From 6937e523c29ceff639739523680146f99ccfb874 Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Tue, 20 Jun 2023 20:46:10 -0400
Subject: [PATCH] handle step down greater than part Z height

---
 src/kiri-mode/cam/ops.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/kiri-mode/cam/ops.js b/src/kiri-mode/cam/ops.js
index caad2b82..59648bb9 100644
--- a/src/kiri-mode/cam/ops.js
+++ b/src/kiri-mode/cam/ops.js
@@ -577,6 +577,7 @@ class OpOutline extends CamOp {
         if (zThru) {
             let last = slices[slices.length-1];
             for (let zneg of base.util.lerp(0, zThru, op.down)) {
+                if (!last) continue;
                 let add = last.clone(true);
                 add.tops.forEach(top => top.poly.setZ(add.z));
                 add.shadow = last.shadow.clone(true);