Working with Retopo Curves

What this does:

For faster topology creation over larger areas, you can draw curves that generate polygonal strips.

Why you'd use this:

Curves excel at creating clean topology strips across smooth surfaces like foreheads, cheeks, or limbs. Rather than placing dozens of vertices manually, you can draw two parallel curves and generate an entire strip of polygons in seconds. This method is significantly faster than placing vertices individually when you need to cover broad, continuous surfaces.

Curve workflow:

1. Hold Alt and drag across the surface. This draws a green line segment with green vertices at each end.
   
   
2. Click and hold on the line, then drag back and forth to generate vertices within the segment. Doing so causes the line to conform (curve) to the underlying topology.
   
   
3. Draw another curve line parallel to the first. It automatically replicates the number of vertices in your first line and similarly curves to your topology.
   
   
4. Release the mouse button and ZBrush automatically creates polygons between your lines (shown below). Click on the surface to confirm and generate a mesh strip.
   
5. Need more than a strip? Keep drawing additional lines.
   

Dragging for rapid retopo generation

Before confirming the mesh strip, you can left-click on an edge line or an edgeloop within the strip and drag to add (or subtract) vertex subdivisions. This increases/decreases the number of edgeloops across the resulting geometry and provides an easy way to change your edgeloop count after initial mesh creation rather than recreating the mesh from scratch. For situations when you need to expand your mesh density, as when you need a retopo mesh to conform to the underlying model curvature, this approach is a huge time-saver.

Take a look at this in practice:

As covered earlier, you begin by Alt-dragging a curved line of vertices (above, left). Add a second, matching line (center), then release the mouse button to establish edgeloops between the lines (right).

Next, hold down Alt and press-drag an edge line to increase your retopo mesh's number of edgeloops (see below).

Repeat the process with the top or bottom edge to add edgeloops in the other direction.

And keep in mind that you can even add edgeloops within prior edgeloops, as shown here: