我一直在尝试优化如何在Quad Sphere的Top和Bottom面以及其余面中查找Quad Tree面的邻居。我尝试了几种方法来确定邻居，最新的方法提高了查找速度，但是我想知道是否还有更好的方法
方法1：
保留所有Quad使用的所有顶点的所有用户的查找表，然后对于每个Quad，查找不是祖先与原始Quad共享边缘顶点的其他任何Quad（减去拐角顶点，因为它们是共享的由多个非邻居）。这对于少量的细分和顶点非常有用，但是随着每个细分和顶点的增加，性能会变得更差。 请参见此实现示例：https://github.com/bicarbon8/QuadSphere/blob/master/Assets/Scripts/QuadVertMap.cs#L104
方法2：
保留每个细分级别的所有Quad的查找表，并按级别进行索引，然后为每个Quad查找不是祖先的同级或少一级（父级）的其他Quad，并检查其边缘顶点以查看它们是否与原始Quad的边缘顶点匹配。这比方法1更好，但是如果您对细分级别的了解太深，它仍然会受到影响。看起来像下面的代码片段：
public Quad FindNeighbor(Quad quad, EdgeType edge)
{
Vector3[] edgeVerts = quad.GetWorldVerts(quad.GetEdgeVerts(edge));
int level = quad.GetLevel(); // neighbors can only be equal or 1 lower level
List<Quad> potentialNeighbors = Quads[level].Where(n => n != quad).ToList();
if (potentialNeighbors.Any())
{
foreach (Quad potentialNeighbor in potentialNeighbors)
{
var topEdge = potentialNeighbor.GetWorldVerts(potentialNeighbor.GetEdgeVerts(EdgeType.Top));
if (topEdge.All(v => edgeVerts.Contains(v)))
{
return potentialNeighbor;
}
var bottomEdge = potentialNeighbor.GetWorldVerts(potentialNeighbor.GetEdgeVerts(EdgeType.Bottom));
if (bottomEdge.All(v => edgeVerts.Contains(v)))
{
return potentialNeighbor;
}
var leftEdge = potentialNeighbor.GetWorldVerts(potentialNeighbor.GetEdgeVerts(EdgeType.Left));
if (leftEdge.All(v => edgeVerts.Contains(v)))
{
return potentialNeighbor;
}
var rightEdge = potentialNeighbor.GetWorldVerts(potentialNeighbor.GetEdgeVerts(EdgeType.Right));
if (rightEdge.All(v => edgeVerts.Contains(v)))
{
return potentialNeighbor;
}
}
}
if (level > 0)
{
// if we made it this far we haven't found a neighbor yet so try 1 level lower Quads
potentialNeighbors = Quads[level - 1].Where(n => n != quad.GetParent()).ToList();
if (potentialNeighbors.Any())
{
foreach (Quad potentialNeighbor in potentialNeighbors)
{
var topEdge = potentialNeighbor.GetWorldVerts(potentialNeighbor.GetEdgeVerts(EdgeType.Top));
if (topEdge.Any(v => edgeVerts.Contains(v)))
{
return potentialNeighbor;
}
var bottomEdge = potentialNeighbor.GetWorldVerts(potentialNeighbor.GetEdgeVerts(EdgeType.Bottom));
if (bottomEdge.Any(v => edgeVerts.Contains(v)))
{
return potentialNeighbor;
}
var leftEdge = potentialNeighbor.GetWorldVerts(potentialNeighbor.GetEdgeVerts(EdgeType.Left));
if (leftEdge.Any(v => edgeVerts.Contains(v)))
{
return potentialNeighbor;
}
var rightEdge = potentialNeighbor.GetWorldVerts(potentialNeighbor.GetEdgeVerts(EdgeType.Right));
if (rightEdge.Any(v => edgeVerts.Contains(v)))
{
return potentialNeighbor;
}
}
}
}
return null;
}
是否有任何对此有经验并愿意分享其他优化查找方法的人？预先感谢。
答案 0 :(得分：0)
由于这篇文章没有收到任何回应，我最终要做的是根据一些基本规则分配同级邻居，然后为非同级邻居找到父级quad，获取其相邻子级，看看他们中是否有人在这个四边形上共享一条边缘
// Get all occurences of the clicked letter and push their positions into array
function letterClicked(id) {
var positionsOfLetter = [];
