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Locomotion along specified path
May 20, 2016
3:52 am
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Hello

I've a path for object like a set of keyframes, e.g. position, rotation and velocity are known at every frame. What is a best way to get a corresponded character's motion? Should I use steering?

Thx

May 25, 2016
5:49 pm
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Steering will generate animation approximately along the path that you specify, although with no constraint on the timing (you can set the velocity of the character to some extent); you can specify the final orientation but not the orientation along the path.

If you have not only the path, but also the rotation and velocity known at each frame, you could create an animation for the base joint that adheres to those constraints, but then you would be left to animate the body according to that motion.

The simplest way to do that is to loop a walking or running motion on top of those base frames so that the legs move back and forth and swing as the root moves (I call this 'meat hook' animation; your character will be carried from place to place on a virtual meat hook).

If you want nice looking character animation that matches every frame, that is a much harder problem, and may not even be possible given the data that you have.

 

Ari

June 2, 2016
3:31 am
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Hello, Ari

Thx for your reply. Let me try to explain better. User has few chars and wants to handle them "directly/manually", using timeline, similar as he drives usual 3D objects. So typically he sets a few keyframes only (for example 30 frames of animation with one keyframe only or less yet). For him it's important to have a char arrived at concrete position in concrete time, for example "at frame 100 the Rachel should be here, with specified position, rotation and velocity". Of course with specified keyframes we can get all values for every frame - but it's unneeded, or even unwanted to apply them at every frame, only few "control/check points" should match.

Which BML command (or other technique) is most suitable to do this? As I've understood, a calculating root bone motion would make motion not natural, so what are other ways?

Thx

June 4, 2016
8:19 am
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Making a character arrive at a particular time in a particular state can be done via keyframing ('meat hook animation' - drag the character around with a virtual meat hook and have it arrive when you want it). Slightly better than that would be to animate the character with motion as it moves (arms and legs swing appropriately) although that would still give you some foot skating and low quality results. 

You could: 1) Send a locomotion command to move the character

2) write a script which slightly adjusts the position of the character in real time so as to make sure the character arrives on time and in the right state

 

Alternatively you could run the animation in real time, write that data to a file, edit it in a motion editing tool, then use the saved animation in real time.

 

In general, doing what you ask (exact timing and high quality movement) is difficult; I don't think any system can do that out of the box.

 

Ari

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