Carrara physics: animated forklift on uneven terrain

argus1000

I played with iClone's physics toolbox. You can do (and export) wonderful things with it. This video, which is just a quick test, shows an iClone physics-animated forklift on the move, but rendered in Carrara : the wheels keep up to speed and follow the terrain, the forklift itself goes up and down, left and right, etc and the load is physics-animated as well.

http://youtu.be/kQwGyE2mjh0

However, it's a pain to export all this to other software. Besides, one exported, the results are not as good. With its bullet physics, Carrara should be able to do this. But it seems so much more difficult in Carrara. Anybody got an idea on how to proceed?

evilproducer

Sparrowhawke has a couple free plugins that may help with this.

argus1000

I know about Sparrowhawke's plugins. I'm interested in bullet physics. You can do so much more with it.

evilproducer

argus1000 said:

I know about Sparrowhawke's plugins. I'm interested in bullet physics. You can do so much more with it.

You didn't specify a physics only solution. You mentioned you had some issues with the imported iClone simulation and you wanted to know how to get better results. I have no idea what plugins you do or do not know about. Sparrowhawke was my suggestion for the tire rotation, and it still is.

A hybrid solution may be the easiest way to go, plugin for the wheels, and physics for the load. It's your animation, so it's up to you what method works best for you.

Good luck!

tbwoq

Some suggestions using only Carrara...

1.The forklift following the terrain probably needs to be keyframed;

-Select the forklift and use the scene collision(icon at the top of assemble room).
-Move the forklift and manually collide it at points along the terrain in the timeline. This works for a motion path method also.

2.Spin modifiers for the wheels.

3.Bullet physics for the load on the forklift might work depending on the animation of the forklift.

Bullet doesn't have any type of rag doll physics in Carrara yet. Only a type of softbody attach. So this is why most of it might need to be keyframed. If it did have rag doll collision, you could simulate the forklift along a terrain and have the wheels, loads and shock absorber effects.

Bullet and Standard physics have very poor collision detection against any non-physics animated objects. For instance. A swinging bat(non-physics) hitting a baseball(physics) doesn't work very well in Carrara(etc.). I can give more info, or more suggestions from testing later if needed.

argus1000

tbwoq said:

A swinging bat(non-physics) hitting a baseball(physics) doesn't work very well in Carrara(etc.). .

Maybe using physics on the swinging back also? As for ragdolls, I don't see why it would be impossible in Carrara. As the still pic indicates, some users have succeeded in building a quite sophisticated ragdoll in iClone with physics-enabled simple cubes (the orange cubes are stabilizers). I don't see why this would be impossible in Carrara at this time.

Evil producer is right in saying that in Carrara only an hybrid solution is now practical. And Tbwoq is also right in suggesting to keyframe the forklift on a path, with a spin modifier on the wheels. Of course, this doesn't take into account the shock absorbers and the load.

As you can judge by my second example from iClone's "physics toolbox" (check it out), only physics, IMHO, can be totally realistic as far as depositing the load on the ground. This would be hard and tedious to keyframe.

http://youtu.be/lgW36wg6jfs

All in all, with bullet physics, we see a lot of tutorials of cubes hitting other cubes, but few tutorials about practical situations. I wish PhilW or Mark Bremmer would publish a DVD on bullet physics in Carrara with real world examples. I would buy it.

Dartanbeck

Cool forklift video. I like how the wheels spin first, then it starts to move.
Okay, nearly unrelated... did you take down your movie? It's not there! >:(

argus1000

Dartanbeck said:

Cool forklift video. I like how the wheels spin first, then it starts to move.
Okay, nearly unrelated... did you take down your movie? It's not there! >:(

I have 2 Youtube accounts. One for tests like this forklift video (argus10000) and one for finished movies (argus1000bis).

I have another movie coming.

tbwoq

Hi argus1000.

Carrara's physics can't have initial contact/touch at the begining of a simulation or the collision fails or pushes those objects apart depending on settings. Because of this, theres no way to connect or pin down physics method objects to other objects. So a baseball bat(physics) a figure is holding would fly out through the figures hands before the swing. Though by itself it should work and then have the figures hands maybe track it after. But this is alot of extra work verses keyframing manually(imho).

The Soft Body Attach modifier can attach to objects, but its not setup at all for ragdoll physics. If it did work, the next problem would be having another figures arms, torso, legs, head etc., track each of the physics parts in a ragdoll way and without the soft body part hotpoints having issues(they move unrealistically). There is also the issue of where in the animation you need the ragdoll physics to occur. You may have to convert physics back to keyframes method for this(etc.).

Ragdoll physics or setting up similar physics in Carrara isn't impossible, just very very difficult under the limitations the physics have atm. Now that C8.5 is released, hopefully there will be more physics tutorials for Bullet physics.