Riverology 3 changes how rivers carve terrain, with the intent of working on more than the engine-native landscape that Riverology 2 requires.
The hardest constraint in Riverology 2 is not visual, it is structural: a river can only carve an engine-native Landscape actor. If your terrain is a static mesh, a heightfield you generate yourself, a voxel system, or anything else that is not a Landscape, the carving step has nothing to talk to and you are back to sculpting riverbeds by hand. Riverology 3 changes the deformation method, and the intent is that rivers stop being tied to that one terrain type.
The deformation settings live in a struct on the river actor that holds a direct pointer to a Landscape actor. Turning on Apply Landscape Spline and pressing the Editor Apply Spline button walks the spline and pushes height changes into that Landscape, optionally painting a layer along the riverbed. Deform Width controls the cross-section, where negative values cut a valley and positive values raise a levee, and Deform Falloff controls how far the change blends back into untouched terrain. Raise Heights and Lower Heights act as safety switches so you can carve without raising, or raise without cutting. Paint layer lookup goes through the Landscape's own layer info, and the writes target a named Landscape edit layer, which is what keeps the operation reversible.
Every hook in that path is typed to the engine Landscape: the actor reference, the layer info lookup, the edit layer target. Nothing degrades gracefully for other terrain — it simply does not run. It is also strictly an editor-time operation driven by a button press, which is workable for a Landscape with edit layers and has nowhere to go for terrain built at runtime.
The core Riverology 3 inherits already separates the two jobs Riverology 2 fuses together. Reading the ground is handled by a water terrain component that can be attached to any actor with primitive components, which then renders into the water info texture as terrain and can supply its own world-space triangles without depending on collision being enabled. Landscapes are still auto-included by default, but they are no longer the only thing that can be terrain. Writing to the ground is handled by a brush pipeline with blend modes, falloff modes and a stack of effects, evaluated on the GPU through jump-flood distance field, falloff, weightmap and composite passes. Splitting read from write is what makes broader terrain compatibility possible at all.
Being precise about where this stands: in the core as it exists today, the write side still installs itself as a brush inside a Landscape edit layer. That is exactly the part Riverology 3 sets out to change, and it is the part that has not shipped. Expect broader terrain support; do not plan a project around a specific terrain system until you can test it on the release build.
| Before | Oceanology Pro | |
|---|---|---|
| Terrain the river can carve | One engine-native Landscape actor, referenced directly | Intended to reach beyond the engine-native landscape; not yet shipped |
| Terrain the water can read | Only the landscape it was told about | Any actor carrying a water terrain component, with landscapes auto-included |
| When deformation runs | Editor only, on an Editor Apply Spline button press | Brush pipeline evaluated on the GPU as part of the water zone rebuild |
| Shape controls | Deform Width and Deform Falloff | Blend mode, falloff mode, edge and Z offsets, plus curve, blur, curl noise, displacement, smooth blending and terracing effects |
| Painting | One paint layer name on one edit layer | Weightmap passes inside the brush pipeline |
| Deform Width, default | -200 (negative cuts a channel, positive raises a levee) |
| Deform Falloff, default | 1000 |
| Raise Heights and Lower Heights, default | Both enabled |
| Apply Landscape Spline, default | Disabled |
| Core brush blend modes | Alpha Blend, Min (lower only), Max (raise only), Additive |
| Core brush falloff modes | Angle or Width, each with edge offset and Z offset |
| Core brush effects | Blur (radius 2), curl noise, elevation curve channel (ramp width 512), displacement, smooth blending, terracing (spacing 256) |
| Landscapes as terrain in a water zone | Auto-included by default |
This is one entry on the Galidar roadmap. For what already shipped in each release, see the Changelog.