The first step consists in importing motion capture data.
To do so .. just use the menu
A file selector windows is displayed .. in which you can choose the bvh file you want to import.
Once selected .. click on
You should be asked to enter a scale parameter which allow you to size the resulting structure.
Once the scale is selected .. press
The newly created structure should be facing the sky .. and lying on X-Y plan.
To see it properly ... switch to a top view (
You can press
following steps, the first frame of the bvh animation will be
used as the rest position of our armature.
In order to have it suit our model, it might be interesting to adapt this rest position at our model position .. (which might have arms set in horizontal position instead of lying along the torso)
At frame one, select a shoulder empty (
Do the same with other shoulder empty to get something similar to what's shown beside .
Now select both shoulder empties (
an armature, select the hip empty .. the one at the center of our
charater .. it should be named "_Hips" (
Open a script windows and run the
A Graphical User Interface is then displayed .. allowing you to configure
HipBoneName field must be filled with the name of the main empty of the
structure. It is automatically set to the name of the selected empty if
it is a root Empty (ie: if it has no parent).
Once all parameters are set ... Press
The previous action should lead to the creation of an armature. In blender 2.37, the armature created by BVH2ARM script is fully animated but in Blender 2.40 ..this feature is no longer available ... and only the armature's position and orientation are animated (not individual bones)
So we are going to use Blender's powerful IKSolver to perform bones'animation for us.
Select the armature and enter PoseMode (
Select a hand empty (
Insert an IKsolver Constraint on the bone (Press
This is going to make our arm follow the hand empty .
The figure above shows the ikSolver constraint as set by default after the Ctrl-I action. As we can see .. all bones are going to be
involved in movments .. In reality .. our human body doesn't use so many DoF .. For our animation to be more realistic we set up the IKSolver chain len parameter to 3 so that the IKSolver will only operate on arm's bones rather than on the whole squellet (see figure on the right).
The chain len parameter can be reached in the constraint tabspace of the Editing Panel (
Put similar IKSolver constraint on every end effector bone (hands, legs and head). For the head bone constraint, a 2 bones-long chain len should be good enough.
|The figure beside
final armature once all constraint are in shape ..
Note that we added rotation restriction on several bones of the torso in order to make our armature move in a more realistic way .
The resulting animation is below ..
We can see that Blender's IKSolver manage to produce an animation that is similar to what was captured by the mocap equipment ..
There are only small differences between the bvh animated empties .. and bones animation made by IKSolver..