I recently posted about making an forward kinematics (FK) engine for my character tool, ProxyMan. And I realised after posting about that, that I could see another benefit this new FK functionality gives me.
You see, one of the things you may need to do with motion capture when applying it to a character rig, is that you may need to reposition the character somewhere else in the scene. How do you do this?
Now, I already have a few ways of accomplishing this. But they're all a little undesired. That is to say, that while they do work, they're not the most ideal way. The most ideal way would be to have something that is deliberately controllable. And here's where my new FK system provides a pleasant surprise.
You see, the new FK engine was designed to help edit the character motion, such as changing the rotation of a head, or changing the angle of an arm. Or the height of the hips. But I realised after some playing around, that I could actually use it to offset the starting location of the animation itself. With a couple of extra features quickly added to the options menu, I was able to implement something that helped with doing just this!
Now, I hadn't fully completed the new FK engine. It still needed some work in the positional data area. But I was able to complete these with the above in mind, and I now have a really handy FK engine. I know some might find making an FK engine a little odd, given that programs tend to have this built in by default anyway. But mine is much more flexible and controllable. For instance, it has blending options not normally available in the standard ways of doing FK.
Seems as though the new FK engine really was worthwhile making.
Here's a couple of screen shots that show a null object controlling the state of a character rig. The null object (shown as the axis) was used to offset and rotate the character hips, and thus moving the complete character rig. In this example, the axis has been rotate 90-degrees, so it may not look like there's any rotation, but there is. Those with a little know might be able to spot how you can tell. The three image sequence shows the rig with zero-percent FK blend, 50% blend, and 100% blend.
