diff --git a/Core/Scripts/Constants.cs b/Core/Scripts/Constants.cs
index 30db259..642e0a6 100644
--- a/Core/Scripts/Constants.cs
+++ b/Core/Scripts/Constants.cs
@@ -23,5 +23,23 @@ namespace IslaApocalypse.Core
// Colour only. This does NOT affect terrain shape, collision, or what
// block is actually stored in a voxel.
public const float BLEND_BAND_METERS = 2.0f;
+
+ // --- ROAD GRADE TUNING ---------------------------------------------
+ // How much a road "holds a grade" instead of following every bump in
+ // the ground underneath it. Roads exist to be DRIVEN on, so this is a
+ // driveability setting, not a cosmetic one.
+ //
+ // 0.0 = hugs the land: the roadbed follows the terrain exactly.
+ // Never steps, but inherits every lump the ground has.
+ // 1.0 = holds a grade (default): each stretch of road is a straight
+ // ramp between its two path points, cutting through small
+ // bumps and filling small dips. Smoothest to drive.
+ //
+ // Values in between mix the two. Raise toward 1.0 for a more
+ // engineered road, lower toward 0.0 for a more rustic one.
+ //
+ // NOTE: this affects road ELEVATION (terrain shape under the road),
+ // not colour. Tune it properly once vehicles exist to drive on it.
+ public const float ROAD_GRADE_SMOOTHING = 1.0f;
}
}
\ No newline at end of file
diff --git a/Server/Scripts/ServerChunkManager.cs b/Server/Scripts/ServerChunkManager.cs
index c9b8f37..5170f0e 100644
--- a/Server/Scripts/ServerChunkManager.cs
+++ b/Server/Scripts/ServerChunkManager.cs
@@ -135,17 +135,36 @@ namespace IslaApocalypse.Server
foreach (var seg in localRoadSegments)
{
- float dist = DistanceToLineSegment(currentPos, seg[0], seg[1]);
+ // 'alongT' tells us HOW FAR ALONG this segment the nearest point is
+ // (0 = at the start point, 1 = at the end point).
+ float dist = DistanceToLineSegment(currentPos, seg[0], seg[1], out float alongT);
if (dist < minDist)
{
minDist = dist;
if (dist <= shoulderRadius)
{
- // Sample the heightmap precisely at the center of the road segment
- // so the whole road stays at a uniform elevation, ignoring the sloped mountain under it.
- Vector2 midPoint = (seg[0] + seg[1]) / 2.0f;
- float roadRaw = _blueprint.HeightMap[(int)midPoint.X, (int)midPoint.Y];
- closestRoadElevation = Mathf.Clamp(roadRaw * (Constants.CHUNK_HEIGHT - 5), 2.0f, Constants.CHUNK_HEIGHT - 2.0f);
+ // F2 FIX — the road elevation is now taken at the point on the
+ // segment CLOSEST TO US, not at the segment's midpoint.
+ //
+ // The old code gave every column near a segment that segment's
+ // single midpoint height, so each stretch of road was one flat
+ // plank and consecutive planks stepped up/down like a staircase.
+ //
+ // Two honest ways to read the height at our closest point:
+ // rampElevation - a straight line between this segment's two
+ // end points. Holds a grade; cuts and fills.
+ // landElevation - the actual terrain under that point.
+ // Hugs the land; inherits its bumps.
+ // ROAD_GRADE_SMOOTHING dials between them (see D-021).
+ //
+ // Either way it varies CONTINUOUSLY as we move along the road,
+ // which is what kills the steps. And because neighbouring
+ // segments share an end point, the height matches exactly where
+ // one segment hands over to the next — no seam at the joins.
+ float rampElevation = Mathf.Lerp(HeightAtPixel(seg[0]), HeightAtPixel(seg[1]), alongT);
+ float landElevation = HeightAtPixel(seg[0].Lerp(seg[1], alongT));
+
+ closestRoadElevation = Mathf.Lerp(landElevation, rampElevation, Constants.ROAD_GRADE_SMOOTHING);
}
}
}
@@ -210,21 +229,49 @@ namespace IslaApocalypse.Server
renderer.RenderChunk(newChunk);
}
+ ///
+ /// Turns a map-pixel position into a world surface height, with bounds clamping.
+ /// Same mapping used everywhere else: raw 0-1 heightmap value scaled into the
+ /// usable vertical band of the chunk.
+ ///
+ private float HeightAtPixel(Vector2 pixel)
+ {
+ int px = Mathf.Clamp((int)pixel.X, 0, _blueprint.MapSize - 1);
+ int py = Mathf.Clamp((int)pixel.Y, 0, _blueprint.MapSize - 1);
+
+ float raw = _blueprint.HeightMap[px, py];
+ return Mathf.Clamp(raw * (Constants.CHUNK_HEIGHT - 5), 2.0f, Constants.CHUNK_HEIGHT - 2.0f);
+ }
+
///
/// Calculates the shortest distance from a point to a line segment defined by v and w.
///
private float DistanceToLineSegment(Vector2 point, Vector2 v, Vector2 w)
+ {
+ return DistanceToLineSegment(point, v, w, out _);
+ }
+
+ ///
+ /// Same as above, but also reports WHERE along the segment the nearest point falls:
+ /// is 0 at v, 1 at w. The road carving needs this so it can read
+ /// the height at the spot next to us instead of at the segment's midpoint.
+ ///
+ private float DistanceToLineSegment(Vector2 point, Vector2 v, Vector2 w, out float t)
{
float l2 = v.DistanceSquaredTo(w);
- if (l2 == 0) return point.DistanceTo(v); // v == w case
+ if (l2 == 0) // v == w case
+ {
+ t = 0f;
+ return point.DistanceTo(v);
+ }
// Consider the line extending the segment, parameterized as v + t (w - v).
- // We find projection of point p onto the line.
+ // We find projection of point p onto the line.
// It falls where t = [(p-v) . (w-v)] / |w-v|^2
- float t = Mathf.Max(0, Mathf.Min(1, (point - v).Dot(w - v) / l2));
-
+ t = Mathf.Max(0, Mathf.Min(1, (point - v).Dot(w - v) / l2));
+
// Projection falls on the segment
- Vector2 projection = v + t * (w - v);
+ Vector2 projection = v + t * (w - v);
return point.DistanceTo(projection);
}