Last week at the Game Developers Conference, Epic Games held several technology demonstrations of the capabilities of new versions of the Unreal Engine. In addition to the short film Rebirth, which showed photorealistic graphics created using Megascans and the mesmerizingly beautiful Troll, which focused on ray tracing technology, the new Chaos physics and destruction system was presented, which will replace NVIDIA's PhysX. A week later, the developers published the full (almost four-minute) version of the demo dedicated to her.
The events of the short film take place in the world of Robo Recall. The leader of the resistance machines k-OS, who stole secret developments from a military laboratory, is running away from a steel giant pursuing her, destroying everything in its path.
Below you can watch a 22-minute recording of one of the State of Unreal sessions, where Unreal Engine Senior Evangelist Alan Noon talked about the use of Chaos, demonstrated its use in the editor and commented on certain points of the techno demo.
According to Nun, the main advantages of Chaos are the ability to create basic destruction directly in the editor and add particle effects from the built-in Cascade editor and sound effects, as well as the convenience of working with both closed and open locations. At the same time, to create more complex destruction, you will need third-party tools (for example, 3ds Max or Maya). Among the minuses, the use of a third-party API was also named.
The new system allows you to create destruction of any scale - from a small model (for example, a person) to huge objects (buildings and entire blocks) - and view each change right in the editor. Chaos supports the Niagara effects editor, with which you can achieve even more interesting results. One of the most important features of the system is high performance: due to the economical use of resources, Chaos can be used not only on large platforms, but also on mobile devices.
Among the advantages of Chaos, a company representative emphasized the connection with the gameplay. βUsually, destruction does not have a serious impact on gameplay,β he noted. - When large debris falls to the ground, the AI ββdoes not know how to react to them. [Enemies or characters] start to get stuck in them, go through them, and so on. We want the navigation mesh to change after the collapse so that the AI ββunderstands that there is an obstacle on the way and needs to be bypassed. Another innovation is the ability to make holes in surfaces. If you are inside a building and there is a hole in the wall, the AI ββwill βfigure outβ that you can go through it.β
According to Noon, the columns at the bottom of the building in the short (0:40) can be destroyed, causing nearby structures to collapse - they are all connected by special graphs (connection graph) that are created automatically. In the scene where the city block begins to collapse (from the 3:22 mark), simulation caching is used, a technique used for large-scale destruction. This is not about full pre-rendering: if the player shoots at the debris, this will change the trajectory of their movement and can split them into even smaller pieces. The playback of such a simulation can be slowed down, accelerated, reversed, or paused.
Chaos is in the early stages of development and could still be significantly changed. Its early version will be available in Unreal Engine 4.23.
Epic Games has published other entries from GDC 2019. These include detailed stories about the ray tracing technology from the Troll tech demo (50 minutes), the practical application of this development in creating βvisually attractiveβ environments in games, its advantages and disadvantages, as well as the secrets of improving performance (28 minutes), sound rendering (45 minutes), creating realistic animation with the Control Rig tool (24 minutes), and special effects using Niagara and Blueprint (29 minutes).
Source: 3dnews.ru