[NRRPLT-3964] Prevent segfault in gzcoarse.

Change-Id: I26b3d4ecd663f8b49a7e3789b0e7789351fc6991

tools/gzcoarse.cc

@@ -1180,7 +1180,8 @@ void ConvertGzToGts(const gazebo::common::SubMesh *_subMesh,
     }
     else
     {
-      std::cout << ": Ignoring degenerate facet!\n";
+      // HBP: removed spamming debug that provides little information
+      //std::cout << ": Ignoring degenerate facet!\n";
     }
   }
   gts_surface_merge(_surface, subSurface);
@@ -1233,6 +1234,25 @@ int main(int argc, char **argv)
   {
     const gazebo::common::SubMesh *inSubMesh = inGz->GetSubMesh(s);
 
+    // HBP: VALIDATE COLLADA FILE
+    //
+    // If a dae file does not have the proper TEXCOORD tags in it, the gazebo
+    // collada import will succeed, but the resulting mesh will not have any
+    // texCoord. This will cause a segfault in ExportTextureSource which does
+    // all of its calculations on vertices and then attempts to index into
+    // TexCoord, which will cause a segfault.
+    //
+    // We cannot try to generate an arbitrary mapping between vertices and
+    // the missing texture coordinates, nor can we try to run something like
+    // meshlab or blender since they cannot generate those values to export
+    // unless they were in the original collada to begin with.
+    if (inSubMesh->GetTexCoordCount() == 0)
+    {
+      std::cout << "Collada file does not contain valid texture coordinate "
+                << "mapping. Not simplifying." << std::endl;
+      return -1;
+    }
+
     // GAZEBO to GTS
     GtsSurface *inOutGts;
     inOutGts = gts_surface_new(gts_surface_class(), gts_face_class(),