code: def compute(t):
      value = (
          np.sin(xx / 50 + t / 10) * np.cos(yy / 50 + t / 10) * 50 + 50
      )
      return dict(x=xx, y=yy, z=value)
  
imports: import numpy
  from bokeh.driving import count
  from bokeh.io import curdoc
  from bokeh.models import ColumnDataSource
  from .surface3d import Surface3d
label_desc: Use image node_id 1 for calling a global function with example usage: compute(t) and returns: dict