Choose to build any object that may be rotated (doors, filters, bridges, etc.), rotate once, then use the mouse to change its material.
Although the preview shows the object is in its rotated position, when deploying the building, it is deployed in the default rotation.
- Select to build any object that may be rotated (door, filter, bridge, etc.) - Rotate once with 'O' key - Use mouse to change its material (e.g. from Gold Amalgam to Copper Ore) - Deploy the building