Basic Rigid Body question

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

Subscriber
Join Date: Sep 2004

Location: Queens, New York City

Posts: 367

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..."

Quote

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

Moderator
Join Date: May 2005

Location: Manchester Uk

Posts: 6,300

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)

Quote

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

Subscriber
Join Date: Sep 2004

Location: Queens, New York City

Posts: 367

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..."

Quote

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

Moderator
Join Date: Oct 2002

Location: London, UK

Posts: 2,800

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.

user added image

Attached Files

cubeonsurface.ma (123.3 KB, 355 views)

Technical Director - Framestore

Currently working on: Your Highness

IMDB

Quote

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

Moderator
Join Date: May 2005

Location: Manchester Uk

Posts: 6,300

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

Quote

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

Subscriber
Join Date: Sep 2004

Location: Queens, New York City

Posts: 367

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..."

Quote

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

Moderator
Join Date: Oct 2002

Location: London, UK

Posts: 2,800

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

user added image

Technical Director - Framestore

Currently working on: Your Highness

IMDB

Quote

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

Subscriber
Join Date: Mar 2005

Location: London

Posts: 1,135

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

Quote