diff --git a/app.js b/app.js
index f65154b4..1b2a8fb7 100644
--- a/app.js
+++ b/app.js
@@ -290,6 +290,7 @@ const script = {
         "ext/pngjs",
         "license",
         "ext/clip2",
+        "ext/earcut",
         "add/array",
         "add/three",
         "add/class",
diff --git a/src/kiri/codec.js b/src/kiri/codec.js
index e69214d6..a9d19d3d 100644
--- a/src/kiri/codec.js
+++ b/src/kiri/codec.js
@@ -16,6 +16,9 @@
     };
 
     function allocFloat32Array(len) {
+        if (Array.isArray(len)) {
+            return new Float32Array(len);
+        }
         return new Float32Array(len);
     }
 
@@ -121,7 +124,7 @@
             data: Object.values(this.layers).map(layer => { return {
                 polys: encode(layer.polys, state),
                 lines: encodePointArray(layer.lines, state),
-                faces: encodePointArray(layer.faces, state),
+                faces: codec.allocFloat32Array(layer.faces),
                 color: layer.color
             } })
         };
@@ -134,7 +137,7 @@
             render.layers[v.layers[i]] = {
                 polys: decode(v.data[i].polys, state),
                 lines: decodePointArray(v.data[i].lines),
-                faces: decodePointArray(v.data[i].faces),
+                faces: v.data[i].faces,
                 color: v.data[i].color
             };
         }
diff --git a/src/kiri/render.js b/src/kiri/render.js
index ed9a5ee5..ce5b6a91 100644
--- a/src/kiri/render.js
+++ b/src/kiri/render.js
@@ -3,18 +3,29 @@
 "use strict";
 
 (function() {
+    const KIRI = self.kiri, BASE = self.base, POLY = BASE.polygons;
+
     class Render {
         constructor() {
             this.layers = {};
         }
 
-        setLayer(layer, color) {
+        setLayer(layer, colors) {
             let layers = this.layers;
+            if (typeof(colors) === 'number') {
+                colors = {
+                    line: color,
+                    face: color
+                };
+            }
             this.current = layers[layer] = layers[layer] || {
                 lines: [],
                 polys: [],
                 faces: [],
-                color: color || 0
+                color: colors || {
+                    line: 0,
+                    face: 0
+                }
             };
             return this;
         }
@@ -44,6 +55,33 @@
             }
             return this;
         }
+
+        addFlat(polys, options) {
+            let opts = options || {};
+            let offset = opts.offset || 1;
+            if (Array.isArray(polys)) {
+                polys = POLY.flatten(polys, [], true);
+            } else {
+                polys = POLY.flatten([polys], [], true);
+            }
+            if (!polys.length) {
+                return;
+            }
+            const z = polys[0].getZ(), faces = this.current.faces;
+            polys.forEach(poly => {
+                let exp = [];
+                POLY.offset([poly],  offset/2, { z, outs: exp, flat: true });
+                POLY.offset([poly], -offset/2, { z, outs: exp, flat: true });
+                if (opts.outline) {
+                    this.addPolys(exp.clone());
+                }
+                POLY.nest(exp).forEach((poly,i) => {
+                    poly.earcut().forEach(ep => {
+                        ep.forEachPoint(p => { faces.push(p.x, p.y, p.z) });
+                    });
+                });
+            });
+        }
     }
 
     self.kiri.Render = Render;
diff --git a/src/mode/cam/client.js b/src/mode/cam/client.js
index db617d89..a84bc5fe 100644
--- a/src/mode/cam/client.js
+++ b/src/mode/cam/client.js
@@ -46,18 +46,39 @@
         }
 
         for (const [layer, data] of Object.entries(render.layers)) {
-            const mat = new THREE.LineBasicMaterial({ color: data.color });
-            const geo = new THREE.Geometry(), vertices = geo.vertices;
-            const polys = data.polys;
-            for (let i=0, il=polys.length; i<il; i++) {
-                addPoly(vertices, polys[i]);
+            const { polys, lines, faces } = data;
+            if (polys.length || lines.length) {
+                const mat = new THREE.LineBasicMaterial({ color: data.color.line });
+                const geo = new THREE.Geometry(), vert = geo.vertices;
+                for (let i=0, il=polys.length; i<il; i++) {
+                    addPoly(vert, polys[i]);
+                }
+                for (let i=0, il=lines.length; i<il; i++) {
+                    const p = lines[i];
+                    vert.push(new THREE.Vector3(p.x, p.y, p.z));
+                }
+                if (vert.length) {
+                    group.add(new THREE.LineSegments(geo, mat));
+                }
             }
-            const lines = data.lines;
-            for (let i=0, il=lines.length; i<il; i++) {
-                const p = lines[i];
-                vertices.push(new THREE.Vector3(p.x, p.y, p.z));
+            if (faces.length) {
+                const mat = new THREE.MeshPhongMaterial({
+                    transparent: true,
+                    shininess: 100,
+                    specular: 0x181818,
+                    opacity: 1,
+                    color: data.color.face,
+                    side: THREE.DoubleSide
+                });
+                const geo = new THREE.BufferGeometry();
+                geo.setAttribute('position', new THREE.BufferAttribute(faces, 3));
+                geo.computeFaceNormals();
+                geo.computeVertexNormals();
+                const mesh = new THREE.Mesh(geo, mat);
+                mesh.castShadow = true;
+                mesh.receiveShadow = true;
+                group.add(mesh);
             }
-            group.add(new THREE.LineSegments(geo, mat));
         }
 
         slice.view.add(group);
diff --git a/src/mode/cam/slice.js b/src/mode/cam/slice.js
index 538ddbb3..af8aa5c7 100644
--- a/src/mode/cam/slice.js
+++ b/src/mode/cam/slice.js
@@ -123,7 +123,8 @@
             tslices.push(data.slice);
             // sliceAll.push(data.slice);
             // data.slice.output()
-            //     .setLayer("debug", 0xff0000)
+            //     .setLayer("debug", {face: 0xff0000, line: 0})
+            //     // .addFlat(POLY.setZ(tshadow.clone(true), data.z), {offset: 1, outline: true});
             //     .addPolys(POLY.setZ(tshadow.clone(true), data.z));
             updateOp(index, total);
         }, genso: true });