old_contents: import moderngl as mgl
  from demosys.effects import effect
  
  
  class SceneEffect(effect.Effect):
      """Generated default effect"""
      def __init__(self):
          self.scene = self.get_scene("Sponza/glTF/Sponza.gltf", local=True)
  
          self.proj_mat = self.create_projection(fov=75.0, near=0.01, far=1000.0)
  
      def draw(self, time, frametime, target):
          self.ctx.enable(mgl.DEPTH_TEST)
          self.sys_camera.velocity = self.scene.diagonal_size / 5.0
  
          self.scene.draw(
              projection_matrix=self.proj_mat,
              camera_matrix=self.sys_camera.view_matrix,
              time=time,
          )
  
          # Draw bbox
          # self.scene.draw_bbox(self.proj_mat, self.sys_camera.view_matrix, all=True)
  
new_contents: import moderngl
  from demosys.effects import effect
  
  
  class SceneEffect(effect.Effect):
      """Generated default effect"""
      def __init__(self):
          self.scene = self.get_scene("Sponza/glTF/Sponza.gltf", local=True)
  
          self.proj_mat = self.create_projection(fov=75.0, near=0.01, far=1000.0)
  
      def draw(self, time, frametime, target):
          self.ctx.enable(moderngl.DEPTH_TEST)
          self.ctx.enable(moderngl.CULL_FACE)
          self.sys_camera.velocity = self.scene.diagonal_size / 5.0
  
          self.scene.draw(
              projection_matrix=self.proj_mat,
              camera_matrix=self.sys_camera.view_matrix,
              time=time,
          )
  
          # Draw bbox
          # self.scene.draw_bbox(self.proj_mat, self.sys_camera.view_matrix, all=True)
  
subject: Enable face culling in sponza example