By clicking on Design level on the choose level screen, you can edit existing levels or create you own. In addition to the normal editing operations you can use when playing a level, you have some extra ones available when designing a level.
When designing a level, you can create three types of curved surfaces. They remain anchored in place and can't move during the simulation, like anchored objects.
Like links, curves are defined by their two end points and you create them in the same way, by clicking and dragging between these points. Curves also have additional control points that define other parameters of the curve. Shift + click + drag to move a curve control point.
You can change the material and radius of curves in the same way as links, by selecting the curves you want to change and then editing the material or radius values.
Curves have no thickness and only their inside (concave) surfaces interact with objects, so you need to build additional objects to encase their outside (convex) surfaces otherwise things won't behave as you would expect.
A cylinder curve is a section of a cylinder whose centre passes through the curve end points. Cylinder curves have two additional control points at each end, defining the section start and end angles.
A torus curve is a section of a torus whose centre arc passes through the curve end points. Like cylinder curves, torus curves have two additional control points at each end, defining the section start and end angles. Torus curves also have three more control points to adjust the angle of the torus section and another three to rotate it.
Flat curves are a transition from the circular section of cylinder or torus curves, to a flat plane. They are useful to join curves to other objects, so you can make a continuous surface. A flat curve has two control points at its circular end, defining the section start and end angles, but only one at its flat end, defining the angle of the flat plane.
Click + drag between two control points on the same curve to create a string of links bordering the edge of the curve. This is useful to encase a curve's outside surface.
The curve edge links are created with the curve's material and the current link radius. The divisions parameter sets granularity of the subdivision. A finer subdivision means the links fit the curve better, but a coarser one may have better simulation performance.
Click + drag between two curves' end points to align the first one with the second one.
Targets don't interact with objects during the simulation – they're only used to mark an area of the game world. The rules can refer to targets, to make restrictions on where things can be built, or define the victory conditions based on an object's position.
Player-creation multiplayer levels require start positions to be defined – one base and one for each player that can participate in the level. Each player builds their creation at the base position. When joining the level, their creation will be placed at their designated start position.
You don't have to create a start position for all 16 players, but players will only be able to join a level if they have a start position defined. If there is more than one start position defined for a single player then only the first one is used – any others are ignored.
The cameras created when designing a level are available when playing that level. The initial camera used is the first one created.
For levels with cameras defined, if there are any tracked objects in the level then the camera will follow these objects when playing the level. If there are no tracked objects in the level then the camera will follow the player-created tracked objects.
Objects can be made anchored, locking them in place during the simulation. You can also anchor individual nodes, rather than whole links. When designing a level, any objects you create start off as anchored and not tracked (the opposite of when playing a level, when they start off as tracked, and can't be anchored).