     @worker.postMessage
       cmd: "init"
       pattern: pattern
-      chunkSize: 500
+      chunkSize: @chunkSize
       skipSteps: 1
-      size: 128
+      size: 100
       # _finishInitialize invoked on responce
     
   step: (dz) ->

    
    tube.addAttribute 'position', new THREE.BufferAttribute(blueprint.v, 3)
    tube.addAttribute 'index', new THREE.BufferAttribute(blueprint.idx, 1)
    #tube.computeBoundingSphere() #do we need it?
    return  tube

  #remove all tubes, return to the initial state.

    @scale = scale = 30
    @group = new THREE.Object3D
    @chunks = []
    @zMin = endZ / scale
    @zMax = startZ / scale
    @lastChunkZ = 0

    @group.scale.set scale, scale, scale
    @ready = false
    @taskId2dummyChunks = {}
    @nextTaskId = 0
    @chunkSize = 500
    #continue initialization after the worker is ready
    @loadFDL "$3b2o$2bobob2o$2bo5bo$7b2o$b2o$bo5bo$2b2obobo$5b2obo"
    
