Once you've created a
biped, you need to pose it to match the character model that the
biped will control. This is done in Figure mode, which allows you
to bend, rotate, and scale parts of the biped to conform to the
character mesh. In this lesson, you will adjust a biped to fit a character
mesh.
Character meshes are
usually built in one of two stances. The most common is with the
arms out and the legs slightly spread, like da Vinci's drawing of
the Vitruvian Man. Or, the character mesh is built in a resting position
with arms at its sides and legs together.
For this lesson, you'll
be working with a character named Dr. X.
Set up the lesson:
- Reset 3ds Max.
- On the Quick Access toolbar, click (Open File), navigate to
the \character_animation\quick_start folder,
and open dr_x_01.max.
NoteIf a dialog asks
whether you want to use the scene’s Gamma And LUT settings, accept
the scene Gamma settings, and click OK. If a dialog asks whether
to use the scene’s units, accept the scene units, and click OK.
This scene contains a character mesh named DoctorX.
Build the biped:
Now that you know how
to create a biped, you're going to use the character mesh as a template
for building the biped that will control Dr. X.
- On the Create panel, click (Systems).
- Turn on (Biped) and make sure you
can see the Height spinner in the Create Biped rollout.
- In the Front viewport, click down at
Dr. X's feet and drag up until the biped is about 1.0m in
height
This will place the center
of mass (COM) roughly at Dr. X's pelvis.
- In the Create Biped rollout, change the
Root Name to Dr. X.
NoteWhen you change the name on the Create Biped
rollout, the name is used as a prefix for all the biped’s component
parts; for example, Dr. X L Foot. If you use the usual
Name And Color rollout, only the name of the biped’s COM is changed;
all other parts remain prefixed with Biped01 (or
whatever the current sequence number is).
Position the biped:
Once the biped is added
to the character mesh, you need to adjust the biped to better match
the stance of the mesh. First, you'll adjust the position of the
biped within the Dr. X model.
- Click the Motion panel tab.
- In the Biped rollout, turn on (Figure Mode).
All changes to the biped's reference pose must
be done in Figure mode.
- In the Left and Front viewports, click (Zoom Region), and zoom
in around the pelvis of Dr. X.
The illustrations show the COM in white and
arrows pointing at the center line of the mesh.
- In the Track Selection Rollout, make
sure (Body Horizontal) button
is turned on.
- Move Dr.X, the COM, in
both the Left and Front viewports so that it lines up with the vertical center
line of the character mesh.
Adjust the legs:
Next, you'll adjust the
legs so they conform with those of the character. When adjusting
legs, you'll want to pay close attention to the key bend points
at the knees and ankles.
- Activate the Front viewport. Maximize
the viewport by pressing Alt+W,
then click (Zoom Extents).
- Select the biped's left
thigh, Dr.X L Thigh. This is colored
blue by default, and its name appears in the name field at the top
of the Motion panel when selected.
TipIf you select the mesh by mistake, deselect
by clicking outside the figures, and then try again.
- From the Track Selection rollout, click (Symmetrical).
The biped's right thigh, Dr.X R Thigh is
now added to the selection set.
- In this step, you rotate the biped's
legs to run roughly along the legs of the mesh. To make these rotations,
you'll have to switch between the Front and Left viewports. Press F and L on
the keyboard to make these switches.
Click (Select And Rotate) and
make the following rotations:
- In the Front viewport, rotate about 12.0 degrees
about the Z axis. A readout appears in yellow as you rotate the
selection.
TipSometimes the legs will rotate in parallel,
instead of in opposite directions. If this happens to you, select
and rotate each leg individually.
- In the Left viewport, rotate about –8 degrees
about the Z-axis.
- On the main toolbar, choose (Select And Non-Uniform
Scale). Scale the thighs along the X-axis until they match the skin model:
about 85 percent. Type in the value
or use the spinners while viewing the results in the viewport.
- Press the Page
Down key on the keyboard.
Page
Up and Page Down are
shortcuts for moving up and down the hierarchy. Since both thighs
were selected, now both calves are selected after you press Page Down.
- As you did with the thighs, scale the
calves until they match the mesh: about 90 percent along
the X axis.
This aligns the biped's
ankles more closely with the ankles of the character mesh.
- Press Page
Down again to select the biped feet. Scale the feet from
the Front and Left views to more closely fit in the shoes.
- On the Structure rollout, adjust the
Ankle attach value to slide the foot to better fit in the mesh:
about 0.1.
- In the Front viewport, rotate the feet
so they align with the mesh.
- Save the scene as my_drx01.max.
The procedures you've
just completed give you an idea of what it takes to align a biped
to a mesh, and that patience is the key to this process. This character
still needs work: the feet as well as the entire upper body must be
adjusted. If you want, read the following tips for biped alignment,
then use the same procedures to experiment with aligning the rest
of the biped. Otherwise, continue to the next lesson.
Tips for Biped Alignment
Here are some tips that
may help when adding a biped to a character mesh.
- The most important tip is to make sure
the COM is always aligned with the mesh.
- When scaling and rotating biped parts,
pay attention to the model in multiple viewports. A rotation, for
instance, may look good in one viewport, but another viewport may
indicate a problem.
- Examine the character mesh's complexity.
If the character is wearing mittens or shoes, you probably don't
need five fingers and toes. Adjust the biped structure accordingly.
- Remember ponytails. If the character
has a lot of hair or a long nose, like an elephant trunk, you can
use a ponytail to control that part of the mesh.
- If the character mesh has a short torso
or long neck, it may be best to reduce the number of Spine Links
or increase the number of Neck Links. You can add up to 25 links
in the neck, tail or ponytails, and up to ten links in the spine.
- If the character is carrying something
like a weapon or tool, add a Prop to control that object.