Metaballs Pattern

Metaballs provide a method for creating an organic-looking surface. The metaballs are blobs ("fields") of "density" floating in space. Houdini skins a surface around areas where the density is greater than some threshold.

When two metaballs overlap, Houdini adds their field effects together. Because the density of the force field can be increased by the proximity of other metaball force fields, metaballs have the unique property that they change their shape to adapt and fuse with surrounding metaballs. This makes them very effective for modeling organic surfaces.

You can specify negative Weights to create "pusher" metaballs. This lets you create holes in the surface by effectively subtracting density.

The field is controlled by a kernel function and a weight. The kernel function controls the gradient of the density value of a metaball field from 1 (at the center) to 0 (at its outside edge). The weight scales the density to shift the location of the surface closer or further away from the center. You can currently specify the shape of the field as an ellipsoid or a super-quadric.