Cloth Sim

[kem]

I followed the flag waving exercise...no problem, BUT, when I created a character and try to get her dress to work via cloth sim, etc., when I get to the part where I'm supposed to pick "attached" group, there isn't one....

I added a screen shot below...

Thanks for anyone's help.

Kem

[Rodney]

There is a topic that walks through the 'Attached Group' process but I haven't used that enough to relate how that works or troubleshoot it.

A quick search of topics didn't turn that up.

 

For cloth simulation I tend to leave a set of splines/control points outside of the group that will have the cloth material assigned to it.

This locks that mesh in at those points... cloth can't simulate on control points not in the group the cloth material is applied to.

 

I've long thought I'd use the attached group option but have been satisfied enough with the direct method that I haven't delved deeper.

I'm sure others that have will share their experience and point you in the right direction for that.

[kem]

Thanks for the speedy reply. I am not new to A:M but I am new to cloth sim...and I'm not clear on the 'direct method' you speak of... Could you elaborate or send me to a topic? Thanks.

[robcat2075]

The Attach Group process has changed a bit since v16 when Jason Hampton made a video on it, but that is still worth watching if you are not familiar with Attach Groups.

 

Briefly, the maneuvers now happen in the Chor after you enable "Show more than drivers" instead of in the Objects folder.

 

I'd make a video but my voice is out today. If you are still stumped ask again in a couple days.

[Rodney]

By 'direct method' I simply mean not using additional groups as they aren't required in many cases..

Instead, group all but a few control points and use those ungrouped control points as anchors for the group you apply the cloth material onto.

 

The example of this relative to the flag exercise would be to leave the last spline closest the flag pole out of the group you intend to apply the cloth material to.

Those uneffected control points then will keep the flag in place while the rest of it gets cloth simulated.

 

 

Edit: I'm attaching an example project that contains the example of leaving some control points out of the cloth group.

Note that in the project there are two groups; a cloth group and a pole group.

The cloth... gets the cloth material applied to it

The pole... gets the deflector material applied to it.

The end of the flag that is inside the pole isn't assigned to either group.

 

 

I do believe that Robert hit the nail on the head with regard to the use of the Attached Group option.

Use that in a Choreography and it should work as expected.

Flag001.prj

[Rodney]

This is a little off topic but the thought is on my mind...

 

One of the fun things about simulation in A:M that I don't see as often as I would think might be the case is how the simulation should generally be the initial step of a number of other steps in getting the ideal shot.

For instance, after the simulation the mesh can be further altered or positioned... groups can be changed... decals can be applied.

It seems that a tendency is to use the results of a similulation as is and if it's not right... readjust settings and try again.... constantly trying to get the shot 'in simulation'.

This doesn't make a lot of sense to me especially where we might go through a set of simulated keys and extract the best ones...discarding those we don't want.

 

In the attached I've just made a few tweaks to include making the patches nearest the pole 100% transparent.. then adjusting the top and bottom control points to make them look attached while the CPs inbetween appear to be farther away from the pole. I then pasted the last keyframe over the top of the first (to seat the position and allow for looping) and then deleted the keyframes where the flag was initially dropping into place due to simulation.

 

Don't mind me though... I'm just enjoying playing with cloth again.

 

 

Also: You mention simluating a skirt or dress and the ungrouped anchors of such would likely be the top one or two spline rings at the characters waist.

The group below that would enclude everything else except that top ring. This is how I recall Nimmee Aimee's dress being set up in "Tin Woodsman of Oz".

Flag001a Sim and extract.prj

[kem]

The Attach Group process has changed a bit since v16 when Jason Hampton made a video on it, but that is still worth watching if you are not familiar with Attach Groups.

 

Briefly, the maneuvers now happen in the Chor after you enable "Show more than drivers" instead of in the Objects folder.

 

I'd make a video but my voice is out today. If you are still stumped ask again in a couple days.

Thank you for this great info. I feel like my eyes are beginning to open!

[kem]

I think I get all this, I have gone through the entire Jason Hampton video meticulously and it is quite informative...still, I can't get my model's dress to behave. It crumples up around her and goes chaotic whenever I move her at all. I'm still doing something wrong...just can't figure it out. I even tried reducing the dress spline count tremendously (the calculation before was long) and redo the entire set up, still mess... Is there a tut somewhere showing the actual process of dressing a character and animating the moves? The Nimmee Aimee thing you sent was how the flag and pole worked, which is fine, but animating the flag pole "disconnects" from the flag, so... I',m sorry but I'm still in the dark... I need my character to move and the dress according to her movements. I know when I get this I'll be elated.

[robcat2075]

I think I get all this, I have gone through the entire Jason Hampton video meticulously and it is quite informative...still, I can't get my model's dress to behave. It crumples up around her and goes chaotic whenever I move her at all.

 

If the cloth at least survives before you move the character, that is a good sign.

 

Next, go to the properties for the Choreography>Plugin Properties>Simcloth

 

Set the Collision Tolerance low.. try 1. This allows cloth to bunch together closer.

 

Set Sub Steps high. Try 20 and see if the cloth survives the movement of the model. If that doesn't work try 40.

 

Try that much and let me know what happens.

[kem]

Wow, that was awesome info. You are all they say about you, Rob, an A:M genius. The cloth is behaving MUCH better. It still crawls around her waistline and there are a few frames where her knees protrude through, but this is such an improvement.! I know you're a busy guy, but if you have any advice on the crawling waistline thing, it would be wonderful. Thank you so much.

[robcat2075]

Crawling waistline?

 

I'd have to see it.

[kem]

Well, it worked (except the waist crawl thing), I got excited, thought I'd go at it again to replicate my results...and the skirt exploded on the second frame.... I knew it wouldn't be easy and I know it's operator error...I shall not give up, though...

[Rodney]

Don't forget that if you do get a few keys that explode out of a logical position during simulation you can just delete the offending control points and use the smoother result.

Before editing the results of a simulation I do try to save the simulation first so that it can easily be returned to without simulating again.

 

This is what I was referring to above regarding endlessly tweaking a setup and re simulating versus tweaking the results of that simulation.

If for instance the waist is they only thing that isn't behaving correctly it might be worthwhile to grab those and animate them manually.

 

This is doubly true for slight crawls and extraneous movement.

Simply locate the frames where the animation looks good and then carefully remove the excess keyframes inbetween.

Copy/pasting that first set of keys to a later location (and/or peaking them so they don't have a curving interpolation) will ensure things stay in place.

 

With simulation every control point gets keyed in place on every frame.

Where possible I try to pare that down to the absolute minimum number of frames necessary.

In that way animating the shapes later via a few keys is trivial compared being nigh impossible with a key on every frame.

 

The editing of simulated data can seem quite intimidating until we remember to save the simulated data first under a specific name.

The we are free do delete whatever we want... and where we over do that editing return to the original data and try again.