I’m in the process of showing how a gun works. I’ve got several bullets loaded into the magazine. The bullets consist of the bullet itself, and the bullet casing. After the bullet is fired from the gun, the “bolt” pulls the casing back and throws it from the gun. With this setup, I’ve got a lot of hierarchy going on and it gets to be difficult animating certain pieces. I saw that the Parent Constraint was improved with R18. If when I want to pull the casing from the gun using the bolt, is the Parent Constraint the thing to use in this case? I was looking into it and when the casing doesn’t need a parent (when it’s released from the gun), how do you tell the bullet casing not to have a parent? Do you just animate the weight of the last parent it had from 100% to 0%? Or I guess you can reassign the magazine as the parent when it’s released from the gun.
Perhaps the simples way would be introduce a parent for that part as well, so the animation of that parent could be easily swopped out.
Other than that, I prefer to have a Parent for this object, and a constrain-parent for this Parent, so the object itself can be animated without messing up the “parent—parent constrain”. Often not needed, but if, then it works just nice and a change of this specific object is done much faster than setting up all the constrains again. Also nice to have some shake animations added to the main object, so the movement change is more believable.
Great, this is excellent Dr. Sassi. I will add a parent to the shell casing. Question… when you say it’s nice to have shake animations added to the main object, what object are you referring to in your scene sketch file?
The idea is either to have additional animation to the Sphere or have a rig like “Null/Null.1/Sphere”, whereby the Null will be Constrained by the Constrain Tag, the Null.1 might get the main animation besides the Constrain (when the Tag releases the casing, or in my example the Sphere) and the Sphere would get then an Vibration Tag for example.
The concept of a gun and its mechanics sounds to me more like a lot like a well adjusted flow of inertia/energy, but each time the “driving” force changes, there will be a slight change in terms of inertia/dynamic. This might cause tiny amounts of movement. I’m not certain how conscious the audience will be about this, but you might explore this. While the Null/Null.1?sphere rig allows for separate adjustments, it is easy to add or disable such parts. My engineering background would make me look out for that, perhaps my artistically trained background would even emphasize it. But then again, I have yet to learn about weapons more, before I would be certain about such details. This is me, brainstorming.
You make some very good points here Dr. Sassi. And I really appreciate the feedback on this. I will definitely experiment with using the Vibration tag. I’m sure it would breathe just a little more life into the animation.
Hey Dr. Sassi, so I’ve got my Parent Constraint set up. However, when I move my playhead to the start of my timeline, the casing doesn’t properly return to where it should be. I read online about setting the priority. I have tried changing it to Animation…adjusted the number, etc. Just seems very buggy. Any idea about this? Here’s a video of what I’m talking about:
_31 shows a parent constrained from the start
_41 where the start has no movement. The Start Null really keeps the start, the Still null is just to keep the current position. The two nulls could be one, but I like it that way.
_51 this could be an additional constrained, priority “-10” compared to the main constrain, and it works only for frame zero, or when ever you activate the PSR checkboxes.
Thanks Dr. Sassi. I wish it were as easy as swapping out bullets and bullet casing. However, I’ve got the bullets moving up through the magazine, the top bullet is pushed into the chamber, is fired, then the casing is pulled back and ejected.
With your first two examples you provided (31 & 41), does it just come down to having the Still/Start nulls? I can try settings these up to see if it fixes my issue of the casing appearing at strange locations when rewinding my timeline playhead.
I’ve spent WAY too many hours on this whole thing, almost wanting to forget about the project. I keep running into different areas of complication as there are a lot of moving parts.
The relation which is set to each Null, are like any other part in the chain, except they don’t move, they just keep things stable for the time being. In the file _51, press play and pull the cube away, wait for frame zero, and try again.
Animations can be complex, of course. A short analysis of what is finally presented vs how reality would be is the fist step, in sorting animation projects. Then comes the part to clear from which others objects relate to which, but do not influence others after it, to create a hierarchy as a concept. In other words, action and reaction is not necessarily the the same in animation (vs reality). To just transfer how it would be in reality might complicate the set up. Hence why I gave you the file in post #8. In animation we can play like a magician: swap stuff out.
Yes, many hours, but as I typically think about such things, a problem comes back until it is solved. What ever you gain from this project, will speed up the next one. The typical, “I have a deadline and I just need a solution NOW” is not helping on the long run, the opposite is the case, looking back to a quarter century of animating stuff. Where is the fun in just getting it done? Remember the feeling of accomplishment, that doesn’t come if it was just throwing 3rd party stuff in the mix. Enjoy the project, embrace all problems, as they let you grow like nothing else will.
Yes this is very true! The good thing about this particular project is that it’s just for fun I don’t have a specific deadline I’m trying to meet. However, I started from scratch back in 2015 haha! Pretty sad, I know. Just been adding to it little by little as I get time. Thanks again sir!
Yes I know, sometimes I get the impression that we live in an “Instant gratification” time, and even a push of a button is too much, hehe. But on the end, what good memories can a single push of a button create?
When I work on my movies, I have always the feeling to be the slowest person on earth with it. BUT: who cares when it is done, right?
Enjoy the ride and focus on the parts you really enjoyed doing, when you hit a low point.
Hey Dr. Sassi. I’ve been tearing my hair out of this trying to get it to work :(
I’ve stripped down my rig/model to just it’s very basic functions. I really need this to work flawlessly so that when I move around on the timeline and switch between Takes, that the bullet casing ends up where it’s supposed to. Otherwise it will be in locations that it’s not and will mess up my renders.
So if you open my file and let it play, press the Go to Start animation button around frame 100. The bullet casing is offset from where it’s supposed to be. Is there any possible way around this? I’m totally confused as to why this wouldn’t be working and have spent countless hours trying to figure it out. Any help would be extremely appreciated.