Each time you simplify, you lose historical information, which might get you into trouble further down the line.

After culling, you get 3648 points, which correspond to the number of vertices you started with, meaning that all vertices where partitioned into groups per brep, which was the goal right?

Hi diff-arch,
Thanks for your kindly reply, much appreciated. You are right. I shouldn’t frequently use the simplify that removes the historical information.
Indeed my goal is grouping these input points ( mesh vertexes ) into Vornoi cells. Then as you point out, there are 3648 points, which this is more than the input points 3644, 4 more. I wonder if this 4 more are points on the wall of two cells which counts twicem, or other thing. I couldn’t figure out. These points count is variant with different amount of cells inputting. I try it shape in brep node. It works find that the total amount of calculated points is matching with the input points 3644. I get very confused.

Yes, these are probably vertices that lie on the boundary between two cells and thus are part of two or more clusters.
You can set the Strict input of the inclusion check to False to get rid of theses points.