将列表/网格划分为子列表/子网格

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问题描述

给出一个关于我拥有哪种类型的网格的想法:

想象一下一个乐高积木，顶部有四个旋钮.我读了一个包含整个砖块表面的STL文件.在确定了所有具有唯一坐标的节点(并将其下一个邻居保存在列表中)之后，我切掉了大部分积木，以便仅保留四个旋钮.不幸的是，这四个旋钮仍然在一个大列表中(一个用于节点，一个用于下一个邻居).如果我指定一个我知道属于该旋钮的节点，我想以最快的方式获得一个旋钮的所有节点.

我有一个(相对)大的List<cNode> nodes其中

I have a (relatively) big List<cNode> nodes where

class cNode
{
    int nodeNumber;
    cVector vector;
}

甚至更大(约14e6个条目)List<cNodeCoincidence> coincidences其中

and an even bigger (ca. 14e6 entries) List<cNodeCoincidence> coincidences where

class cNodeCoincidence
{
    cNode node1;
    cNode node2;
}

我的节点代表3D点，而我的巧合类似于以前由STL文件压缩而成的由三角形组成的网格.我知道一个事实(用户相应地进行了输入)，我的节点网格实际上是一个节点/巧合列表中的4个单独的网格.我的目标是将每个子网格的节点提取到其自己的节点列表中.为此，我从每个子网格的一个节点开始，我知道它是所述子网格的一部分.提示一个递归函数:

My nodes represent points in 3D and my coincidences resembles what was formerly a mesh consisting of triangles, condensed from a STL file. I know for a fact (and the user made his input accordingly), that my node-mesh is actually 4 seperate meshes in one node/coincidence list. My goal is to extract the nodes of each sub-mesh to its own nodelist. To achieve this, I start with one node for each sub-mesh, which I know to be part of said sub-mesh. Cue a recursive function:

private void AssembleSubMesh(ReadOnlyCollection<cNode> in_nodesToRead, List<cNode> in_nodesAlreadyRead)
{
    List<cNode> newNodesToRead = new List<cNode>();
    List<cNodeCoincidence> foundCoincidences = coincidences.Where(x => (in_nodesToRead.Any(y => y == x.node1)) || in_nodesToRead.Any(z => z == x.node2)).ToList();
    in_nodesAlreadyRead.AddRange(in_nodesToRead);
    List<cNode> allRemainingNodes = new List<cNode>();
    foreach (cNodeCoincidence nc in foundCoincidences)
    {
        allRemainingNodes.Add(nc.node1);
        allRemainingNodes.Add(nc.node2);
    }
    allRemainingNodes = allRemainingNodes.Distinct().ToList();
    allRemainingNodes.RemoveAll(x => in_nodesAlreadyRead.Contains(x));
    if (allRemainingNodes.Count != 0)
        AssembleSubMesh(new ReadOnlyCollection<cNode>(allRemainingNodes), in_nodesAlreadyRead);
}

，它被AssembleSubMesh(new ReadOnlyCollection<cNode>(firstNodeIKnow), globalResultListForSubmesh);调用，从而将递归的结果写到一个更全局的列表中.

which is called by: AssembleSubMesh(new ReadOnlyCollection<cNode>(firstNodeIKnow), globalResultListForSubmesh); thus writing the results of the recursion to a more global list.

此过程可以工作(使用小网格物体进行测试)，但是非常缓慢(在我中止该过程之前的15个小时之内).

This procedure works (tested with small mesh), but is painfully slow (over 15 hours before I aborted the process).

有没有办法以更快，更优雅的方式分离网格?

我找到了这篇SO帖子，并查看了本讲座，看来，这(特别是WQUPC)可能是我所需要的，但是我不明白它到底有什么帮助，因为它们只有一个节点列表，而且我还有一个巧合列表，如果真的不使用它，那真是不好意思(?).

I found this SO post and had a look at this lecture and it seems, that there might be a chance that this (especially WQUPC) is what I need, but I don't understand how exactly it could help, because they only have a node list and I additionally have the coincidence list which would be a shame not to use, really (?).

数据库能帮上忙吗(由于建立索引)?

Could a database help (because of indexing)?

coincidences

将列表/网格划分为子列表/子网格

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