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Tuesday, August 5, 2014

Motion Builder - characterizing, making a template, and using BVH files in story mode

Motion builder is a bit confusing at first. Here is a quick description of the steps you need to use BVH files in MB and more specifically to use them as clips in story mode.

We will cover:
1. Making sure sure the BVH file you are trying to use has a single frame of t-pose at it's beginning for either making a bone template or using a BVH file as a clip.

2. Creating a bone template from a BVH which you can use on all other BVH's with the same naming convention. Even BVH files from the same company or website may have different naming conventions. So you must create a different bone template for each possible set of BVH files.

3. Using the bone templates you create to quickly characterize any of your BVH files.

"Characterizing" is simply Motion Builder linking the BVH skeleton's bone names to it's own MB bone system called HIK 2014.

Make a first frame T-pose on the BVH file you are going to use.

Open your BVH clip in motionbuilder. Drag and drop it into the viewer from exploror and select BHV options. Select your desired frame rate and make sure the takes are selected. and press import.

1. First make sure it's facing Z positive axis

2. Select one bone in the viewer by double clicking it. Then in the Navigator on the left right click on the bone selected and choose "all branches" to select all bones in your character.

3. Goto frame 0, turn on autokeyframe,

hit E to go to rotation mode in your viewport. then in the bottom right of the 3D viewport enter 0's in the XYZ positions for all select bones (regardless of what may already be in those fields). This will cancel out all positions and the character should now be standing with hands at sides.

4. Double click in the viewer somewhere to deselect all. Then double click the shoulder bone on the right and enter 90 in the Z position for rotation of that arm.

5. Do the same on the left side only with -90

Now your character is standing in the tpose at frame 0. Turn off the little blue auto key under key controls so that you don't accidentally make any other keys you don't want.

Next step learn how to make a bone template.