Retaining Walls on Terrain
Draw a wall line and instantly see the terrain step up on the retained side, with a smooth blend back to natural grade.
Retaining Walls on TerrainWhen you place a retaining wall parametric structure on a terrain surface, Scapiera can automatically deform the terrain to match the wall's position and height — creating the cut at the high side (where earth is retained) and the fill transition at the low side.
The deformation is driven by the wall's base line position and the configured wall height. A blend curve setting controls how the terrain transitions from the wall base to the surrounding undisturbed terrain on both sides.
Place a retaining wall on terrain
Draw a retaining wall using the Wall Wizard (Hardscape → Wall Designer) or place an existing wall entity on a canvas that contains a terrain entity.
When a wall is positioned on terrain: 1. Select the wall entity 2. In the wall inspector, look for the Terrain Deformation section 3. Enable Deform terrain at base toggle
The terrain surface immediately deforms along the wall's base line:
- On the retained (high) side — the terrain is cut to match the height of the wall at each point along its length
- On the free (low) side — the terrain remains at its existing level at the wall base, then transitions outward
Configure the blend curve
The Blend Curve setting in the Terrain Deformation section controls how the terrain transitions from the wall base outward to the undisturbed terrain level:
- Linear — the terrain slopes evenly from the wall base to the natural level over the blend distance
- Concave — the terrain curves upward quickly near the wall, then flattens — creates a tight cut with a flat area further away
- Convex — the terrain curves gently near the wall, then drops more steeply — creates a gradual bank near the wall with a sharper transition further out
- Step — creates a flat area at the top of the deformed zone then a vertical drop (for stepped terrace designs)
Also configure:
- Blend Distance — how far from the wall the terrain transitions back to the undisturbed level (in meters)
- Deform High Side — whether to cut the terrain on the retained (high) side (default: on)
- Deform Low Side — whether to create a fill slope on the free (low) side (default: off — usually the low-side ground level is undisturbed)
Review the deformed terrain
After configuring deformation, switch to the 3D view to review the result:
- The terrain surface meets the wall base on both sides
- The high side cut shows the terrain dropping to the retained level
- The transition back to natural terrain follows the configured blend curve
Enable the Slope Heatmap or Contour Lines overlay in the terrain View tab to check the slope character of the blended zone — ensuring it is within practical gradients for the proposed ground treatment (turf, planting, gravel).
If the result is not as intended, adjust the Blend Distance and Blend Curve settings in the wall inspector and the terrain updates in real time.
Set the wall height
Select the newly placed wall entity to open the Retaining Wall Deformation section in the inspector. Confirm that Enable retaining wall deformation is switched on. Enter the desired value in the Wall height field — this is the elevation difference in meters (or feet in imperial mode) between the upper and lower terrace. The default is 1.0 m.
Choose which side is high
Use the Upper side selector to specify which side of the wall line becomes the retained (elevated) terrace. Left and Right are defined as you walk forward along the line from start to end. If the terrain steps up on the wrong side, switch from Left to Right (or vice versa) and the terrain flips immediately.
Adjust the blend zone
Set the Blend distance to control how far from the wall the terrain takes to transition back to natural grade. A short distance (0.5–1 m) creates a sharp cut close to the wall; a longer distance (3–5 m) produces a gentler slope. Use the Blend curve selector to choose the transition shape: Smooth (default, S-curve), Linear (constant slope), Ease in (slow start, fast finish), or Ease out (fast start, slow finish).
Verify the result in 3D and with analysis overlays
Switch to the 3D view to inspect the stepped terrain from a perspective angle — confirm the upper terrace is level, the wall face is clean, and the blend zone looks natural. Return to the Terrain workspace and enable the Slope or Contours overlay from the View flyout to check that the blended zone sits at a buildable gradient and that cut/fill volumes are as expected.
Use a short blend distance (0.5–1 m) with the Smooth curve to create a tight terrace with a flat upper platform. For a naturalistic slope that transitions gradually into the retained level, try a blend distance of 3–5 m with Ease out.
Retaining walls work on line, polyline, and bezier-path entities. A curved bezier wall follows the exact path of the curve — the terrain step curves with it. Draw the entity first using the standard 2D drawing tools, then enable the retaining wall deformation in the inspector.
The wall height is the vertical step in the terrain model, not a structural wall specification. Retaining walls in real projects require engineering for structure, drainage, geotechnical loading, and local building codes — always consult a qualified structural or geotechnical engineer before construction.
Frequently Asked Questions
Which entity types can act as retaining walls?
Line, polyline, and bezier-path entities all support the retaining wall deformation. The tool is not available on closed shapes like rectangles or circles. For a curved retaining wall, draw a bezier-path along the wall's centre-line — the terrain step will follow the curve exactly.
How do I know which direction is 'left' and 'right'?
Left and right are defined relative to the direction of the path from its start point to its end point — imagine walking along the line from the first vertex you placed to the last. The left side is on your left hand and the right side is on your right. If the terrain steps the wrong way, simply toggle the Upper side selector between Left and Right.
Does the retaining wall affect cut/fill calculations and slope analysis?
Yes. The wall reshapes the actual terrain surface used for all analysis. Cut/fill volumes, slope callouts, and contour lines all reflect the stepped ground after the wall is applied. The wall is part of the graded design, not a decorative overlay.
Can I temporarily turn off the deformation without deleting the wall entity?
Yes. Select the wall and switch off Enable retaining wall deformation in the inspector. The terrain returns to its undeformed state, but all your settings (height, side, blend distance, blend curve) are preserved. Switch the toggle back on to re-apply the step at any time.
Can I place multiple retaining walls that interact with each other?
Yes — you can place several retaining walls on the same terrain to model terraced levels. Each wall deformation is applied independently and they combine to form the final terrain surface. For complex terraced sites, check the overall result in 3D after placing each wall to confirm the levels read correctly where walls are close together.