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Merged
mahach666 merged 1 commit into from
Nov 12, 2026
Merged

Clash detection: visit each pair of overlapping selections once #152

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44 changes: 39 additions & 5 deletions src/NwcIO/Model/Clash/NwcClashDetector.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -64,7 +64,18 @@ private static void RunCore(
string modelName)
{
bool sameSelection = ReferenceEquals(meshesA, meshesB) ||
(meshesA.Count == meshesB.Count && meshesA.Count > 0 && ReferenceEquals(meshesA[0], meshesB[0]));
meshesA.SequenceEqual(meshesB, ReferenceEqualityComparer.Instance);
Dictionary<NwcMesh, int>? firstIndexA = null;
HashSet<NwcMesh>? meshesInB = null;
if (!sameSelection)
{
firstIndexA = new Dictionary<NwcMesh, int>(ReferenceEqualityComparer.Instance);
for (int i = 0; i < meshesA.Count; i++)
{
firstIndexA.TryAdd(meshesA[i], i);
}
meshesInB = new HashSet<NwcMesh>(meshesB, ReferenceEqualityComparer.Instance);
}

bool ignoreSameLayer = test.Rules.Any(r => r.Enabled && r.RuleType == NwcClashRuleType.IgnoreSameLayer);
bool ignoreSameGroup = test.Rules.Any(r => r.Enabled && r.RuleType == NwcClashRuleType.IgnoreSameGroup);
Expand All @@ -74,12 +85,17 @@ private static void RunCore(
var meshA = meshesA[i];
var boxA = meshA.GetWorldBoundingBox();
if (boxA.IsEmpty) continue;
bool canVisitReverse = !sameSelection && meshesInB!.Contains(meshA);

int startJ = sameSelection ? i + 1 : 0;
for (int j = startJ; j < meshesB.Count; j++)
for (var j = sameSelection ? i + 1 : 0; j < meshesB.Count; j++)
{
var meshB = meshesB[j];
if (ReferenceEquals(meshA, meshB) || meshA.Id == meshB.Id) continue;
// The reverse pair was already visited from the earlier mesh in A.
if (canVisitReverse && firstIndexA!.TryGetValue(meshB, out int firstIndex) && firstIndex < i)
{
continue;
}

var boxB = meshB.GetWorldBoundingBox();
if (boxB.IsEmpty) continue;
Expand Down Expand Up @@ -149,7 +165,19 @@ private static void RunCoreMultiModel(
List<(NwcMesh Mesh, string ModelName, string? Layer)> itemsB,
NwcClashTest test)
{
bool sameSelection = itemsA.Select(item => item.Mesh).SequenceEqual(itemsB.Select(item => item.Mesh));
bool sameSelection = itemsA.Select(item => item.Mesh)
.SequenceEqual(itemsB.Select(item => item.Mesh), ReferenceEqualityComparer.Instance);
Dictionary<NwcMesh, int>? firstIndexA = null;
HashSet<NwcMesh>? meshesInB = null;
if (!sameSelection)
{
firstIndexA = new Dictionary<NwcMesh, int>(ReferenceEqualityComparer.Instance);
for (int i = 0; i < itemsA.Count; i++)
{
firstIndexA.TryAdd(itemsA[i].Mesh, i);
}
meshesInB = new HashSet<NwcMesh>(itemsB.Select(item => item.Mesh), ReferenceEqualityComparer.Instance);
}
bool ignoreSameFile = test.Rules.Any(r => r.Enabled && r.RuleType == NwcClashRuleType.IgnoreSameFile);
bool ignoreSameLayer = test.Rules.Any(r => r.Enabled && r.RuleType == NwcClashRuleType.IgnoreSameLayer);

Expand All @@ -158,11 +186,17 @@ private static void RunCoreMultiModel(
var itemA = itemsA[i];
var boxA = itemA.Mesh.GetWorldBoundingBox();
if (boxA.IsEmpty) continue;
bool canVisitReverse = !sameSelection && meshesInB!.Contains(itemA.Mesh);

for (int j = sameSelection ? i + 1 : 0; j < itemsB.Count; j++)
for (var j = sameSelection ? i + 1 : 0; j < itemsB.Count; j++)
{
var itemB = itemsB[j];
if (ReferenceEquals(itemA.Mesh, itemB.Mesh)) continue;
// Mesh IDs can repeat across models; only references identify pairs.
if (canVisitReverse && firstIndexA!.TryGetValue(itemB.Mesh, out int firstIndex) && firstIndex < i)
{
continue;
}

if (ignoreSameFile && string.Equals(itemA.ModelName, itemB.ModelName, StringComparison.OrdinalIgnoreCase))
{
Expand Down
54 changes: 54 additions & 0 deletions tests/NwcIO.Tests/ClashDetectiveTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -76,6 +76,60 @@ public void MeshClashDetectionIdentifiesInterpenetratingElements()
Assert.NotNull(clash.Item2.IfcGuid);
}

[Theory]
[InlineData(false, false)]
[InlineData(false, true)]
[InlineData(true, false)]
[InlineData(true, true)]
public void ClashDetection_OverlappingSelectionsReportsEachPairOnce(bool federated, bool includeSharedPair)
{
var mesh1 = CreateBoxMesh(1, new(0, 0, 0), new(2, 2, 2));
var mesh2 = CreateBoxMesh(2, new(1.5, 0.5, 0.5), new(3.5, 1.5, 1.5));
var mesh3 = CreateBoxMesh(3, new(3, 0, 0), new(5, 2, 2));
var builder = new NwcDocumentBuilder().SetFileInfo("Architecture.nwc")
.AddMesh(mesh1)
.AddMesh(mesh2);
if (!federated)
{
builder.AddMesh(mesh3);
}
var doc = builder.Build();
var test = new NwcClashTest("Overlapping selections");
test.SelectionA.ExplicitNodeIds.AddRange([1, 2]);
test.SelectionB.ExplicitNodeIds.AddRange(includeSharedPair ? [1, 2, 3] : [1, 3]);

if (federated)
{
var otherDoc = new NwcDocumentBuilder().SetFileInfo("MEP.nwc").AddMesh(mesh3).Build();
NwcClashDetector.Run(NwcAssembly.Create("Federated", doc, otherDoc), test);
}
else
{
doc.RunClashDetection(test);
}

var pairs = test.Results.Select(clash => (
Math.Min(clash.Item1.Mesh!.Id, clash.Item2.Mesh!.Id),
Math.Max(clash.Item1.Mesh!.Id, clash.Item2.Mesh!.Id))).OrderBy(pair => pair.Item1).ToArray();
Assert.Equal([(1, 2), (2, 3)], pairs);
}

[Fact]
public void AssemblyClashDetection_AllVsAllPreservesPairsWithRepeatedMeshIds()
{
var architecture = new NwcDocumentBuilder().SetFileInfo("Architecture.nwc")
.AddMesh(CreateBoxMesh(1, new(0, 0, 0), new(2, 2, 2)))
.Build();
var mep = new NwcDocumentBuilder().SetFileInfo("MEP.nwc")
.AddMesh(CreateBoxMesh(1, new(1, 1, 1), new(3, 3, 3)))
.Build();

var test = NwcAssembly.Create("Federated", architecture, mep).RunClashDetection();

var clash = Assert.Single(test.Results);
Assert.NotEqual(clash.Item1.ModelName, clash.Item2.ModelName);
}

[Theory]
[InlineData(false, false, 0)]
[InlineData(true, false, 2)]
Expand Down
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