mechanical animation

#1

Hej folks,

I´m trying to set up a rigging for a valve gear animation.
You can see a well done 2D example for that in the attached gif.

It´s not a pay-job in the moment, it`s more about learning EIAS.
I wonder if it is possible at all to set up mechanical stuff like that in EIAS
in a logical and functional way.
What i mean is…it would be nice to have the lever arms rigged in a way that when I move/animate the piston, the rest moves and turns in the right way…as it is in reality.

Ok…may be all in all that is to complex for the beginning.
I would be glad enough to find a way how to rig this single transformation of the right/left piston movement to the turning wheel in the middle (the strong gray lever arm rotation).
I tried everything from bones, effectors, all kinds of linkage and constraints, but I couldn`find the right solution. This lever arm needs two pivots.
Some of that stuff could surely be done in XP. But I ended up with weird sinus or exponential functions and a smoking brain.
There was a moment I even heard my math teacher laughing inside my head…:wink:

Does anyone know EIAS-Tuts teaching mechanical stuff like that ?

Cheers
Tom

#2

This subject was covered extensively at Postforum.com awhile back.
Jens provided some great solutions, if I remember correctly.
Check out postforum.com and do a search on “piston” and you should come up with some answers.

JM

#3

Thanks for your hint.
I searched for that postforum threads and went through it.
Unfortunately they are over two years old and so the links to the example files
(scripts, jpgs and whatever) doesn`t work anymore ;-(
But all in all …puuh…this seems to be hard stuff.

Cheers
Tom

#4

Did you have a look at the Piston and the Aim Constraint Tutorials in Electro303?
Theses tutorials are now at Paralumino. This might start you in the right direction.

http://electro303.paralumino.com/electro303/02-tech/tech_adv-p02.html

#5

I believe that was me that Jens was helping. I had to animate this engine for a project:

http://www.eitechnologygroup.com/gallery/image_full/344/

It uses IK chains on the piston rods as well as geometry constraints to follow the camshaft and everything is tied together using XP so when I turn the crankshaft, the entire engine works as expected. It’s certainly not a simple setup, but with some patience, what you are looking for is certainly possible. In this case all I have to do is set rotation keyframes as fast as I want to see the engine moving.

Jens is certainly the engine master, so any specifics are probably better suited to him since it’s been more than 2 years since I even opened that project.

Hope this helps!

Ryan

#6

Aaah…paralumino…thanks
Thats why I couldnt find that piston tut…:wink:
But anyway, I could get some steps further on my own meanwhile.
It`s still not done completely, but I´m getting closer.

Impressive work gdogfunk…

Cheers
Tom

#7

Sorry if I’m interrupting anything, but I thought I’d show you what I managed to do with it…
I love trying to figure out stuff like this, so I spent yesterday evening modelling it and this morning trying to get it to move like the gif…

I put a couple bars in the wrong place so they intersect… but easy fixes.
Two parts slip and I’m not managing to find an easy fix, so those are 2 problems…
If you want to see the project, give me an e-mail address to send it to.

But yeah, here’s a video of my attempt…
http://www.x1.ltd.uk/brooks_website/SharedStuff/Engine.mov

#8

Wow, very nice. Any chance you could post the project file?

_mike

Oops, didn’t see comment about sending e-mail. I have done so. Please ignore this msg.

#9

Nicely done! When everything is fixed I think it would make a very useful tutorial…

#10

Hey BJ. I’d love to see that animation taken farther.
Maybe a lone, antique locomotive puffing up the track.
Even a single camera angle with nothing but a rotoscoped sepia background.
The way the parts move is pretty cool.

JM

#11

I modeled this in EIM a few years ago. My next step was going to be the animation of the wheels, etc. I never got around to finishing it.

I would love to apply the techniques shown here to the model.

