diff --git a/src/main/mesh.js b/src/main/mesh.js
index 0bb37b31..98803a34 100644
--- a/src/main/mesh.js
+++ b/src/main/mesh.js
@@ -233,15 +233,16 @@ function space_init(data) {
             let model = int && int.object.model ? int.object.model : undefined;
             if (model) {
                 let group = model.group;
+                let { ctrlKey, metaKey, shiftKey } = event;
                 // lay flat with meta or ctrl clicking a selected face
-                if ((event.ctrlKey || event.metaKey)) {
+                if ((ctrlKey || metaKey)) {
                     let q = new THREE.Quaternion();
                     // find intersecting point, look "up" on Z and rotate to face that
                     q.setFromUnitVectors(int.face.normal, new THREE.Vector3(0,0,-1));
                     group.qrotation(q);
                     group.floor();
                 } else {
-                    selection.toggle(model.group);
+                    selection.toggle(shiftKey ? model.group : model);
                 }
             }
         } else {
@@ -250,7 +251,7 @@ function space_init(data) {
     });
 
     space.mouse.onDrag((delta, offset, up = false) => {
-        if (delta) {
+        if (delta && delta.event.shiftKey) {
             selection.move(delta.x, delta.y, 0);
         } else {
             return api.objects().length > 0;
diff --git a/src/mesh/api.js b/src/mesh/api.js
index f3b856ea..6f7c0b52 100644
--- a/src/mesh/api.js
+++ b/src/mesh/api.js
@@ -62,21 +62,39 @@ let selection = {
 
     // @param group {MeshObject}
     add(object) {
+        // pendantic code necessary to minimize re-entrant api calls
+        if (object.models) {
+            // if group, remove discrete selected members
+            for (let m of object.models) {
+                if (selected.contains(m)) {
+                    selection.remove(m);
+                }
+            }
+        } else {
+            // if model, remove selcted group
+            if (selected.contains(object.group)) {
+                selection.remove(object.group);
+            }
+        }
         selected.addOnce(object);
         selection.update();
     },
 
-    toggle(object) {
-        selected.remove(object) || selected.addOnce(object);
-        selection.update();
-    },
-
     // @param group {MeshObject}
     remove(object) {
         selected.remove(object);
         selection.update();
     },
 
+    // @param group {MeshObject}
+    toggle(object) {
+        if (selected.contains(object)) {
+            selection.remove(object);
+        } else {
+            selection.add(object);
+        }
+    },
+
     clear() {
         selected = [];
         selection.update();
diff --git a/src/moto/space.js b/src/moto/space.js
index 1d0655e2..b918d51f 100644
--- a/src/moto/space.js
+++ b/src/moto/space.js
@@ -875,7 +875,11 @@
                 let delta = mouseDragPoint.clone().sub(int[0].point);
                 let offset = mouseDragStart.clone().sub(int[0].point);
                 mouseDragPoint = int[0].point;
-                mouseDrag({x: -delta.x, y: delta.z}, offset.multiplyVectors(offset, trackDelta));
+                mouseDrag({
+                    x: -delta.x,
+                    y: delta.z,
+                    event
+                }, offset.multiplyVectors(offset, trackDelta));
                 requestRefresh();
             }
         }