Distance From Ground

Overview

• Node Name: Distance From Ground
• Category: repeat_instant
• File: extensions/flowgraph/nodes/vehicle/groundDistance.lua

Reports the distance of the lowest point of a vehicle's bounding box from the terrain below. Uses raycasts from each of the 8 OBB corners to find the minimum clearance.

Pin Schema

Input Pins

Output Pins

Internals

Key Methods

Debug Drawing

When self.data.drawDebug is true, the node draws text labels at each OBB point showing the distance to the ground.

How It Works

1. Gets the vehicle's spawn world-oriented bounding box (OBB) via veh:getSpawnWorldOOBB().
2. For each of the 8 corner points:
   • Creates an offset point raised by zOffset units on the Z axis.
   • Calls be:getSurfaceHeightBelow(offset) to get the terrain height directly below.
   • Computes point.z - hit as the distance from that corner to the ground.
   • Tracks the minimum distance across all 8 points.
3. Outputs the lowest distance. A value of math.huge means no terrain was found below.

Usage Example

-- In a flowgraph:
-- [Distance From Ground] ← vehId ← [Vehicle ID]
--   → lowestDistance → [Compare < 0.1] → [Vehicle is grounded]

-- Programmatic equivalent:
local veh = scenetree.findObjectById(vehId)
local oobb = veh:getSpawnWorldOOBB()
local lowest = math.huge
for i = 0, 7 do
  local point = oobb:getPoint(i)
  local offset = vec3(point)
  offset.z = offset.z + 10
  local hit = be:getSurfaceHeightBelow(offset)
  if hit then
    lowest = math.min(lowest, point.z - hit)
  end
end

Key Dependencies

• veh:getSpawnWorldOOBB() - returns the vehicle's oriented bounding box in world space
• be:getSurfaceHeightBelow() - raycasts downward to find terrain surface height

See Also

• Align for Coupling (Flowgraph Node) - Related reference
• Apply Velocity to Vehicle (Flowgraph Node) - Related reference
• Boost Vehicle (Flowgraph Node) - Related reference
• FlowGraph Guide - Guide