It’s In the details: An introduction to modeling with subpatch
weight in Lightwave 3D.

First
we will discuss what subpatch weightmaps
are and how they work.  Weightmaps are vertex maps in Lightwave
that hold various information, from deformation, to
smoothing, to color.  Today we will
be looking at vertex weightmaps in use with modeling subpatch objects.
Subpatch objects can utilize a special type of
weightmap that affects the smoothing bias of each
point in the object.  This allows
you to create objects with much more accuracy and greater control without
adding complexity and geometry to the cage.  The object at the right is a simple
example of subpatch weight being used to add detail
to a model.

Weightmaps, when applied to subpatch objects (subpatch weight), allow us to change the bias or affinity of the surface
toward or away from the points.  In
weight shaded mode, darker red symbolizes a positive affinity, darker blue a
negative and the grey/green coloring symbolizes neutral or
normal subpatch smoothing.

When working with a subpatch
object, if you press “d” to bring up display properties you can
turn on “Show cages” this will show you an outline of the original
non subpatch geometry.  Here you can see the points and select
them easily.

Here,
cages are turned off, but you can see my point selections.  Selecting the four points on the right
and changing their weight to 100% changes the affinity or bias and bends the
geometry out to meet the points of the non-subpatch
mesh.  On the other side I selected
the other two points and set them to -100%.  As
you can see they shy away from the control points along the same direction just
its inverse.

This technique is amazing for adding edges to objects
without slicing them with Knife or Bandsaw.  It is really amazing how many complex
objects you can make with very little
geometry.

When
you have an object loaded up into Lightwave, look to
the lower right corner.  Select “W” for weightmap
editing, and then pull down to “SubPatch Weight”.

Then
go to the “Map” tab at the top.

Now
we want to select the “Weights”
tool from under “Weight and Color”
on the left side.  This tool allows
you to change the weight map value for a given point or set of points.

If
you press “n” to bring up the
numeric options for the weights tool, you will see a place where you can type
in an exact amount, or add a falloff type to your selection.  I find “none”
to be the most useful in situations where you just want to grab some points and
harden or soften them.

Now select the points you want to change and click and drag
the weights tool.  You will see
their bias change and move to or away from the points of the cage object.