Grouping Metaballs

Metaballs can be grouped together to prevent other Metaballs from affecting them.

In the example below, two positive Metaballs (green and red) are grouped and placed next to a positive and negative Metaball.

The ungrouped Positive Metaball is affected by the Negative Metaball, but the grouped Metaballs are not.

If we ungroup the red and green Metaballs, they then can be affected by the other Metaballs, both positive and negative.