Yeah but unfortuntaly once i make a group to execute soap bubble the grid disappears and i see that the icon soap bubble is active because it was written ( pressure ) and i wrote a pressure value but nothing appears, also i tried sand icon but also the grid disappears ,what shall i do?
You don’t have to make any group, just select the desired edges, hit Enter, and the group is created automatically by the plugin. Then select the group, as in the GIF above.