Velocity Key frames
This is an idea that I've thought of in the past but forgot about until I saw this StackExchange question here .
I haven't been able to find anything about it elsewhere, so I guess I'm posting it here. Long story short, rather than making position keyframes, make keyframes for velocity. This would greatly assist people trying to do accurate animations for vehicles for example.
Considering that velocity is just the derivative of a displacement-time graph (which is already in Blender), calculating the velocity-time graph lines shouldn't be too hard, should it?. The main issue would be trying to figure out how velocity/displacement nodes affect one another. Or perhaps it could just be mad that you had to toggle in between the two modes such that you can only be using one type at any given point in the animation.
Edit: adding in rotational velocity would also be nice.
4 Comments
What would the user interface for this look like? Would there be a separate channel, or would you set the location keyframe channel to show a velocity view?
* @Jason van Gumster * I'm not quite sure what you mean specifically by the different channels, but I'll try to explain how I think it'd work.
Adding on to the whole location/velocity toggle I was talking about in the post, perhaps the graph lines could become dotted lines to show when the property is controlled by the other one. For example, X Location showing a dotted line when the location is controlled by X velocity and vice versa.
For the Dope Sheet, you would need to create "no-go zones" for when one property is being controlled by the other, so, for example, you can't slide a position keyframe into frames where the velocity is controlling the position. This could be shown by changing the background highlighting in the"no-go zones."
You might find this useful: blenderartists.org/t/projectile-rigidbody-initial-velocities/667893
* @ammusionist * It's not quite what I'm looking for. That add-on is setting an initial velocity and rigid-body physics to an object. However, you don't have control of it after the fact. Sure you could bake it, but then editing those keyframes will now be a pain.
Say I've got a car that slams on its brakes before entering a turn. If you want all the dimensions to line up with the real world, you're going to need to manually find the change in position between frames to determine the velocity of the car at different times to determine how quickly it has slowed down (and whether or not it's realistic). Easy enough, but rather tedious and time-consuming.
From there, you've got to calculate the appropriate tire rotation speeds, and thus the change in rotation for the tires over a frame then set 4 keyframes at the start/end AND tamper with the line connecting them to match that of the car slowing down.