Motion Builder for Retargeting
This is a brief summary on how to export motion data from ViconIQ into Motion Builder and into Maya.
*** This step should only be done when your motion data is as clean as possible.
0. Prerequisite
Install Vicon plugin for MotionBuilder ver.7.5
Prepare for your motion data (.v / .vsk file)
Model data (FBX format)
1. Exporting from ViconIQ
When in Vicon go under file and down to export. Export the file as a .v file.
Make sure while exporting that "Subject to Export" is set to "Macro".
With that complete. You are ready to import the motion data into Motion Builder.
2. Importing to Motion Builder
A. Model Preparation
In order to have your character model follow your motion data your rig must follow the same naming convention Motion Builder uses. One can view the naming convention in the navigator when character is selected and under the Character Setting tab. Another reference you could use is the Plasticman in Examples.
When the rig and character are ready, export the model as an fbx file. Give your character a unique name other than character.
B. Import .vsk file (vicon subject file)
Open Motion Builder. Insider Motion Builder go under Open Reality > Tools > ViconGP Importer.
Make sure that you selected four options on this window including "Always Create Models". Import the .vsk model related to the .v file you wish to import.
Make sure the model is facing the z axis and set the vertical position of the model to your desired position.
If you need to rotate skeleton model (i.e. model is facing to x axis instead of z), select reference node (this is top-level node of skeleton. small cross at the origin of workspace) then rotate it to facing to z axis.
Next, go into the character tab and select character. Drag the character icon onto any one of your skeleton bone (yellow stick). Select the option to characterize. It will then ask you to select biped or quadped, choose the one that is most suitable to your motion data.
Biped: Humanoid (2 legs)
Quadped: Animal (4 legged)
C. Import .v file (motion data)
Next go under Open Reality > Tools > ViconGP Importer again. Instead deselect "Always Create Models" (so there only 3 options selected) and import .v file.
At this point, the skeleton contains all the motion data that you captured in ViconIO software.
In order to bind a modeled character to Maya, you must have the same naming convention for the skeleton in your model to the Vicon Skeleton. (refer to 5. Examples below)
D. Motion Retargetting
The next step is to bring in the Maya character that was exported as an fbx file. To do so, select File > Merge. Select the correct file.
Once that is done, in the navigator box select your model under character (expand character to get to the model). On Input Type select Control Rig Input. A box will prompt you to select options to plot the animation. While you are still working inside Motion Builder select Control Rig. Then, you select either IK/FK or IK only depending on your data.
Control Rig allows you to tweak the movement inside Motion Builder like you would with a rig inside Maya.
Select input time.
Plot animaiton options
Once you are done tuning the motion data inside Motion Builder. You should select the "Input Type", and plot the animaiton to the skeleton. Motion Builder will then plot the motion data into the actual skeleton of the model, which will be apparent in Maya. If you do not plot into skeleton all changes you made in Motion Builder will not be visible upon importing into Maya.
Save your file. It is now ready for Maya.
3. Importing into Maya
Have the character model loaded up in Maya. When ready import the motion data under File > Import. Select the .fbx file you were workign on. A prompt box will pop up, select the data and make sure "Exclusive Merge" is selected on the radio button below.
Your motion data has now been successfully imported into Maya.
- Motion Builder Friendly Character (naming convention)
plasticman.mb (maya character file)
plasticman.fbx (converted to fbx format)
plasticman_character.fbx (characterized in motionbuilder)
- Sample Motion Data for plasticman
- Following video footage made by James Lee for Video Game class (CS 426, Fall '07). It shows real subject performance and retargeted character animation together.
James_Poker_Mocap.mov (640 x 480, 24MB)