Explicit frame rendering

using Makie
 using ModernGL, GLMakie
 using GLFW

 GLMakie.opengl_renderloop[] = (screen) -> nothing
 function update_loop(m, buff, screen)
     for i = 1:20
         GLFW.PollEvents()
         buff .= rand.(Point3f0) .* 20f0
         m[1] = buff
         GLMakie.render_frame(screen)
         GLFW.SwapBuffers(GLMakie.to_native(screen))
         glFinish()
     end
 end
 scene = meshscatter(rand(Point3f0, 10^4) .* 20f0)
 screen = AbstractPlotting.backend_display(GLMakie.GLBackend(), scene)
 meshplot = scene[end]
 buff = rand(Point3f0, 10^4) .* 20f0;
 update_loop(meshplot, buff, screen)
 GLMakie.opengl_renderloop[] = GLMakie.renderloop # restore previous loop
 scene