Smooth neighbour terrains

[Besjan]

• [x] Test increasing curve sample rate to fix angle smoothing
• [x] Skip 1m beyond boundary
• [x] Fix points of different heights not smoothing correctly
• [x] Get projected point height on terrain
• [x] Project point on 2D curve
• [x] Use points
  • From boundaryPoints get those inside tile
  • Get closest boundaryPoint to current point, using 2D distance
  • Calculate smooth amount
• [x] Fix heights at tile limit
• [x] Use single curves for each terrain
• [x] Increase curve resolution and project correctly to terrain
• [x] Define projection from / to
• [x] Foreach point in terrain
  • If point is outside terrain
    • Lower point height relative to distance from curve