Drainage, water and material transport¶

These nodes are in Landscape Processes. Connect the terrain to height. Their scalar outputs can drive masks, color maps or heightfield exports. Distances use a fraction of terrain width; depths use graph height units before the terrain's display scaling.

Drainage Conditioning¶

Method selects the drainage treatment. Cut Outlets lowers connected outlet paths through closed depressions. Fill Depressions raises depressions until they can drain. Minimum Gradient controls the smallest rise along those paths and defaults to 0.0005. Terrain heights are stored with finite precision, so very high elevations may require a slightly larger representable rise.

Use this node before Hydraulic Erosion, Channel Carving or Runoff Mask when closed sinks interrupt the intended flow. Filling changes the interior of a basin; cutting preserves its low floor and removes the obstructing outlet. Inspect the fill and cut outputs to locate added and removed thickness.

Outlet Width expands the banks of significant excavated paths and uses a fraction of terrain width. It applies to Cut Outlets; zero keeps narrow cuts.

Strength blends the conditioned result with the source. An optional mask protects areas from editing. Strength below 1 or partial masking can retain sinks; complete drainage is only established for the unrestricted result at full Strength. Strength 0 returns the source and empty change maps. Conditioning can change an intended lake basin, so keep a separate source branch for lakes when necessary.

Complex winding drainage paths can take longer to calculate. A calculation that cannot finish shows an error on the node.

Rock Collapse¶

Rock Collapse detaches exposed rock along fracture zones, then transports the detached material downhill into scree. Connect Fracture Network > fractures, Cracks or a custom scalar field to fractures. Bright values describe weak joints. Without this input, Seed generates a spatial joint pattern.

Fracture Threshold selects weak joints. Damage Steps propagates failure along connected weak regions. Block Scale sets the neighborhood used to identify exposed blocks. Block Release extends detachment from connected joints into adjacent blocks. Its default is 0; increase it for more extensive block failures. Strong release can cover small source detail with debris, so inspect wear and deposit before increasing Break Depth. Break Depth, multiplied by Strength, limits detached thickness. Rock Resistance and the optional hardness input reduce detachment; hardness 1 protects solid rock. The optional mask limits detachment and debris transport.

Settling Steps controls transport duration and Debris Spread controls travel reach. wear measures detached thickness, deposit measures the remaining loose material, and damage shows local failure susceptibility. The resulting height equals source height minus wear plus deposit. Material remains inside the heightfield and total volume is conserved. Strength 0, Break Depth 0, Rock Resistance 1 or Fracture Threshold 1 leaves the source unchanged and clears the maps.

This is a heightfield rock-failure and debris model. It does not create overhangs, detached mesh objects or rigid-body boulders. Use Rock Weathering to recede the surface without depositing material, or Rock Collapse to move the debris as well.

Surface Wash¶

Surface Wash cuts shallow, connected grooves along accumulated runoff. Apply it after shaping the larger landforms. Removed material leaves the terrain; sediment transport is not simulated.

Wash Depth limits recession and Strength scales it. Groove Width controls the physical width; Flow Threshold selects drainage paths. Local Scours varies depth along those paths, and Seed changes that pattern. Automatic wash suppresses unstructured nearly flat areas. An optional flow input replaces automatic runoff and lets you select wash regions on flat surfaces. An optional mask protects terrain. wear is removed thickness and channels shows the affected footprint. Strength 0 or Wash Depth 0 returns the source and empty maps.

Closed sinks can interrupt automatic runoff. Use Drainage Conditioning first when continuous grooves through those basins are wanted. Compared with Hydraulic Erosion, Surface Wash provides direct shallow-depth control and no sediment-transfer simulation.

Sediment Blanket¶

Sediment Blanket supplies material across the terrain and settles it into slope-stable deposits. It supports general soil, sand or snow-shaped terrain layers, independently of a specific fan or cliff supply location.

Layer Thickness sets supplied depth and defaults to 0.02. The optional thickness input multiplies it; values below 0 supply nothing. Grain Variation adds coherent thickness variation, and Grain Frequency sets its frequency. Seed changes the pattern. Grain Variation 0 gives uniform supplied thickness.

Stable Slope is the allowed rise divided by horizontal distance. Settling Steps controls progress towards this slope; more steps permit additional redistribution. Spread changes transport reach. Grain Angularity varies local material stability during transport independently of the supplied thickness. Spread 0 adds the supplied layer without transport. The optional mask limits both supply and transport; fully protected boundaries cannot be crossed. deposit measures added thickness, including material still moving when the selected steps finish. Transport conserves supplied volume. Layer Thickness 0 returns the source and an empty deposit map.

River Network¶

River Network creates waterways from selected headwaters. Connect a scalar sources mask to control their positions and relative water supply. Without that input, Headwaters and Seed select source patches preferentially on elevated, sloping terrain. Empty or fully protected sources leave the terrain unchanged. Source Water scales supply. A connected mask limits supply and incision. Fully protected terrain retains its source height, which can interrupt a waterway across an existing barrier.

A connected sources field supplies water throughout its positive regions. Use small isolated patches for individual headwaters. Broad bright regions can produce dense local waterways, particularly with a low River Threshold.

Channels can cut outlets through closed depressions. Depressions outside the active channels remain unchanged. River Threshold selects sufficiently strong accumulated flow. River Width sets the maximum channel width; lower-flow tributaries are narrower, Bed Incision cuts the bed, and Water Depth adds water above it. Water Depth is limited to Bed Incision so the surface stays within the carved cross-section. Bed Incision 0 leaves the source unchanged and clears water outputs; the flow output remains available. Source Water 0 also clears flow.

This constructs river terrain and water heightfields; it does not run time-dependent fluid dynamics. Use height for terrain export, and export surface, depth or water on separate branches when downstream tools require water data.

Automatic paths can contain straight or angular sections across flat depressions. Use Guided River when a specific channel course must be preserved.

Water Basin¶

Water Basin fills the basin connected to Source X and Source Y. A connected sources mask replaces the single source and can select several basins at the same level. Water Level is capped at the lowest selected basin outlet, preventing water from escaping over its rim. Sources above the effective water level produce no water. An empty sources mask produces no water.

Water occupies only connected terrain below the effective level. Other low areas across separating ridges remain dry. The optional mask clips water coverage. Shore Width controls the band on both sides of the wet boundary.

height retains the terrain bed. surface is the horizontal water surface in wet areas and the source terrain elsewhere. depth measures water thickness, water is its coverage mask, and shore provides the border band. For different basin levels, use separate Water Basin nodes.

To inspect water in the terrain preview, connect surface to Terrain Output > height and use water to blend a water color with the land color through Material Blend. Keep the height branch for exporting the submerged bed. These outputs are heightfields and masks; they do not automatically create a separate Blender water object.

Resolution and memory¶

Terrain and water use the selected resolution. Increasing it can reveal new channels, barriers and fractures; inspect water and debris again at the export resolution.

Complex graphs can require substantial RAM and longer calculation times. Material may still be moving when the settling calculation ends. Increase the settling steps when more time is needed to form stable deposits.

16K graphs with several branches and connected outputs can require tens of GiB of RAM. Large jobs check available memory before starting. If a graph exceeds the available memory, reduce resolution, simplify the graph or close other applications.

Leave enough GPU memory for Blender, the terrain preview and other applications as well as the terrain calculation. See Native resolution and memory.