crawlertracks get launched upon (re)simulation

[jojo]

i fully rigged a tank in 3dsMax2009, with the extra wheels, crawler, crawler track and cogs.

but when i want to resimulate the tracks after i drove around, the tracks get launched in the air in the first 2 or 3 frames,
looks quite funny though, like a small rubberband

anyways, is there a way to fix the launching?

[jojo]

after rebuilding the rig (in a seperate scene) i got it to stay on, but only for a very limited time,

when i increase the tracks "accuracy" or "substeps" they only get launched sooner!

Does anyone have a good crawlertrack 9wheeled (abrams style) profile to use on the tracks maybe?

[jojo]

here is a screenshot of the flying off one frame before it flies of.

you can clearly see that the tracks just penetrate the wheel

*its hard to see, but i have cogs in the front and in the back, so the orange wheel is also being driven

[Carl Buhre]

There are a few things you can do in order to avoid this. One would be to put the tank closer to the ground. If the tank is a bit up in the air at the start of the animation, its wheels will "hit" the ground when it gets its animation and if the distance is too great when that happens, it will cause the tracks to flip out.

Another way of doing this, is to first record the tank minus the tracks (everything checked except Craft CrawlerTracks) so it gets its animation first. Then move the time slider to the point where the tank has hit the ground and is ready to go. Go into the configuration of Craft CrawlerTracks and create the tracks in this time position. Once the tracks have been created, resimulate them to create the animation but do it from the point where the tank has hit the ground, not the start of the animation.

Please let me know if this helps.

[jojo]

thanks ill go try that.

btw, are there any other tricks to stabilize crawler tracks even more?

[Carl Buhre]

thanks ill go try that.

btw, are there any other tricks to stabilize crawler tracks even more?

One thing I'm sort of noticing from your screenshot is that you didn't leave much gap for the tracks. When you create the wheels for Craft CrawlerTracks, you should try to make them smaller than the wheels that are driving them. Try to give them the diameter of the wheel that's driving it, minus the height of CrawlerTracks_01_TemplateStep, preferably even smaller so that there's some play.
This is done to keep your crawlertracks wheels from pushing the track through the ground, causing it to flip out.

I've created a gif animation to illustrate the gap, I hope you see what I mean. Please ask if you want me to elaborate on this.

[jojo]

you should try to make them smaller than the wheels that are driving them. Try to give them the diameter of the wheel that's driving it, minus the height of CrawlerTracks_01_TemplateStep, preferably even smaller so that there's some play.

Doh!

working like a charm now!

btw, i want the tank to go over a sharp edge of a hill, is it possible to let the tank tracks partially come loose of the ground, and then pivot down hill?
(like the Leclerc tank does in this movie http://www.youtube.com/watch?v=xj4jGgQCuFw)

[jojo]

another little problem i just came acros is that the suspention of the crawler is acting strange,

the body sways forward/backwards/sidewards when i make turns or external force is applied, but it doesnt "recover" it stays in the same position until force in another angle is applied.
is there a way to improve this? (aka what values to tweak best to what values?)

[Carl Buhre]

you should try to make them smaller than the wheels that are driving them. Try to give them the diameter of the wheel that's driving it, minus the height of CrawlerTracks_01_TemplateStep, preferably even smaller so that there's some play.

Doh!

working like a charm now!

btw, i want the tank to go over a sharp edge of a hill, is it possible to let the tank tracks partially come loose of the ground, and then pivot down hill?
(like the Leclerc tank does in this movie http://www.youtube.com/watch?v=xj4jGgQCuFw)

You might be able to "fake it" by manually keyframing the chassis relocator of Craft Crawler. Key frame it so that it looks like the tank is jumping, then resimulate just the tracks to get their new movement. I can't swear this will work though as I haven't tried it myself.

[Luigi Tramontana]

Also you should take a close look at the tank rigging video tutorial: http://www.craftanimations.com/index.cf ... F735792452
It's created in maya but since our tools are host application independent exactly the same principles are used in max. Here you will see how to use extra wheels to create the effect you desire.
When driving over sharp edges you should also use the RayMultiplier parameter to improve the interaction with the ground obstacles.

Regarding the tracks staying in place I believe has to do with you following the manual, and on point 20 you are supposed to parent/link the CrawlerTracks' "Frame" to the chassisRelocator of the Crawler. This was necessary earlier due to stability issues, but it is perfectly safe now to keep the Frame unparented/unlinked, ie keep it in world space. If you link it the tracks will live in the Tank world and will not notice it swinging and swaying in the world.

[Enigma229]

You know would be nice? A downloadable max/maya file of the basic CrawlerExt-CrawlerTracks rig. Very similar to the video that Carl created. For some reason, I can't get my tracks to work on a simple rig like the one in that video.

[j.lennon]

Hi jojo!
If you want to make a tank jumping, I think you can use this way:
You do like Carl do in his tutorial about Rigging a Tank, but at the step "create a CrawlerExt" you create a 4WheelerExt . So when you use 4WheelerExt intead of CrawlerExt, you can go to configure menu and check Enable Jumping in the Jumping parameters.
I did it, and the tank jumping up, but the track go crazy. I think the reason is the speed( I set the Gal Pedal=10) so the track not run correctly. I'm trying to fix that. If you fixed these track help me!
My english very bad, hope you understand it. Thanks alot.

[Luigi Tramontana]

In physics simulation increasing the fps is the same as telling the simulation that the world moves in slow-motion.
So if you crank up the fps temporarily, say 10 times, you should be able to control the missbehaviour.

[mitul087]

Great! Thanks for your post.
simulation emprunt immobilier