Metamaterials are one of the few ways to ensure that the game will only let you place an object in a specific position relative to another object, as evidenced by the use in the manipulator, accelerator, separator, etc. addons. The file metamaterials.config defines these metamaterials. However, I do not seem to be capable of adding new metamaterials to this list, as evidenced by the fact that the game claims that any materialid I use for them "does not fall within the valid range!". Is there a specific trick to this, or is there another way of very specifically locking the placement of an object relative to another object?