_mike

#12

3 things I just want to say :slight_smile:

Firstly, unfortunately, I don’t actually think this set-up would be very easy to use in a moving train… I’ve used the co-ord system and position values in XPressionist… I’d need to make a more complicated scrip to make it moveable. That and I’m no modeller, I don’t think I’d do a very good job at making the train in the first place :slight_smile:

In case anyone wondered why I don’t post the project, I just like to see how many people are interested, and I know that if I post it some people won’t tell me.
So it’s just nice to know.

And for anyone who does see the final project, one thing to bare in mind is that for setups like this, where I’ve needed to use Xpressionist a little, NEVER use constraints… Xp really doesn’t play nice as soon as you add even a single one into the mix. Try to do everything constraint related via Xp. This also means that you can use looped constraints :wink:

#13

That train should use simple constraints… they are reliable and easy to setup. I have done similar constraint setups.

example: www.cjberg.com/movs/berry.mp4

Cj

#14

@BJMonkey
Thats it ! Why didnt you come up with this just one week earlier ? ;-)))
This would really be an interesting tutorial because that stuff can be hard to set up
for less experienced EIAS-users (like me).
Though I managed that rigging and scripting on my own meanwhile,
I guess you`re the better and more experienced tutor :wink:

@jimjam
Thats near to what I´m heading for. Im working on a close-up showing a steam locomotive starting,
with steam, sound and all that stuff.
I 3D-constructed that engine some years ago in H0 for a german model railway producer.
So I also could animate the complete locomotive in detail, but that would be a big job.
Anyway…I can post my result when I`m done.

Cheers and thanks
Tom

#15

Wow. Sorry I missed this thread. I didn’t recognize the topic and overload the author name.

I haven’t done a wheel piston but I have done plenty of pistons. I would have been happy to have assist you Tom. Basically I just used constraint’s and IK and XP if locomotion would be need to drive them based on postion.

BJ that project file would be a great post or tutorial.

#16

You`re welcome Alonzo.
With a little help and hints work is done much faster.
But on the other hand…having figured out some problems by one self makes you feel much better (afterwards…) :wink:

By the way…I enjoy your rigging DVD.
It is enormously helpful for me getting steps ahead in EIAS.
Its not only about that rigging stuff. Besides that its simply interesting to see how a professional works live in that program.
There are thousands small things to learn beside your main tutorial stuff concerning workflow and so on.

That also holds true for all the other Tutorials around, especially the Video-Tutorials.
It`s really nice to have them.

Cheers
Tom

#17 
Thanks a mill Tom for good words. 

The DVD wasn't just about rigging. It's about workflow. It was to give people a strong command of the app as a whole. I have to laugh because that was one of the goals I had in doing the DVD. It's good to know I succeeded. Thanks again.

I’m starting to work on the CD Art so youre probably the last to get for the $85 price. It’s should be going up to $120 in two weeks when I send it to CafePress. Ok. I haven’t started yet. :slight_smile:

BTW, there’s 6 pistons on the Puma robot. It’s only IK and contraints. Simple but very effective.

http://www.puma.com/holiday/

#18

Mike
Love your locomotive. It’s just what I was imagining.

Tom
Looking forward to seeing that animation one of these days.
Maybe you and Tom could help each other out?

JM

#19

Sorry.

I have no idea why my message ended up in the wrong place.

JM

#20

Hi all,

I don`t want to withhold you the results of my mechanical animation which was the reason for starting this thread.
The project once started out as a simple EI-rigging practice, but then it got out of hand somehow…:wink:
Sure there are some things that could be done better or different, here is just the state of affairs:

http://www.estudiodesign.de/show/piko/trailer.html

Be sure to have your flash plugin (6 or higher I guess) and javascript activated.
And very important…ENABLE SOUND !!!

(As always…it was hard to find a compromise between image quality and streaming capability.
Obviously I´m not a pro concerning this. The original movie looks better,
but I guess it wouldn`t stream smoothly for the most users…I hope this version is doing so)

I`m curious about your comments or reviews…and thanks again for all your hints.

Cheers
Tom