Using Quadrupeds in Poser Walk Designer
By DAD
Software needed:
3D Modeling Program
Poser (Tested in P6)
EasyPose Underground by Ajax
Introduction:
The Poser Walk Designer tab is normally
used for defining walk patterns for Biped
characters. When attempting to use this
part of the software package to create a
walk design for a quadruped, the results
are less than satisfactory as shown in
fig 1.
Fig 1
This problem is due to the fact that Poser is trying to drive the
walk by motivating the rear legs and treating the front legs as if
they are a bipeds arms. The main reason that this occurs is due to
improper subdivision of the body parts for naming the appendages and
the names assigned to the associated joints of those appendages. If
the design of the quadruped is approached from the idea that the walk
will be driven by the front legs and proper division of the
appendages and a different approach to naming the joints is taken, a
successful design can be achieved.
For this exercise a custom quadruped character is going to be used.
But these conventions can actually be applied to existing quadruped
Poser content with some success too. I will be using my cartoon
Donkey to illustrate the procedures and naming conventions used to
create a quadruped that works in the Poser Walk Designer.
Part 1: Character Design.
When designing a quadruped character for use in Poser that is planned
to be used in the Walk Designer, it is best to design the front and
rear legs with similar joint angles and separation points. You also
need to design both the front and rear legs with the idea that they
will each only have three joints. The joints for each of the
legs will be variations on the Thigh, Shin, and Foot as follows:
Right Front leg: rThigh, rShin, rFoot
Left Front leg: lThigh, lShin, lFoot
Right Rear leg: rRThigh, rRShin, rRFoot
Left Rear leg: lRThigh, lRShin, lRFoot
These naming conventions make it easy to identify which leg is
which when working with the character.
When the basic design is
complete and imported into
Poser. The joint hierarchy
should look something like this
(fig 2):
Note that the rThigh and lThigh
are attached to chest bone of
the hierarchy and the rRThigh
and lRThigh are attached to the
hip bone of the hierarchy. This
structure will allow the front
legs to drive the animation of
the walk design.
Fig 2
Once this skeletal structure is
establish in the Poser character
and the joint parameters are
set, the character design should
look as shown in Fig 3 when set
up in the Walk Designer.
Initially the hind legs will not
move when the character is
loaded into the walk Designer
but an acceptable front leg
movement should be seen at this
time.
Fig 3
At this point we need to translate the movement of the front
legs to the rear legs in a side for side swap to create a
simulated walk design for a quadruped. This will be done by
establishing master/slave relationships between joints in
EasyPose Underground.
Step 2: Master/Slave joints. (ERC)
I use EasyPose Underground by Ajax to setup and establish the
ERC master/slave relationships that are needed between the front
legs and the rear legs to translate the Walk Designer animation
of the front legs to the rear legs.
Close attention needs to be paid while doing the ERC setups
because the right front leg joints will be used to translate
animation movements to the left rear leg and vice versa for the
left front leg/right rear leg.
The ERC will be set up
using the ERC Dial control
section of EasyPose as
illustrated in Fig 4.
A control ration setting of
.5 is used so that only
half of the animation
movement of the front leg
is translated to the rear
leg. Anymore than this and
the rear foot will
intercept the front foot in
extreme positions.
Fig 4
Each master joint of the front leg must be associated with the
slave joint of the rear opposite leg as show in these charts.
Right Front Leg
Left Rear Leg
rThigh
lRThigh
xRotate
xRotate
yRotate
yRotate
zRotate
zRotate
Right Front Leg
Left Rear Leg
rShin
lRShin
xRotate
xRotate
yRotate
yRotate
zRotate
zRotate
Right Front Leg
Left Rear Leg
rFoot
lRFoot
xRotate
xRotate
yRotate
yRotate
zRotate
zRotate
Left Front Leg
Right Rear Leg
lThigh
rRThigh
xRotate
xRotate
yRotate
yRotate
zRotate
zRotate
Left Front Leg
Right Rear Leg
lShin
rRShin
xRotate
xRotate
yRotate
yRotate
zRotate
zRotate
Left Front Leg
Right Rear Leg
lFoot
rRFoot
xRotate
xRotate
yRotate
yRotate
zRotate
zRotate
Correct establishment of the master/slave ERC relationships can
be verified by looking at the slave liberator section of the ERC
Dial Management section of EasyPose as shown in Fig 5.
Fig 5
After saving the modified CR2, you can restart Poser, load the
modified character and perform a test animation in the walk
designer. The results should be similar to those in the test
animations provided with this tutorial.
Conclusion:
There are know issues involved with this procedure. Since the
joints differ slightly from the front to the rear legs there
will be small amounts of joint popping. This can be minimized by
turning IK on after the walk design has been made. Additionally,
modifying the frames where these pops occur can also smooth out
the animation. Additionally it will appear that the rear legs
float slightly above the ground. This too can be worked on and
smoothed out by editing the offending frames manually. But, for
basic cartoon style animation, this procedure provides a quick
and easy way to get your quadrupeds walking in Poser.
It is also a good idea to have a standard version of the model
without ERC and a Walk Designer version. This is useful when you
want to do a standard pose that does not require the
master/slave connection between the front and rear legs used in
the Walk Designer.
For additional information and questions regarding this
tutorial, please feel free to contact me at:
[email protected]
Written by:
David D'Champ (DAD)