mojoDallas opened this issue on Sep 21, 2008 · 21 posts
Maxfield posted Tue, 23 September 2008 at 4:27 PM
This is a repost of some stuff I learned a while back, after much desk-biting frustration, trying to import BVH. 
They're not all my ideas - many have been trawled from long reading of the Poser forums. I'm assuming a basic knowledge of Poser and how to run python scripts.
If you haven't already, download and install the BVH Mixer python and Smoother pythons. Links to the latest versions can be found in the Renderosity Python Scripting forum.
Select Posing Camera and Skip Frames on the timeline. Bring your chosen character into the studio.
Check Figure/Use Limits. This removes a lot of the shoulder-hunching you get in BVH downloads.
Run BVH Mixer. Pick a BVH file to import. Unless your figure will be jumping around, check drop to floor. Press Go! and wait for the script to process the BVH. Close the python window and play the animation to see how it looks.
Next comes the tricky bit...!
If any limbs, etc seem to be at a strange angle, select the body part, click one of the arrows in the parameter dials and select Graph.
Make sure your graph is set to one of the joint rotations - bend, up/down, etc.
Select all keyframes. You do this by stretching the graph out so it's showing the full range of keyframes, then clicking and dragging on a clear spot in the graph window. Drag all the way to the end of the graph. Now shift-click in the blacked-out area, and drag all the way to the other side of the graph. The whole thing should now be black. With large animations, the graph can revert to unselected if you swing the cursor back onto it. Avoid this by clicking on a blank bit of the user interface once the cursor is off the graph.
Ctrl-click on the graph. Watching your figure carefully, move the selected keyframes up or down, till the figure's pose looks more natural. You may well need to do this for all rotations of all offending bodyparts, but after a little practise this takes only a few minutes.
Many free BVH downloads have glitches in them, where the figure will suddenly jerk for no reason. Find the affected bodypart(s) and look at the graph. It's often possible to cure the glitch simply by deleting the problem keyframes.
Although the figure is now in a more natural pose, it will often be trembling and jittery. You can cure this by running the Smoother script a couple of times. This removes any redundant "noise" keyframes.
TIP: before you do this, select the hip, go to the Object menu and tick Lock Actor. This stops the "pirouette" effect sometimes seen when hip rotations are smoothed.
FOR PAL COUNTRIES: Many BVH downloads seem to be for 30 FPS video, and look a little slow when applied to 25 FPS movies. To cure this, you need the brief help of a calculator.
Click somewhere on your figure's body. (You need to do this or you may end up retiming the Posing Camera, which is pointless!)
Go to Animation/Retime Animation.
With your calculator, take the length of the animation in frames and DIVIDE BY 1.2 - enter this number into the lower-right box in the Retime Animation window. Press OK. The animation will now be at its proper speed.
Enter this same number into the of window on the timeline, and press ENTER. You're asked, "Are you sure you want to delete some of your keyframes?". Click OK. The redundant keyframes at the end of the animation will now be deleted.
You can now save this BVH in the pose folder of your choice.
16) To make a good thumbnail, use ctrl-g to remove the ground. Drag the preview window till it's just about square. Use the timeline pointer to get a frame that shows off a key movement of the animation. Use the posing camera to get a good angle, where the figure almost fills the preview window.