Flax Engine 1.13 adds DDGI specular reflections, occlusion culling and .NET 10

Flax Engine 1.13 is out, according to GameFromScratch. The release moves the engine's base runtime to .NET 10 LTS, which brings C# 14. The report says .NET 8 reaches end of life this year, and that the team showed the new runtime running on Nintendo Switch.

Rendering gets the most changes. DDGI, the real-time global illumination system, now samples and filters better in areas far from probes, which keeps indirect shadowing intact. A new option renders indirect lighting at half resolution with bilateral upscaling. DDGI can also place specular probes so rough surfaces get dynamic reflections without Environment Probes. On the demo level this costs about 49 MB of VRAM and 0.5 to 0.9 ms of GPU time on a 2080 Ti.

Other rendering additions include PCSS soft shadows for point, spot and directional lights, and occlusion culling based on hardware queries and HZB. Culling covers models, particles, terrain, foliage and dynamic shadows, and you can plug in your own methods. Skinned meshes that are identical can now be drawn in one call, and a demo ran 5,000 animated characters at 60 fps. TAAU lets temporal anti-aliasing upscale the image, and the FSR plugin now targets AMD FSR 4.

Flax can now render multiple viewports into the main window, each with its own GUI region, for split-screen local co-op. A racing sample built on the Arizona Framework shows it with multiple HUDs. A new Online Platform sample covers player avatars, achievements and friends lists, and uses new IOnlinePlatform features for overlay UI and rich presence. On desktop, games now switch audio output automatically when the player changes devices.

Tooling changes include a search field in the properties panel, a rebuilt wireframe debug view, resizable nodes, and a GPU memory profiler that can preview and save resources. Behavior Tree decorators show condition text colored by result in play mode. Scripting gains ScriptingObjectInterfaceReference<T> for referencing objects by interface in C++ and C#, and RenderToTextureControl can apply a custom material shader to rendered UI.

Before upgrading, note that Reversed Z is on by default. The depth buffer now runs from 1 to 0, which improves precision at distance and large-world rendering, so custom shaders or depth-dependent effects are worth testing. The source is a third-party report, so check the official Flax 1.13 release details for full notes. The roadmap lists Flax 1.14 for Q1 2027 and 1.15 for Q3 2027, with 2.0 targeted for late 2027 and full backward compatibility as the aim for moving projects over.