Within Medieval Engineers, building is one of the largest aspects of the game. Allowing players to construct unique and amazing structures. The Game Controls along with the Building Controls specificity will help in completing any build. Understanding the basic controls and how the more complex blocks function within the game allows for thousands of block combinations for truely unique structures.
So first for the controls, the general search () gives access to most blocks or the rest can be found inside the crafting table. There is also + to move objects farther and closer to your self. These controls are truly the most commonly used when normally building structures.
|This can be activated by pressing to toggle Compound Building on/off or holding to activate it momentarily. This allows the ability to build more than one object in the same grid position. You are not allowed to compound build with all blocks but there are quite a few that will compound together. For example, two walls can be combined to make a corner.
You can see the semi-transparent wall about to be placed to the right of the built wall on the left in this picture.
|The most asked question is what is the purpose of the symbol in the top right of some blocks?
This is a Block Group. All you need to do to use block groups is scroll your mouse wheel to switch between all of the different blocks in the group when you have the group equipped. Some blocks such as the timber simply change the size. Other blocks changes the type of block. See Category:Block Groups for a list of all block groups in the game.
Dynamic vs Static Building
Static blocks are placed in the ground and do not move. Other blocks attached to static blocks are also static unless they lose their connection to the ground. Dynamic blocks are placed above the ground and can move freely. Other blocks attached to dynamic blocks may also be dynamic unless they are somehow also placed in the ground or attached to a static grid. That may seem unlikely but it can happen that you place a block on a cart and it also attaches to the floor of your castle.
When placing blocks they will usually be constrained to a local grid. This grid is defined by blocks placed nearby. When you are placing blocks they will use the last blocks that you aimed at† as the reference grid and they will align with it so long as you are looking at the ground or the other blocks. If you are aiming at the air then the block will rotate freely, not aligning with the grid.
When pasting a blueprint, it can be attached to other blocks (barring collisions), pasted statically in the ground, or pasted dynamically above the ground. When rotating a blueprint above the ground you can select if it will rotate freely or rotate according to grid alignment by pressing . When turning grid alignment on, if the block does not have a grid to align to, it will align with gravity so that the bottom of the block faces down. This can be useful when creating new buildings to ensure that they are level.
†The local grid is determined by the last grid aimed at that is not too far away. Grid distance is determined from the grid's origin point, usually the first block placed in the grid. This can lead to situations where attempting to place a block very near to a part of a grid does not behave as expected. The game sees the grid's origin point as too far away and is likely reacting to a closer grid.