Check out the latest version of a free procedural texture generator.
The new version brings support for signed distance functions, 2D and 3D SDF inputs and outputs added to existing nodes.
You can now generate lightweight, highly scalable representations of 2D and 3D forms (spheres, boxes, capsules, and tori).
The 3D signed distance functions can be applied when scattering complex 3D geometry across a texture surface. You can also perform transforms, extrusions, revolutions, and Boolean operations on the geometry, then generate a height map and normal map.
There's also a set of workflow nodes for you to mix materials via height maps so it's now easier to create complex composite materials.
You can learn more here.