slab panel

packages/core/src/systems/wall/wall-system.tsx

@@ -151,6 +151,7 @@ export function generateExtrudedWall(
 
   const wallStart: Point2D = { x: wallNode.start[0], y: wallNode.start[1] }
   const wallEnd: Point2D = { x: wallNode.end[0], y: wallNode.end[1] }
+  // Wall height is adjusted by slab elevation (positive reduces, negative increases)
   const height = (wallNode.height ?? 2.5) - slabElevation
   const thickness = wallNode.thickness ?? 0.1
   const halfT = thickness / 2
@@ -244,7 +245,8 @@ export function generateExtrudedWall(
 
   // Rotate so extrusion direction (Z) becomes height direction (Y)
   geometry.rotateX(-Math.PI / 2)
-  if (slabElevation > 0) {
+  // Translate by slab elevation (works for both positive and negative values)
+  if (slabElevation !== 0) {
     geometry.translate(0, slabElevation, 0)
   }
   geometry.computeVertexNormals()