protected void removeQuad(TerrainQuad q) {
        if (q != null && ( (q.getQuadrant() > 0 && q.getQuadrant()<5) || q.getParent() != null) ) {
            for (TerrainGridListener l : listeners) {
                l.tileDetached(getTileCell(q.getWorldTranslation()), q);
            }
            q.setQuadrant((short)0);
            this.detachChild(q);
            cellsLoaded++; // For gridOffset calculation, maybe the run() method is a better location for this.
        }
    }
Convert the cell coordinate (integer coordinates) into world coordinates.
jme3-terrain/src/main/java/com/jme3/terrain/geomipmap/TerrainGrid.java