Better description of clustering simplification

src/meshlabplugins/filter_meshing/meshfilter.cpp

@@ -368,14 +368,17 @@ QString ExtraMeshFilterPlugin::filterInfo(ActionIDType filterID) const
 			                                               "<b>4-8 Subdivision</b>"
 			                                               "<br> <i>Luiz Velho, Denis Zorin </i>"
 			                                               "<br>CAGD, volume 18, Issue 5, Pages 397-427. ");
-	case FP_CLUSTERING                         : return tr("Collapse vertices by creating a three dimensional grid enveloping the mesh and discretizes them based on the cells of this grid");
+	case FP_CLUSTERING                         : return tr("Simplify the mesh by clustering vertices; by using a uniform grid over the mesh, the algorithm merges all the vertices in a grid cell into a single vertex. By design this approach removes all small triangles, but also create a number of non-manifold situation.<br> See: <br>"
+			                                               "<br><i>Jarek Rossignac, and Paul Borrel</i>. "
+			                                               "<br><b>Multi-resolution 3D approximations for rendering complex scenes.</b>"
+			                                               "<br>Modeling in computer graphics: methods and applications. Springer, 1993");
 	case FP_QUADRIC_SIMPLIFICATION             : return tr("Simplify a mesh using a quadric based edge-collapse strategy. A variant of the well known Garland and Heckbert simplification algorithm with different weighting schemes to better cope with aspect ration and planar/degenerate quadrics areas."
 							       "<br> See: <br>"
 							       "<i>M. Garland and P. Heckbert.</i> <br>"
 			                                        "<b>Surface Simplification Using Quadric Error Metrics</b> (<a href='http://mgarland.org/papers/quadrics.pdf'>pdf</a>)<br>"
 			                                        "In Proceedings of SIGGRAPH 97.<br/><br/>");
 	case FP_QUADRIC_TEXCOORD_SIMPLIFICATION    : return tr("Simplify a textured mesh using a Quadric based Edge Collapse Strategy preserving UV parametrization. "
-							       "Inspired in the QSLIM surface simplification algorithm "
+							       "Inspired by the QSLIM surface simplification algorithm"
 							       "by Michael Garland, which turned into the industry standard method for mesh simplification."
 							       "<br> See: <br>"
 							       "<i>M. Garland and P. Heckbert.</i> <br>"