added data-dependent epsilon calculation

MeshLib/MeshGenerators/LayeredVolume.cpp

@@ -32,10 +32,9 @@
 
 
 const double LayeredVolume::_invalid_value = -9999;
-const double LayeredVolume::_elevation_epsilon = 0.0001;
 
 LayeredVolume::LayeredVolume()
-: _mesh(nullptr)
+: _elevation_epsilon(0.0001), _mesh(nullptr)
 {
 }
 
@@ -60,6 +59,8 @@ bool LayeredVolume::createGeoVolumes(const MeshLib::Mesh &mesh, const std::vecto
 	if (mesh.getDimension() != 2)
 		return false;
 
+	_elevation_epsilon = calcEpsilon(*rasters.back(), *rasters[0]);
+
 	// remove line elements, only tri + quad remain
 	MeshLib::ElementExtraction ex(mesh);
 	ex.searchByElementType(MeshElemType::LINE);
@@ -204,6 +205,13 @@ bool LayeredVolume::exportToGeometry(GeoLib::GEOObjects &geo_objects) const
 	return true;
 }
 
+double LayeredVolume::calcEpsilon(const GeoLib::Raster &high, const GeoLib::Raster &low)
+{
+	const double max (*std::max_element(high.begin(), high.end()));
+	const double min (*std::min_element(high.begin(), high.end()));
+	return ((max-min)*1e-07);
+}
+
 bool LayeredVolume::allRastersExist(const std::vector<std::string> &raster_paths) const
 {
 	for (auto raster = raster_paths.begin(); raster != raster_paths.end(); ++raster)

MeshLib/MeshGenerators/LayeredVolume.h

@@ -77,6 +77,9 @@ private:
 	/// Removes duplicate 2D elements (possible due to outcroppings)
 	void removeCongruentElements(std::size_t nLayers, std::size_t nElementsPerLayer);
 
+	/// Calculates a data-dependent epsilon value
+	double calcEpsilon(const GeoLib::Raster &high, const GeoLib::Raster &low);
+
 	/// Checks if all raster files actually exist
 	bool allRastersExist(const std::vector<std::string> &raster_paths) const;
 
@@ -84,7 +87,7 @@ private:
 	void cleanUpOnError();
 
 	static const double _invalid_value;
-	static const double _elevation_epsilon;
+	double _elevation_epsilon;
 	std::vector<MeshLib::Node*> _nodes;
 	std::vector<MeshLib::Element*> _elements;
 	std::vector<MeshLib::Node> _attribute_points;