diff --git a/src2/geo/polygon.js b/src2/geo/polygon.js
index b6e49f07..6e665522 100644
--- a/src2/geo/polygon.js
+++ b/src2/geo/polygon.js
@@ -997,6 +997,23 @@ export class Polygon {
         return this.z !== undefined ? this.z : this.points[i || 0]?.z || 0;
     }
 
+    minZ() {
+        return Math.min(...this.points.map(p => p.z));
+    }
+
+    avgZ() {
+        return [...this.points.map(p => p.z)].reduce((a,v) => a+v) / this.points.length;
+    }
+
+    /**
+     * @param {*} z value target
+     * @param {*} epsilon allowed Z variance
+     * @returns {boolean} true if all points Z within epsilon of value
+     */
+    onZ(z, epsilon = 10e-4) {
+        return Math.max(...this.points.map(p => Math.abs(z - p.z))) < epsilon;
+    }
+
     /**
      */
     render(layer, color, recursive, open) {
diff --git a/src2/kiri-mode/cam/driver-fe.js b/src2/kiri-mode/cam/driver-fe.js
index e5cf20c7..d78f0ac1 100644
--- a/src2/kiri-mode/cam/driver-fe.js
+++ b/src2/kiri-mode/cam/driver-fe.js
@@ -45,7 +45,6 @@ function traces(ondone, single) {
     const settings = api.conf.get();
     const widgets = api.widgets.map();
     api.client.send("cam_traces", { settings, single }, output => {
-        console.log({ output });
         const ids = [];
         codec.decode(output).forEach(rec => {
             ids.push(rec.id);