Good catch! I see exactly what is happening in the screenshot and video. The
shapes are forming correctly, but they look hollow and paper-thin because you
can see right through the walls.

This is a classic 3D graphics bug: **Triangle Winding Order.**

When generating a 3D mesh, the order in which you define the three corners of
a triangle (Clockwise vs. Counter-Clockwise) tells the engine which side is
the "outside" and which is the "inside." The developer session accidentally
defined almost all the triangles for the wedge in a Clockwise order. Because
Babylon.js expects Counter-Clockwise for the outer shell, it applied backface
culling to the *outside* of the blocks, rendering them inside-out!

Let's fix the mathematical winding order to guarantee these blocks are
completely watertight and solid from the outside.

### The Fix

Open `/mnt/mesh_shared/3d/3D-TS/mesh_worker.ts` and locate the `// ---- Point
Type 1 : Ramp / Wedge (y <= z) ----` section inside the `generateChunkMesh`
function.

Replace that entire `else if (pt === 1)` block with this mathematically
corrected version:

```typescript
                // ---- Point Type 1 : Ramp / Wedge (y <= z) ----
                else if (pt === 1) {
                    // Bottom face (y-)  CCW: A -> C -> D, A -> D -> B
                    if (!neighborSolidNotRamp(x, y, z, 0, -1, 0)) {
                        addTri(A, C, D, x, y, z);
                        addTri(A, D, B, x, y, z);
                    }

                    // Back face (z+)  CCW: C -> D -> F, C -> F -> E
                    if (!neighborSolidNotRamp(x, y, z, 0, 0, 1)) {
                        addTri(C, D, F, x, y, z);
                        addTri(C, F, E, x, y, z);
                    }

                    // Left face (x-)  CCW: A -> E -> C
                    if (!neighborSolidNotRamp(x, y, z, -1, 0, 0)) {
                        addTri(A, E, C, x, y, z);
                    }

                    // Right face (x+)  CCW: B -> D -> F
                    if (!neighborSolidNotRamp(x, y, z, 1, 0, 0)) {
                        addTri(B, D, F, x, y, z);
                    }

                    // Top sloped face  CCW: A -> B -> F, A -> F -> E
                    addTri(A, B, F, x, y, z);
                    addTri(A, F, E, x, y, z);
                }

```

### Test the Correction

Save the file and let Vite reload the page.

Because you are still injecting `voxelData = 3` on left-click in
`renderer.ts`, clicking will continue to place ramps. However, this time, the
normals will face outward. The wedges should look completely solid and block
light properly, giving you that fully closed, watertight geometry you asked
for.

Let me know if this locks in the topological building blocks perfectly! If it
does, we can start discussing how to trigger standard cubes (Point Type 0) vs
ramps (Point Type 1) in the UI.