diff --git a/src/main/mesh.js b/src/main/mesh.js
index 6765cc2e..f3d015f8 100644
--- a/src/main/mesh.js
+++ b/src/main/mesh.js
@@ -167,21 +167,27 @@ function ui_build() {
             return h.bind(selectlist, []);
         }
         // map selection to divs
-        let h_grp = s_grp.map(g => h.div([
-                h.button({ _: `group`, title: g.id, xclass: [ "group" ], }),
+        let g_pos = util.average(s_grp.map(g => g.object.position));
+        let g_rot = util.average(s_grp.map(g => g.object.rotation));
+        let g_id = s_grp.map(g => g.id).join(' ');
+        let h_grp = [h.div([
+                h.button({ _: `group`, title: g_id, xclass: [ "group" ], }),
                 grid(
-                    util.extract(g.object.position, map),
-                    util.extract(g.object.rotation, map) )
-            ]));
-        let h_mdl = s_mdl.map(m => h.div([
-                h.button({ _: `model`, title: m.id, xclass: [ "model" ], }),
+                    util.extract(g_pos, map),
+                    util.extract(g_rot, map) )
+            ])];
+        let m_pos = util.average(s_mdl.map(m => m.object.position));
+        let m_rot = util.average(s_mdl.map(m => m.object.rotation));
+        let m_id = s_mdl.map(m => m.id).join(' ');
+        let h_mdl = [h.div([
+                h.button({ _: `model`, title: m_id, xclass: [ "model" ], }),
                 grid(
-                    util.extract(m.object.position, map),
-                    util.extract(m.object.rotation, map) )
-            ]));
+                    util.extract(m_pos, map),
+                    util.extract(m_rot, map) )
+            ])];
         let bounds = util.bounds(s_mdl);
         let h_bnd = [h.div([
-                h.button({ _: `box`, title: s_mdl[0].id, xclass: [ "box" ], }),
+                h.button({ _: `box`, title: m_id, xclass: [ "box" ], }),
                 grid(
                     util.extract(bounds.min, map),
                     util.extract(bounds.max, map),
@@ -189,7 +195,7 @@ function ui_build() {
                 )
             ])];
         let h_ara = [h.div([
-                h.button({ _: `area`, title: s_mdl[0].id, xclass: [ "area" ], }),
+                h.button({ _: `area`, title: m_id, xclass: [ "area" ], }),
                 grid(
                     util.extract(bounds.center, map),
                     util.extract(bounds.size, map),
diff --git a/src/mesh/api.js b/src/mesh/api.js
index 4a02332d..672b0661 100644
--- a/src/mesh/api.js
+++ b/src/mesh/api.js
@@ -96,7 +96,7 @@ let selection = {
     },
 
     clear() {
-        for (let s of selected) {
+        for (let s of selection.list()) {
             selection.remove(s);
         }
     },
@@ -362,6 +362,20 @@ let util = mesh.util = {
             array.push(v);
         }
         return array;
+    },
+
+    average(array, opt = {}) {
+        let fields = opt.fields || ['x', 'y', 'z'];
+        let avg = {};
+        for (let e of array) {
+            for (let f of fields) {
+                avg[f] = (avg[f] || 0) + e[f];
+            }
+        }
+        for (let f of fields) {
+            avg[f] = (avg[f] || 0)  / array.length;
+        }
+        return avg;
     }
 };
 
diff --git a/src/mesh/model.js b/src/mesh/model.js
index deef7992..db887076 100644
--- a/src/mesh/model.js
+++ b/src/mesh/model.js
@@ -127,6 +127,18 @@ mesh.model = class MeshModel extends mesh.object {
         this._group = gv;
     }
 
+    get attributes() {
+        return this.mesh.geometry.attributes;
+    }
+
+    get vertices() {
+        return this.attributes.vertices.count;
+    }
+
+    get faces() {
+        return this.vertices / 3;
+    }
+
     opacity(ov) {
         let mat = this.mesh.material;
         if (ov === undefined) {