for (var i = 0; i < randomWord.length; i++) {
if (randomWord[i] == id) {
positionsOfLetter.push(i);
}
}
// Replace each box at position that contains the letter clicked with a box containing the letter clicked
positionsOfLetter.forEach(position => {
$('#' + position).replaceWith($("#" + id));
});
}
这似乎很快起作用，因为所有同级邻居都是直接分配，并且非同级邻居的位置仅限于遍历4个四边形的4个边。这是 HasSharedEdge 方法：
private void AddNeighbors()
{
switch (QuadType)
{
case QuadType.BottomLeft:
// add siblings
AddNeighbor(EdgeType.Top, () => { return GetParent().GetChild(QuadType.TopLeft); });
AddNeighbor(EdgeType.Right, () => { return GetParent().GetChild(QuadType.BottomRight); });
// add non-siblings
AddNeighbor(EdgeType.Bottom, () =>
{
return GetParent().GetNeighbor(EdgeType.Bottom)?.GetChildren()?.FirstOrDefault(c => c != null && HasSharedEdge(EdgeType.Bottom, c));
});
AddNeighbor(EdgeType.Left, () =>
{
return GetParent().GetNeighbor(EdgeType.Left)?.GetChildren()?.FirstOrDefault(c => c != null && HasSharedEdge(EdgeType.Left, c));
});
break;
case QuadType.BottomRight:
// add siblings
AddNeighbor(EdgeType.Top, () => { return GetParent().GetChild(QuadType.TopRight); });
AddNeighbor(EdgeType.Left, () => { return GetParent().GetChild(QuadType.BottomLeft); });
// add non-siblings
AddNeighbor(EdgeType.Bottom, () =>
{
return GetParent().GetNeighbor(EdgeType.Bottom)?.GetChildren()?.FirstOrDefault(c => c != null && HasSharedEdge(EdgeType.Bottom, c));
});
AddNeighbor(EdgeType.Right, () =>
{
return GetParent().GetNeighbor(EdgeType.Right)?.GetChildren()?.FirstOrDefault(c => c != null && HasSharedEdge(EdgeType.Right, c));
});
break;
case QuadType.TopLeft:
// add siblings
AddNeighbor(EdgeType.Bottom, () => { return GetParent().GetChild(QuadType.BottomLeft); });
AddNeighbor(EdgeType.Right, () => { return GetParent().GetChild(QuadType.TopRight); });
// add non-siblings
AddNeighbor(EdgeType.Top, () =>
{
return GetParent().GetNeighbor(EdgeType.Top)?.GetChildren()?.FirstOrDefault(c => c != null && HasSharedEdge(EdgeType.Top, c));
});
AddNeighbor(EdgeType.Left, () =>
{
return GetParent().GetNeighbor(EdgeType.Left)?.GetChildren()?.FirstOrDefault(c => c != null && HasSharedEdge(EdgeType.Left, c));
});
break;
case QuadType.TopRight:
// add siblings
AddNeighbor(EdgeType.Bottom, () => { return GetParent().GetChild(QuadType.BottomRight); });
AddNeighbor(EdgeType.Left, () => { return GetParent().GetChild(QuadType.TopLeft); });
// add non-siblings
AddNeighbor(EdgeType.Top, () =>
{
return GetParent().GetNeighbor(EdgeType.Top)?.GetChildren()?.FirstOrDefault(c => c != null && HasSharedEdge(EdgeType.Top, c));
});
AddNeighbor(EdgeType.Right, () =>
{
return GetParent().GetNeighbor(EdgeType.Right)?.GetChildren()?.FirstOrDefault(c => c != null && HasSharedEdge(EdgeType.Right, c));
});
break;
}
}
也许这可以在将来帮助别人