Basic Rigid Body question

# 1 23-09-2006 , 05:58 PM

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I have been concentrating on modelling, rigging, and animation and have had precious little time to fiddle with dynamics (OK, I created lightning and fire, but...).

I've tried this before with no luck. Basically, what I am trying to do is to get a cube to travel over a "hilly surface", as if the cube were a tank and the nurbs plane was hilly ground.

It would seem easy. Create a cube, create (and deform) a NURBS plane; make the cube an active rigid body and the plane a passive rigid body. set a few parameters, have the cube travel in the "Z" direction, and that's it. Oh, yes...I also know to set the timeline to "Play Every Frame".

Every time I try this nothing happens. Most of the rigid body tuts I've seen deal with things like bowling pins, &c. I don't even want to get that complex!

In the end, I hope to make the cube a proxy object for a tank model, which will hopefully negotiate the "hilly" NURBS object.

My "workaround" is to animate it all by hand without dynamics.

ANY LEADS?? :-)

Thanks in advance! :-)

"Ad astra per aspera..."

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# 2 23-09-2006 , 09:07 PM

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I'd give particles a go, create one particle and instance your cube to it then use fields to moe it over the surface (with the particle colliding with the nurbs plane but with very little "bounce" to it to stop if flying off)

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# 3 24-09-2006 , 12:52 AM

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Thanks, Gster, hadn't thought about that! :-) I think the idea is to use the cube (or whatever shape) as a proxy object (parented to the actual model which remains invisible until render time). Now that the hard part of my reel is finished (about three minutes of character animation), I will have time to figure all this out!

Again, thanks! I will let you know what happened!

"Ad astra per aspera..."

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# 4 24-09-2006 , 01:49 AM

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you don't need particles at all. You can do it very very easily with a geometry and normal constraint. have a look at this scene file. Play the animation to see what I mean.

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cubeonsurface.ma (123.3 KB, 262 views)

Technical Director - Framestore

Currently working on: Your Highness

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# 5 24-09-2006 , 02:13 AM

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Cool, didn't think of using a constraint, Just was the first thing that came to my head to solve the problem.

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# 6 24-09-2006 , 02:16 AM

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Pure Morning,

I couldn't get the file to load (I'm using 6.5, maybe that's why). Nevertheless, if constraints will do the trick I will go ahead and start experimenting.

Thanks again to both of you for your advice!

"Ad astra per aspera..."

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# 7 24-09-2006 , 02:30 AM

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just go into the file in notepad and edit the first few lines to say maya 6.5 rather than maya 7.0.1

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Currently working on: Your Highness

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# 8 24-09-2006 , 05:15 AM

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i know this is more of a basic approach but it will work however it will limit the animation

make the nurbs surface live draw a curve on theere where u want the cube to go

make surface not live an duplicate that surface curve an raise it to the approiate height an attach the cube to it as a motion path
now the cube will follow the contours of the ground
also u can key in rotations an speed

just another option to be put out there

Now at SMU doing BSc 3D Computer Animation so its hard to get on here
My wire render tut https://forum.simplymaya.com/showthre...threadid=20973

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