Halo 4's Forge mode was revealed at RTX. Certain Affinity, the Austin-based development team working on the mode, showcased new tools and features that were implemented in order to let players build things faster and more efficiently.
“You've spoken, we've listened, and we've created a magnet system!” said Certain Affinity's Mike McCarthy as he demonstrated two halves of a base matching up with each other perfectly in Forge. Other new tools included the Lock tool, which holds items in place, and the Dupe tool will create a copy of an object.
Dynamic lighting has also been added to Forge mode. All objects will cast shadows that are integrated with the environment. As a result the game was gives a warning message in order to let players know it's rendering. If there's multiple players building in Forge on Xbox Live, the light rendering warning in forge happens on everyone's screen.
Player Trait Zones are another major addition to Forge. Users can highlight any area area of the map they want and change variables such as speed, jump height, damage absorption, or vehicle use for use in custom gametypes or machinima.
Unfortunately, the Q&A session that followed the demonstration revealed that there will not be weather, time of day settings, or an undo feature for Forge.