code: def _on_calculate_verts(self):
      self.u_interval = self.intervals[0]
      self.u_set = list(self.u_interval.frange())
      self.v_interval = self.intervals[1]
      self.v_set = list(self.v_interval.frange())
      self.bounds = [
          [S.Infinity, S.NegativeInfinity, 0],
          [S.Infinity, S.NegativeInfinity, 0],
          [S.Infinity, S.NegativeInfinity, 0],
      ]
      evaluate = self._get_evaluator()
  
      self._calculating_verts_pos = 0.0
      self._calculating_verts_len = float(
          self.u_interval.v_len * self.v_interval.v_len
      )
  
      verts = []
      b = self.bounds
      for u in self.u_set:
          column = []
          for v in self.v_set:
              try:
                  _e = evaluate(u, v)  # calculate vertex
              except ZeroDivisionError:
                  _e = None
              if _e is not None:  # update bounding box
                  for axis in range(3):
                      b[axis][0] = min([b[axis][0], _e[axis]])
                      b[axis][1] = max([b[axis][1], _e[axis]])
              column.append(_e)
              self._calculating_verts_pos += 1.0
  
          verts.append(column)
      for axis in range(3):
          b[axis][2] = b[axis][1] - b[axis][0]
          if b[axis][2] == 0.0:
              b[axis][2] = 1.0
  
      self.verts = verts
      self.push_wireframe(self.draw_verts(False, False))
      self.push_solid(self.draw_verts(False, True))
  
file_path: sympy/sympy/plotting/pygletplot/plot_surface.py
imports: import pyglet.gl
  from sympy.core import S
  from sympy.plotting.pygletplot.plot_mode_base import PlotModeBase
label_desc: Use image node_id 1 for calling the PlotSurface obj's underlying member method code with example usage: obj._on_calculate_verts() without return types