Caterpillar Track Development - No Physics!

[clockmender]

This WIP is all about how I have developed a caterpillar track system, using Animation Nodes and Clockwork Magic. There are some of my own nodes in the node tree, but nothing that cannot be replicated using Script nodes and Expression nodes.

Here are some images of the model:

On this first one it is fitted with a missile battery. :eyebrowlift:

On this second one it is fitted with a turret and gun., self targeting of course, now I know how the army do this with their tanks - a simple IK chain. :eyebrowlift:

Finally, it has just driven off a crest at hight speed and is in the process of rejoining the ground!

So, the challenge was to provide a system that does all of the following:

• Vary track speed when turning a corner.
• Turn on the spot, so spin about the central Z axis.
• Go forwards and backwards along a curve path.
• Switch from one curve path to another.
• Provide an automatic suspension system.
• Provide an automatic spring compression system.
• Provide automatic tilt, or roll, along the transverse and longitudinal axes.
• Leave Terra Firma and return without the wheels exceeding the suspension’s maximum travel.
• Provide a track tensioning system that varies as the wheels move on their suspension.

Some of the above proved to be difficult to say the least, but I hope I have shown in the first few images that these have been achieved. So the thread will describe how I did it and the problems faced, including all the issues that have been discussed at great length on many threads in the Animation and Rigging section of BA. :spin:

I have had to write only one complex node, that cannot be replaced with either Expression nodes, or other nodes, etc, but could be done with a Script node. This is the bit that moves the track pads around. For this I had to use frame-by-frame delta movements, something you can do with AN, but by no other means that I have found so far.

I know about Physics, but solutions based on this were too imprecise and too hard to control exactly for my requirements, so this is the result of my extensive research and development. There are many videos on my YouTube channel that show the development and more will be made in due course.

So I hope this is of interest and you will forgive me a few moments of madness and humour along the way. :eek:

Cheers, Clock. :eyebrowlift2:

PS. I am now knackered, so the next post, which will describe the start of the process will follow in a day, or so. Now where’s my bloody JD bottle… :evilgrin:

[clockmender]

Having built around fifteen models in the development phase, as detailed in the Animation & Rigging thread, I decided in the end that the best starting point was the anchors, or fixed points for the track curve. The tracks are made with a simple plane object, which is then given Array and Curve Modifiers. I then make a detailed pad and parent this to the plane object - this ensures that the track pads are not distorted by the curve as would be the case if I used a Curve Modifier on the pad itself.

The fixed points for the track curve are the top rollers, front roller and drive gear. The floating points are the road wheels and the tension points between the top rollers, front rollers and drive gear, these will move as the suspension is operated, so here is an image of stage 1:

This assembly has six road wheels, three top rollers, one drive gear and one front roller on each side. The rollers and wheels are different diameters, so each set on each side belong to individual object groups. There is one group of wheels and one of the rest per side making four groups in total. The size and tooth spacing for the drive gear is fixed by the size of the pad so there is an integer number of teeth on the gear. I calculated the size of the gear by taking the pad length and multiplying this by the required number of teeth, then I calculated the chord length of one pad and from that the circumference of the gear and from that the radius. This makes sure that the teeth always engage in the slots on the pads.

Here is an image of the pads and gear:

You can also see the spring, this will be dealt with later on. The rollers, gears and wheels all have features that allow you to see them rotating - its a bit pointless to rotate them if they have no features! Next we will deal with the armature to control the position of the track path curve and road wheels. This present some problems in getting the curve to behave and stopping the wheels dropping too far if the tracks leave the ground underneath them as illustrated below:

I have lifted the tracks off the ground and they have not dropped more than the permitted suspension travel.

Cheers, Clock. :eyebrowlift:

[GrimZA (Armand)]

Nice work.

I’ve also messed with tank tracks in the past but haven’t fiddled with suspension much.

Attachments

Tank 4.blend (6.07 MB)

[clockmender]

@GrimZA: Ah yes, the Physics method, I cannot get my head around this yet, maybe I am missing something.

Anyways, here is a video of he suspension system in action on a very simple model:

Can anyone “Name that tune”?

And the Armoured Bridge Layer:

With the bridge deployed:

I wil explain the armature tomorrow, if I can find some time amidst all that Mrs. C want me to do. :eyebrowlift:

Cheers, Clock. :RocknRoll:

[clockmender]

Of course what works for tracks also works for many wheels: :yes:

Even on corners and uneven ground with two steering axles: :yes:

Node Tree to do all that: :eyebrowlift:

I’ll try to explain the armature tomorrow, I got too busy today…

Cheers, Clock. :eyebrowlift:

[Estajxo]

In German there is a saying that translates like: “That fits like the fist onto the eye!” That’s what I think of when I hear the music to your videos…

Apart from that, it is looking really good. Also, I notice that you left the world of rigging already far behind and have quite some nice modelling here. Can we see the bridge builder in action, maybe? :eyebrowlift2:

[clockmender]

I think we have lost a couple of posts in the migration process, so I will play “Catch Up”:

First there was this video:

Armoured Bridge Layer - The First Cut

The there were a couple of pictures:

and:

And some meaningless drivel from me about rigging this beastie above. I think I also droned on about copyright issues on my videos, that nobody is remotely interested in, so I won’t repeat that. I have done some more work on the bridge layer and am cooking a new end to the video, showing the bridge being deployed, here is the latest image:

More once I have cooked the video and made some progress with the wheeled vehicle.

