diff --git a/src/main/mesh.js b/src/main/mesh.js
index d97f8d06..0bb37b31 100644
--- a/src/main/mesh.js
+++ b/src/main/mesh.js
@@ -5,6 +5,7 @@
 (function() {
 
 let broker = gapp.broker;
+let call = broker.send;
 
 function init() {
     let moto = self.moto,
@@ -36,22 +37,78 @@ function init() {
     });
     space.view.setZoom(zoomrev, zoomspd);
 
-    // trigger space event binding
-    broker.send.space_init({ space, platform });
-
     // start worker
     moto.client.start(`/code/mesh_work?${gapp.version}`);
 
-    // set app version
-    $h('app-name', "Mesh:Tool");
-    $h('app-vers', gapp.version);
+    // trigger space event binding
+    call.space_init({ space, platform });
+
+    // trigger ui building
+    call.ui_build();
 
     // hide loading curtain
     $d('curtain','none');
 }
 
+function ui_build() {
+    // set app version
+    $h('app-name', "Mesh:Tool");
+    $h('app-vers', gapp.version);
+
+    let bound = h.bind($('app-body'), [
+        h.div({id: 'grouplist'})
+    ]);
+
+    let { grouplist } = bound;
+    let api = mesh.api;
+
+    let maker = {
+        update() {
+            clearTimeout(maker.timer);
+            maker.timer = setTimeout(maker.do, 10);
+        },
+        do() {
+            let groups = api.group.list()
+                // map groups to divs
+                .map(g => h.div([
+                    h.button({
+                        _: g.id,
+                        class: [
+                            "group",
+                            api.selection.contains(g) ? 'selected' : undefined
+                        ],
+                        onclick() { api.selection.toggle(g); }
+                    }),
+                    h.div({ class: "vsep" }),
+                    h.div({ class: "models"},
+                        // map models to buttons
+                        g.models.map(m => h.button({
+                            _: m.id,
+                            class: api.selection.contains(m) ? [ 'selected' ] : [],
+                            onclick() { api.selection.toggle(m); }
+                        }))
+                    )
+                ]));
+            h.bind(grouplist, groups);
+        }
+    };
+
+    function update(object, topic) {
+        console.log({update: object, topic});
+    }
+
+    // listen for api calls
+    broker.listeners({
+        model_add: maker.update,
+        group_add: maker.update,
+        model_remove: maker.update,
+        group_remove: maker.update,
+        selection_update: maker.update,
+    })
+}
+
 // add space event bindings
-broker.subscribe('space_init', data => {
+function space_init(data) {
     let { space, platform } = data;
     let platcolor = 0x00ff00;
     let api = mesh.api;
@@ -64,7 +121,7 @@ broker.subscribe('space_init', data => {
             platform.setColor(platcolor);
             load.File.load([...evt.dataTransfer.files])
                 .then(data => {
-                    broker.send.space_load(data);
+                    call.space_load(data);
                 })
                 .catch(error => {
                     dbug.error(error);
@@ -127,7 +184,7 @@ broker.subscribe('space_init', data => {
                             m.debug();
                         }
                     } else {
-                        broker.send.space_debug();
+                        call.space_debug();
                     }
                     break;
                 case 'Escape':
@@ -199,20 +256,19 @@ broker.subscribe('space_init', data => {
             return api.objects().length > 0;
         }
     });
-
-});
+}
 
 // add object loader
-broker.subscribe('space_load', data => {
+function space_load(data) {
     mesh.api.group.new(data.flat().map(el => new mesh.model(el)))
         .centerModels()
         .centerXY()
         .floor()
         .focus();
-});
+}
 
 // on debug key press
-broker.subscribe('space_debug', () => {
+function space_debug() {
     for (let g of mesh.api.group.list()) {
         let { center, size } = g.bounds();
         console.group(g.id);
@@ -230,6 +286,14 @@ broker.subscribe('space_debug', () => {
         console.groupEnd();
     }
     moto.client.fn.debug();
+}
+
+// bind functions to topics
+broker.listeners({
+    ui_build,
+    space_init,
+    space_load,
+    space_debug,
 });
 
 // remove version cache bust from url
diff --git a/src/mesh/api.js b/src/mesh/api.js
index 2a0db761..f3b856ea 100644
--- a/src/mesh/api.js
+++ b/src/mesh/api.js
@@ -50,6 +50,10 @@ let selection = {
         return mdl;
     },
 
+    contains(object) {
+        return selected.contains(object);
+    },
+
     // @param group {MeshObject[]}
     set(objects) {
         selected = objects;
@@ -82,6 +86,9 @@ let selection = {
         for (let group of groups) {
             group.material(mesh.material.unselected);
         }
+        // prevent selection of model and its group
+        let mgsel = selected.filter(s => s instanceof mesh.model).map(m => m.group);
+        selected = selected.filter(sel => !mgsel.contains(sel));
         for (let object of selected) {
             object.material(mesh.material.selected);
         }
diff --git a/src/mesh/group.js b/src/mesh/group.js
index 30fa25e6..1b879097 100644
--- a/src/mesh/group.js
+++ b/src/mesh/group.js
@@ -8,6 +8,7 @@ gapp.register("mesh.group", [
     "add.array",    // dep: add.array
     "add.three",    // dep: add.three
     "moto.license", // dep: moto.license
+    "moto.broker",  // dep: moto.broker
     "mesh.object",  // dep: mesh.object
     "mesh.model",   // dep: mesh.model
     "mesh.api",     // dep: mesh.api
@@ -16,12 +17,15 @@ gapp.register("mesh.group", [
 let mesh = self.mesh = self.mesh || {};
 if (mesh.group) return;
 
