diff --git a/src/viewport-three/viewport-host.ts b/src/viewport-three/viewport-host.ts
index 2a7f6eb7..deb05b7c 100644
--- a/src/viewport-three/viewport-host.ts
+++ b/src/viewport-three/viewport-host.ts
@@ -632,6 +632,14 @@ const TERRAIN_GRID_RESIZE_ARROW_HEAD_RADIUS = 0.34;
 const TERRAIN_GRID_RESIZE_ARROW_HEAD_OUTLINE_RADIUS = 0.48;
 const TERRAIN_GRID_RESIZE_ARROW_HEAD_LENGTH = 0.76;
 const TERRAIN_GRID_RESIZE_ARROW_HEAD_OUTLINE_LENGTH = 0.94;
+const TERRAIN_GRID_RESIZE_ARROW_PICK_SHAFT_RADIUS = 0.32;
+const TERRAIN_GRID_RESIZE_ARROW_PICK_HEAD_RADIUS = 0.62;
+const TERRAIN_GRID_RESIZE_SIDES: TerrainGridResizeSide[] = [
+  "east",
+  "west",
+  "north",
+  "south"
+];
 const BOX_CREATE_PREVIEW_FILL = 0x89b6ff;
 const BOX_CREATE_PREVIEW_EDGE = 0xf3be8f;
 const PLACEMENT_PREVIEW_COLOR_HEX = "#89b6ff";