Seamcraft is a render kit for Unreal Engine 5.6, 5.7 and 5.8, written in C++. Rocks, posts and walls blend into the ground they stand on, hard edges get a rounded bevel, and snow, wetness, moss or dust settle on everything that faces up. No material is changed: add a component to an actor, drop a volume in the level.
It writes into the GBuffer right after the base pass, before any light is computed, so shadows, Lumen and reflections fall on the blended edge and on the snow the same way they fall on the real surface. No Runtime Virtual Texture, no material node, no engine patch, and no GBuffer channel taken over.
About 0.3 ms at 1080p on an RTX 2070 Super for mesh blending with bevel, and 0.2 ms more for the cover.
Mesh blending.
The terrain and floors take the component as Receivers; rocks, posts and walls as Blend. No IDs to assign by hand: they are picked for you, and follow actors that move.
The ground's texture is mirrored across the seam, so the edge keeps its detail instead of a blur. A height blend lets the texture's own stones climb first.
Two blending actors that touch meet halfway. A mesh without the component stops the blend, so a window in a wall is never smeared.
Three widths per actor (10, 20 or 40 cm by default).
Bevel. Hard edges of an actor get rounded on screen, only inside that actor: it never bleeds into the floor or the next prop.
Cover.
One volume covers the level, or a box, with Snow, Wet, Moss or Dust, or your own mix of color, roughness, slope, noise, second color, cavities and bumps.
Nothing under a roof: a depth capture from above keeps the cover off whatever has something over it.
Puddles on flat ground with Wet. Lakes freeze over under snow and stay water under the others.
Characters and glass stay clean.
Fade Cover builds snow up or dries a street over time, with an event when it is done. Every value can also be set from Blueprint or animated in Sequencer.
Footprints and tire tracks: a Trail component on each foot or wheel, or one Blueprint call per footstep. Deep prints in snow, dark ones on wet ground, swept dust. They fill back in over time.
Compared to Runtime Virtual Texture blending. RVT needs work on every blending material and on the landscape, and it only blends into the terrain. Seamcraft needs no material change and also blends prop into prop. RVT is cheaper once its pages are loaded: in the same scene it added about 0.03 ms with the camera still, against 0.28 ms for Seamcraft.
Works with Nanite, Lumen, Substrate (Blendable GBuffer), landscapes, split screen (each player gets their own cover), stereo (tested emulated), and perspective and orthographic cameras. DirectX 12, DirectX 11 and Vulkan.
Settings. It follows the Post Processing scalability, so the game's graphics menu drives it (Low is about half the cost of Epic). A Project Settings page holds the look, and a setup check fixes the project settings it needs with one click. A compact stencil mode leaves values 1 to 127 free for outlines and other systems.
Included: an example map with one station per effect, a manual, console variables and debug views.
Good to know. Seamcraft needs the Custom Depth-Stencil Pass set to Enabled with Stencil (it turns it on and says so), and uses the custom stencil of the actors that have its component. The GBuffer blend, the bevel and the cover need the deferred renderer; forward shading gets the lit color blend only. No mobile, path tracing or MSAA. It is screen space, so what the camera does not see (behind a mesh) does not take part in the blend. Static lighting has not been tested. Windows; Linux builds but has not been run.
Free demo (Windows): https://github.com/filipetessaro/seamcraft-demo
Documentation: https://apps.tessaroapps.com/seamcraft/docs/
Support: contato@tessaroapps.com
PS: Have an idea for Seamcraft? Send it to contato@tessaroapps.com. Feature requests shape the next updates.