+let broker = gapp.broker;
+let call = broker.send;
+
 let space = moto.Space;
 let worker = moto.client.fn;
 
 mesh.group = class MeshGroup extends mesh.object {
 
-    // @param group {mesh.model[]}
+    // @param group {MeshModel[]}
     constructor(models = []) {
         super();
         this.group = new THREE.Group();
@@ -45,6 +49,7 @@ mesh.group = class MeshGroup extends mesh.object {
         this.models.addOnce(model);
         this.group.add(model.mesh);
         space.update();
+        call.model_add({model, group:this});
         worker.group_add({id: this.id, model:model.id});
         return this;
     }
@@ -61,6 +66,8 @@ mesh.group = class MeshGroup extends mesh.object {
         model.group = undefined;
         this.models.remove(model);
         this.group.remove(model.mesh);
+        // create message for listeners
+        call.model_remove({model, group:this});
         // trigger sync with worker
         worker.group_remove({id: this.id, model:model.id});
         model.remove(true);
diff --git a/src/mesh/work.js b/src/mesh/work.js
index 59ef1477..4a8c97fd 100644
--- a/src/mesh/work.js
+++ b/src/mesh/work.js
@@ -18,7 +18,7 @@ gapp.finalize("mesh.work", [
 ]);
 
 // compensation for space/world/platform rotation
-let space_rotation = new THREE.Matrix4().makeRotationX(Math.PI / 2);
+let core_matrix = new THREE.Matrix4().makeRotationX(Math.PI / 2);
 
 let { client, worker } = moto;
 let cache = {};
@@ -38,14 +38,14 @@ let model = {
         let geo = new THREE.BufferGeometry();
         geo.setAttribute('position', new THREE.BufferAttribute(vertices, 3));
         geo.computeVertexNormals();
-        cacheUpdate(id, { name, geo });
+        cacheUpdate(id, { name, geo, matrix: core_matrix.clone() });
     },
 
     debug(data) {
         let { matrix, id } = data;
         let rec = cache[id];
         let geo = rec.geo.clone();
-        let m4 = space_rotation.clone().multiply( new THREE.Matrix4().fromArray(matrix) );
+        let m4 = core_matrix.clone().multiply( new THREE.Matrix4().fromArray(matrix) );
         geo.applyMatrix4(m4);
         // for debugging state / matrix ops
         return geo.attributes.position.array;
@@ -59,11 +59,6 @@ let group = {
 
     remove(data) {
         let { id, model } = data;
-    },
-
-    create(data) {
-        let { id, type } = data;
-        cache[id] = { id, type };
     }
 };
 
@@ -78,23 +73,23 @@ let object = {
     },
 
     move(data) {
-        let { id, type, x, y, z } = data;
+        let { id, x, y, z } = data;
     },
 
     position(data) {
-        let { id, type, x, y, z } = data;
+        let { id, x, y, z } = data;
     },
 
     rotate(data) {
-        let { id, type, x, y, z } = data;
+        let { id, x, y, z } = data;
     },
 
     rotation(data) {
-        let { id, type, x, y, z } = data;
+        let { id, x, y, z } = data;
     },
 
     qrotation(data) {
-        let { id, type, w, x, y, z } = data;
+        let { id, w, x, y, z } = data;
     }
 };
 
diff --git a/src/moto/broker.js b/src/moto/broker.js
index ff58eef3..8abd2c29 100644
--- a/src/moto/broker.js
+++ b/src/moto/broker.js
@@ -23,6 +23,20 @@ gapp.broker = new class Broker {
         return Object.keys(this.topics);
     }
 
+    // create subscriptions for all functions in an object
+    // a complement wrapObject on the subscription side
+    listeners(object, root) {
+        for (let [key, fn] of Object.entries(object)) {
+            if (typeof fn === 'function') {
+                key = root ? `${root}_${key}` : key;
+                this.subscribe(key, fn);
+            }
+        }
+    }
+
+    // attach function to a topic
+    // creates topic if new topic
+    // creates a send function if new topic
     subscribe(topic, listener) {
         if (Array.isArray(topic)) {
             for (let t of topic) {
diff --git a/src/moto/webui.js b/src/moto/webui.js
index 4c9671f7..9f92ad5b 100644
--- a/src/moto/webui.js
+++ b/src/moto/webui.js
@@ -58,8 +58,9 @@ function build(data, context) {
             func[key] = val;
             elid = elid || `_${nextid++}`;
         } else if (tov === 'object') {
-            html.push(` ${key}="${val.join(' ')}"`);
-        } else {
+            if (val.length)
+            html.push(` ${key}="${val.filter(v => v !== undefined).join(' ')}"`);
+        } else if (tov !== 'undefined') {
             html.push(` ${key}="${val}"`);
         }
     }
diff --git a/web/mesh/index.css b/web/mesh/index.css
index 07b87bc6..02a2a349 100644
--- a/web/mesh/index.css
+++ b/web/mesh/index.css
@@ -140,3 +140,35 @@ body, div {
     margin-right: -14px !important;
     margin-bottom: -14px !important;
 }
+
+#grouplist {
+    position: absolute;
+    margin: 3px 3px 0 0;
+    right: 0;
+    top: 0;
+}
+
+#grouplist, #grouplist div {
+    flex-direction: column;
+    background-color: transparent;
+}
+
+#grouplist > div {
+    border: 1px solid gray;
+    border-radius: 3px;
+    padding: 3px;
+}
+
+#grouplist .models button {
+    margin-top: 1px;
+}
+
+#grouplist .selected {
+    background-color: rgba(0,255,0,0.75)
+}
+
+#grouplist .vsep {
+    height: 1px;
+    margin: 2px 0 1px 0;
+    background-color: gray;
+}