Seen on the bridge with the machine gun on the top, well little things amuse little minds.

I like the new website, thanks to all involved in this wonderful work.

Cheers, Clock.

PS. Billions of emoji to play with, where does one start?

[clockmender]

Well, what can I say; 16 wheel automatic steer, 16 wheel independent suspension, I can retire undefeated, just got to connect all the meshes up and make an uneven ground to prove the point:

And a render:

I will continue with this and the other things after a good days flying tomorrow, yes I am off to play with my '63 K8B All the emoji and I cannot find a “pilot” one…

Cheers, Clock.

PS. Does anyone want to know how I did that?

PPS. I can make either the forth, or fifth axle from the left non steering, or both steering proportionately depending on how drunk I am…

Like so, I just need to move one bone (the high-lighted one):

[Estajxo]

Really interesting! At first I thought the bridge builder tank was just a crazy idea of yours, but I just looked it up and was surprised to see that they are real!

Sooo… after your latest 16 wheel steer, what comes next in your adventurous Blender journey? A fully rigged centipede?

[Gumboots]

Very cool. Although I think the original 16x16 beast only had steering on the front four axles, so you could have saved yourself some work there. But then, it’s probably more fun to show off.

And don’t get me started on the emojis. There are so many of the buggers that I can’t even be bothered looking through them at all. I’ll just go back to typing age-old smiley punctuation, and if it happens to show an emoji I’ll call that a bonus.

Hey, that one works.

[cadaei]

The progress here has been really fun to watch!

I’m still working on my physics versions, mainly because it’s fun. It seems that most of the stuff I do in blender ends up being just out of curiosity on how to solve a particular problem, and I never end up making any fancy animation/render from it.

It does seem like there should some simpler solution for someone who just wants a simple track solution.

[clockmender]

Hi Chaps!, just sneaked out of a family dinner - bored shitless, so hope I don’t get caught skiving.

Here is the 16 wheeler, from what I can tell, all axles steer now:

and a bit more:

I am not sure about earlier versions, but every video I can find on YouPorn shows all axles steering.

@cadaei ; I think that tracks can be done more simply, but they don’t work properly, or look like they are skidding and sliding and bouncing too much any other way I have tried.

BTW, the next videos are nearly ready, should be able to post them tomorrow.

And yes, Armoured Bridge Layers are real! there are many versions based on Challenger, Leopard, and all sorts of other tank bodies. Apparently you just cut the turret off and bolt a few brackets on to hold the bridge parts…

BTW, you are right @Gumboots, there are far, far, too-effin’ far too many firkin’ emoji and not one “Pilot” one, while I am having a rant - where have our signatures gone, I was particularly fond of my old one, especially the bit where @Gumboots says I was “completely bonkers”.

Oh shit, Mrs. C is asking where I am, gotta go!

Cheers, Clock.

PS, Just given Mrs. C the slip, it is definitely more fun to “show off” what you can do with an armature and a little patience, teehee

[Gumboots]

Discourse no haz teh sigz. Teh siggys ist verboten. We are in brave new world now, and we will be happy. If you are not happy, you will be shot. Welcome to glorious worker’s paradise.

[clockmender]

Yar, vee vill be tolt vot to do!

So, here is the latest video of the Armoured Bridge Layer:

I have recorded the whole animation on one camera then part on a second camera at the end of the video.

I have rendered the 8 wheeler to png files, just need to process to video, but Mrs. C is wanting me to do some woodwork in my workshop, so it will be later today I think.

Cheers, Clock.

[clockmender]

So I went to our local branch of ICBMs “R” Us and found this for the 16 wheeler:

Next I really must upload the 8 wheeler video, but I am seriously knackered now so it will have to wait.

Cheers Clock.

PS. Can we have a contest to find the most inappropriate use of an emoji?

[clockmender]

Here is the video, Mrs. C has made me a cup of tea to revive me, she is so kind (most of the time).

8 Wheel Vehicle -1

Cheers, Clock,

Oh no! I have been rumbled for using Prince’s tunes:

Back to my own stuff then…

[Gumboots]

ROFL @ “ICBM’s R Us”. If bloody Trump gets his way, that might be a new US sideline. He’d sell anything for the sake of a “good deal”.

And now I want to see a video of you on stage singing Raspberry Beret. Or on top of an ICBM carrier. Either would work.

[Speed7]

If there is one thing I do like about the new forum it is the puke emoji.

Just need the bashing head against the wall one now and life is complete.

[clockmender]

@Speed7 - Hi Shaun, yes I think the puke emoji will get a lot of use…

@Gumboots Trust me you DO NOT want to see me, let alone hear me singing, that would be too much torture for any person.

Update, before I go away for a long weekend in Sweden:

Someone is about to be in seriously deep doodoo

Cheers, Clock.

---

My Signature:

K.I.S.S - A good maxim I think and Granddads know best.
My YouTube Crap , My Silly Website
@Gumboots: “You are completely bonkers!” - I agree with him

[Speed7]

Clock , where are you, you said long weekend, that’s more than a week ago, does the disappearance have anything to do with Maja?

Best Shaun

Edit: My oh my Clock, thats a big rocket you have there!