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)?
