New Tutorial on Cloth & R12 Dynamics

#1

Hey guys, just posted a new tutorial covering some integrations tips for using cloth & Dynamics together. Link

Cheers,

Josh

#2

Hi Josh,
just skimmed through the tutorial, looks interesting. Concerning the collision lag though, it’s not a collision problem but a priority problem. We cannot control the cloth or the dynamics tag priority value, but if you bake the rigid body dynamics it should work properly.

#3

I thought it was a priority issue but couldn’t find a way to change the priority value and I tried baking the rigid body dynamics previously and that didn’t do the trick. Please post a file if you get it working correctly.

Here’s some of simple files to play with. link

Thanks for watching.

Cheers,

Josh

#4

I see, the problem is also the clothnurbs. Cloth dynamics have a priority I[/I] after generators, they are designed this way so they work them, but that means they will also lag 1 frame if they are placed in a generator and not baked.

So if you want to apply a clothnurbs, baking the rigid body is not enough, you need to also bake the cloth in order not to lag.

By not baking either the rigid body (should be baked first) or the cloth, the cloth simulation will lag 2 frames in the viewport.

Here’s a file with the simulation baked: http://dl.dropbox.com/u/14537088/Cloth%26Modyn_0002.c4d.zip

Edit: Also here’s a trick for non intersecting without baking, I made a copy of the sphere that lags 2 frames behind and hidden the original sphere. Though I would not recommend it since if you bake the cloth, then it will go 1 frame ahead (since it will have no lag from the clothnurbs). But I thought it might be interesting as a test :slight_smile: http://dl.dropbox.com/u/14537088/Cloth%26Modyn_0003.c4d

#5

Excellent 51MON, that did the trick ;). I’ll be sure to update the tutorial and give you credit! This is precisely the reason I posted my R&D stuff you never know who has gone down this road before and may have an answer. Thanks.

Cheers,

Josh

#6

I’m glad I helped. :slight_smile:
Cinema’s priorities can certainly be confusing like that.
Also, I made I mistake above, the cloth’s priority is after the generators, not before them, I corrected it.

#7

For sure. I remember the first rig I built. All kinds of priority fun. Yeah, I noticed no problem I knew what you meant.

Cheers,
Josh

#8

Hi,

interesting topic. To further add to this discussion, dynamics is exactly executed on Generators 400 level. That means everything that should happen after dynamics has to be set to an execution level higher than 400. Although I see why this decision was made (to allow for dynamic MoGraph objects) it’s not very clever. Hair dynamics can be set to be executed at every point in the execution list. The new dynamics cannot. Bad thing.

To get around baking, though, you could do a dirty trick. Animate your sphere with dynamics. Then copy it and wire the copy to the original using an Xpresso tag and the DynamicBody node. Now you can set the execution priority of the Xpresso tag. This will lag behind the original dynamics simulation, but as you can hide the original object you’ll get a matching animation without baking.

Unfortunately this is not practicable with a lot of objects. That’s why a typical dyn setup has to be baked up to 5 times during the setup process. I hope this behaviour of dynamic will be changed in the future.

Best Manuel

#9

Interesting read Manuel. Thanks for posting.

Cheers,
Josh

#10

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