public HashMap<String, UpdatedTerrainPatch> call() throws Exception {
// long start = System.currentTimeMillis();
// if (isLodCalcRunning()) {
// return null;
// }
setLodCalcRunning(true);
TerrainQuad terrainQuad = (TerrainQuad) getSpatial();
// go through each patch and calculate its LOD based on camera distance
HashMap<String, UpdatedTerrainPatch> updated = new HashMap<String, UpdatedTerrainPatch>();
boolean lodChanged =
terrainQuad.calculateLod(
camLocations, updated, lodCalculator); // 'updated' gets populated here
if (!lodChanged) {
// not worth updating anything else since no one's LOD changed
setLodCalcRunning(false);
return null;
}
// then calculate its neighbour LOD values for seaming in the shader
terrainQuad.findNeighboursLod(updated);
terrainQuad.fixEdges(updated); // 'updated' can get added to here
terrainQuad.reIndexPages(updated, lodCalculator.usesVariableLod());
// setUpdateQuadLODs(updated); // set back to main ogl thread
setLodCalcRunning(false);
return updated;
}
protected void prepareTerrain() {
TerrainQuad terrain = (TerrainQuad) getSpatial();
terrain
.cacheTerrainTransforms(); // cache the terrain's world transforms so they can be accessed
// on the separate thread safely
}
