Interior / Exterior Walls

Sometimes you may want different wall meshes for the outside and inside of a building (e.g. brick exterior, wood interior). There are a couple of ways to achieve this with Spline Architect, each with its pros and cons.

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Method A – Combined Mesh (Recommended for simplicity)

The easiest method is to combine both exterior and interior parts into one mesh:

1. Model or assemble a wall mesh that includes both the exterior and interior surfaces.
2. Use Actor > Convert to Static Mesh in Unreal if needed.
3. Use this mesh in Spline Architect as a normal wall.

Pros: - Simple workflow.
- Windows and doors only need one CustomPiece to cut through both sides.
- Fewer walls to manage.

Cons: - Less flexible if you want to swap out materials or styles later.

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Method B – Separate Stacked Walls (Flexible)

Another option is to use two SplineArchitectWall actors:
- One for the exterior
- One for the interior

You can keep them aligned by using an empty “control” Spline Wall with WallHeight = 0, and stack both walls on top of it.
This way, you only modify one spline, and both walls follow it.

Pros: - More flexible – you can use completely different meshes/materials for inside vs. outside.
- Automatically adjusts to spline changes.

Cons: - CustomPieces (windows/doors) must be placed on both walls, which can be cumbersome.
- Requires careful alignment of Input Key on Spline for matching CustomPieces.
- Stacking logic may behave differently depending on your setup (e.g. empty walls vs. real walls).