Basically the guy took 24 minutes to explain a 2 minute
concept.
The main point is Modo can define
the order in which deformers are evaluated to solve
envelope weights, and envelope weights are assigned
using 'weight containers' which are logical assignments
of points to deformers. A different kind of weight map.
The example shows an arm enveloped
over 2 bones (3 joints). In Softimage you'd normally
place the bones into a hierarchy and assign the weights
to the joints. as you rotate the shoulder, the elbow
and wrist would tag along for the ride via inheritance
of the shoulder's transformation. If you rotate the
elbow, the shoulder is unaffected, but the wrist moves
because it inherit's the elbow's transformation. The
point being the deformer has to reside in the location
of the envelope deformation, and this can be
inconvenient for thinking/viewing certain problems such
as wanting to only rotate a deformer by a few degrees.
in the case of the elbow, it may already be rotated to
some arbitrary angle making adding/subtracting a few
degrees difficult to visualize.
In Modo, the weights were assigned
to the individual bones via 'weight containers' (their
version of a weight map), but the bones were not placed
into a hiearchy. they were scattered about wherever was
convenient. This allowed the artist to work with the
deformations in the local space of the deformer so if he
wanted to say, limit envelope deformations to rotations
of 10 degrees or less, the artist could easily see a 10
degree rotation and work with the deformer weights.
think of it as compensation mode for vertices of an
envelope. You apply the envelope to the defomers, but
you can then offset the vertices where you want and
maintain that relationship as metadata in the weight
container. This allows the envelope to deform as
desired, but not require the bones to be moving around
with the envelope. Personally I don't find that useful
in the general case, but maybe in a few rare niche cases
it might have some benefit. The part I take issue with
is not having bones in their usual places will make it
difficult for animators to judge how the character is
moving when adjusting keys. After all, you don't
generally envelope a rig unless it's expected to be
animated, so why disassociate the bones from the
animator's perspective?
The part of greater interest was
pre-evaluation and post-evaluation events which gives
the artist the opportunity to further modify the
resulting deformation as each deformer is evaluated.
The example given was not very good as it could be
easily replicated using linked parameters to drive a
lattice or some other easy control, but in more complex
cases could be useful for sculpting the envelope
deformation in very specific ways.
You can replicate most of it in
softimage using a different strategy than is typically
used, but some of the more advanced stuff, such as
compensation, would require a custom envelope operator
or ICE.
Matt
i want to watch it, but the speed is
killing me... anyone care to summarize the feature(s)?
