Try

Grow Draw

Bring hand-drawn curves into Natsura with the Custom Module node, so they can be decorated and reshaped like a tree you grew. Experimental.

Grow Draw is the hand-drawn route into Natsura. You draw the branches as curves, and the Custom Module node passes them through Natsura as a skeleton, so they can be decorated and reshaped like a tree you grew. The same node is how curves imported from SpeedTree come in.

In Houdini the node is Natsura Custom Module, under Advanced on the Natsura toolbar. The curves go into its first input; it has one output.

Width

The width settings decide how thick each curve is when it comes through. With Use Existing Width on (the default), the width is read from an attribute on the curves, pscale unless you change Width Attribute. With it off, Width Attribute is greyed out.

Related

Natsura Shape (on the toolbar under Advanced) deforms the rig and its geometry after the fact, which suits reworking a hand-drawn or SpeedTree tree. To pose a grown tree by hand instead, see Interactive tools.

Status

Custom Module is experimental, this workflow is still in development, and its settings may change. Natsura Shape is also experimental. Custom Module contains a SideFX Labs node, so it needs SideFX Labs installed. The plan is for a Custom Module to be assignable to a Grow, so a drawn part takes the place of the skeleton the Grow would add.

Grow

Grow adds a chain of internodes to a tree, with control over where it starts, its length, width, angles, forks, effectors and decorations. Trees are built by chaining Grows into a Simulate.

Import Highpoly

Import Highpoly brings a high-resolution scan or sculpt into Natsura, trims it, and marks the open ends where procedural growth will continue from it.