Fix multiple-strip NiTriStrips loading

components/nif/data.cpp

@@ -98,12 +98,14 @@ void NiTriStripsData::read(NIFStream *nif)
     /*int tris =*/ nif->getUShort();
     // Number of triangle strips
     int numStrips = nif->getUShort();
-    // Number of points in each strip
-    int lengths = nif->getUShort();
+
+    std::vector<unsigned short> lengths;
+    nif->getUShorts(lengths, numStrips);
+
     for (int i = 0; i < numStrips; i++)
     {
         std::vector<unsigned short> strip;
-        nif->getUShorts(strip, lengths);
+        nif->getUShorts(strip, lengths[i]);
         strips.emplace_back(strip);
     }
 }

components/nifbullet/bulletnifloader.cpp

@@ -58,16 +58,25 @@ void fillTriangleMeshWithTransform(btTriangleMesh& mesh, const Nif::NiTriStripsD
 {
     const std::vector<osg::Vec3f> &vertices = data.vertices;
     const std::vector<std::vector<unsigned short>> &strips = data.strips;
-    // Can't make a triangle from less than three vertices. All strips have the same size.
-    if (vertices.empty() || strips.empty() || strips[0].size() < 3)
+    if (vertices.empty() || strips.empty())
         return;
     mesh.preallocateVertices(static_cast<int>(data.vertices.size()));
-    // There are N+2*M vertex indices overall, so we must substract 2*M (N triangles, M strips)
-    mesh.preallocateIndices(static_cast<int>((strips.size()-2) * strips[0].size()));
+    int numTriangles = 0;
+    for (const std::vector<unsigned short>& strip : strips)
+    {
+        // Each strip with N points contains information about N-2 triangles.
+        if (strip.size() >= 3)
+            numTriangles += static_cast<int>(strip.size()-2);
+    }
+    mesh.preallocateIndices(static_cast<int>(numTriangles));
 
     // It's triangulation time. Totally not a NifSkope spell ripoff.
     for (const std::vector<unsigned short>& strip : strips)
     {
+        // Can't make a triangle from less than 3 points.
+        if (strip.size() < 3)
+            continue;
+
         unsigned short a = strip[0], b = strip[0], c = strip[1];
         for (int i = 2; i < static_cast<int>(strip.size()); i++)
         {

components/nifosg/nifloader.cpp

@@ -1081,11 +1081,17 @@ namespace NifOsg
                 const Nif::NiTriStripsData* data = triStrips->data.getPtr();
                 vertexColorsPresent = !data->colors.empty();
                 triCommonToGeometry(geometry, data->vertices, data->normals, data->uvlist, data->colors, boundTextures, triStrips->name);
-                // Can't make a triangle from less than three vertices. All strips have the same size.
-                if (!data->strips.empty() && data->strips[0].size() >= 3)
+                if (!data->strips.empty())
+                {
                     for (const std::vector<unsigned short>& strip : data->strips)
+                    {
+                        // Can't make a triangle from less than three vertices.
+                        if (strip.size() < 3)
+                            continue;
                         geometry->addPrimitiveSet(new osg::DrawElementsUShort(osg::PrimitiveSet::TRIANGLE_STRIP, strip.size(), 
                                                                             (unsigned short*)strip.data()));
+                    }
+                }
             }
 
             // osg::Material properties are handled here for two reasons: