How to use

updateChildren

method

in

com.jme3.terrain.geomipmap.TerrainGrid

  @Override
  protected void updateLOD(SafeArrayList<Vector3f> locations, LodCalculator lodCalculator) {
    TerrainGrid terrainGrid = (TerrainGrid)getSpatial();
    
    // for now, only the first camera is handled.
    // to accept more, there are two ways:
    // 1: every camera has an associated grid, then the location is not enough to identify which camera location has changed
    // 2: grids are associated with locations, and no incremental update is done, we load new grids for new locations, and unload those that are not needed anymore
    Vector3f cam = locations.isEmpty() ? Vector3f.ZERO.clone() : locations.get(0);
    Vector3f camCell = terrainGrid.getCamCell(cam); // get the grid index value of where the camera is (ie. 2,1)
    if (terrainGrid.cellsLoaded > 1) {                  // Check if cells are updated before updating gridoffset.
      terrainGrid.gridOffset[0] = Math.round(camCell.x * (terrainGrid.size / 2));
      terrainGrid.gridOffset[1] = Math.round(camCell.z * (terrainGrid.size / 2));
      terrainGrid.cellsLoaded = 0;
    }
    if (camCell.x != terrainGrid.currentCamCell.x || camCell.z != terrainGrid.currentCamCell.z || !terrainGrid.runOnce) {
      // if the camera has moved into a new cell, load new terrain into the visible 4 center quads
      terrainGrid.updateChildren(camCell);
      for (TerrainGridListener l : terrainGrid.listeners) {
        l.gridMoved(camCell);
      }
    }
    terrainGrid.runOnce = true;
    super.updateLOD(locations, lodCalculator);
  }
}

  @Override
  protected void updateLOD(List<Vector3f> locations, LodCalculator lodCalculator) {
    TerrainGrid terrainGrid = (TerrainGrid)getSpatial();
    
    // for now, only the first camera is handled.
    // to accept more, there are two ways:
    // 1: every camera has an associated grid, then the location is not enough to identify which camera location has changed
    // 2: grids are associated with locations, and no incremental update is done, we load new grids for new locations, and unload those that are not needed anymore
    Vector3f cam = locations.isEmpty() ? Vector3f.ZERO.clone() : locations.get(0);
    Vector3f camCell = terrainGrid.getCamCell(cam); // get the grid index value of where the camera is (ie. 2,1)
    if (terrainGrid.cellsLoaded > 1) {                  // Check if cells are updated before updating gridoffset.
      terrainGrid.gridOffset[0] = Math.round(camCell.x * (terrainGrid.size / 2));
      terrainGrid.gridOffset[1] = Math.round(camCell.z * (terrainGrid.size / 2));
      terrainGrid.cellsLoaded = 0;
    }
    if (camCell.x != terrainGrid.currentCamCell.x || camCell.z != terrainGrid.currentCamCell.z || !terrainGrid.runOnce) {
      // if the camera has moved into a new cell, load new terrain into the visible 4 center quads
      terrainGrid.updateChildren(camCell);
      for (TerrainGridListener l : terrainGrid.listeners) {
        l.gridMoved(camCell);
      }
    }
    terrainGrid.runOnce = true;
    super.updateLOD(locations, lodCalculator);
  }
}