look at the 2 point constraints for this type of stuff. It gives you
control of what axis points down the joint and also to set an object as
an up vector to stabilize them. Might get rid of the need for the 2
constraints.
If you're sticking with the 2 constraints, you'd set the first
constraint to 100% and the second one to 20% and that should get you
the 80%/20% you're looking for.
The last resort would be to set keys on them but I've heard that this
can sometimes cause motion blur issues as it spins or moves a good
amount in the one frame it evals... do some tests.
On Friday, December 13, 2013 4:32:19 PM, Sergio Mucino wrote:
Okay. I wasn't aware of this. How would you do this in a setting where
you want the object constrained 80-20, for example? You don't want the
constraint to be 100, because it means the object would move all the
way with it with the constraining object, and you want it to move 80
percent only...
Can I do 'hard' constraints in Softimage?
Thanks!
On 13/12/2013 4:21 PM, David Barosin wrote:
>>>offset1 and offset2, then its constrained to both, with a 0.5
weight on each constraint.
Soft constraints are layered, meaning that the order the constraints
are applied is important. The last applied constraint trumps the
previous one. So if you want to blend a 50/50 amount you have to
leave the first constraint at 100% and the second at 50%
Think of it as the if last constraint reveals to the previous ones.
Hope that makes sense.
On Fri, Dec 13, 2013 at 3:43 PM, Sergio Mucino
<sergio.muc...@modusfx.com <mailto:sergio.muc...@modusfx.com>> wrote:
I'm running into an interesting problem with weighted
constraints. I have a feeling of what's causing it, but I wanted
to see if anyone has ran into it before.
I've got a fairly straightforward 3-arm animation setup. One
chain is the IK arm, another chain is the FK arm, and the third
chain is the deformation arm. Each joint on the deformation arm
has two orientation constraints, targeting its corresponding
joint in both the IK arm and FK arm. The weights on the
constraints are controlled by a single Custom Parameter, so I can
blend with a single control.
There are some Offset controls parented to each joint of the
Deformation arm. And there are a bunch of little nulls sitting on
the deformation arm. These nulls are position constrained to two
of these offsets each. Say, one of the nulls sits midway between
offset1 and offset2, then its constrained to both, with a 0.5
weight on each constraint.
The problem I'm seeing is that each time I move the arm(s)
(either), be it by manually moving the animation controls I have
for them, or by playing with my blending slider, these small
nulls seem to not return precisely to their original locations.
They land somewhere in the vicinity, but they have a hard time
returning to their original place. This is more notorious when I
perform fast movements (for example, by quickly dragging side by
side on the blending slider I have for my Custom Parameter). If I
drag said slider very slowly, they stand a much better chance of
coming back to their original position.
My feeling is that it's somewhat related to the fact that all the
objects constrained in all cases, were constrained with
Constraint Compensation on. Looks like all these offsets added
together are causing rounding errors during the solve. Of course,
this is just my gut feeling, but I wanted to see if anyone has
ever seen a problem such as this. I'm kinda surprised SI would
have problems with such a simple setup... there's a bit of stuff
going on (I actually over-simplified it for the purpose of this
explanation, but it's nothing crazy really), but nothing that
should break like this.
We're on SI 2012. Any pointers are welcome. Thanks!
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