dear all,

although I've figured out most of the Dynamic Cloth features and issues, read the forums and tutorials and what else is available, I still run into a battle I can't win. Suggestions, hints and everything that contributes is very welcome.

The bottom line is: while building the simulation, dress vertices go wild and scatter polys all over the place. Depending on the cloth parameters, the first 10 to 20 frames go very well but in some settings even that is not the case.

In my quest, Vicky performs a (18 sec) animation (@25 fps = 450 frames) which does contain some fierce poses, all within limits and physically okay, starting in T-pose at frame 1. Moves are slow and gradual. She's wearing a long summerdress, which fits properly especially on the top half. The skirt is long and wide (flamengo-like). Since conforming does help with the top-half but hardly will give satisfying results with the skirt part, I turned the dress from conforming into dynamic.
I tried the OBJ export/import route as well as the Wardrobe Wizard route, both have their pros and cons but neither helped me out.
I tried various parameter settings, some for the better some for worse, neither helped me out. The very top portion of the dress is put in a Constraint group, it saved the dress from falling off but it did not help me out.
I start the simulation with a multi-frame drape. It doesn't help me out, and only shows that the dress fits properly. It even deals neatly wind extras like wind force. 
I fiddles with the Collision Offset, and checked and unchecked the vertex and poly collision checkboxes. Collision check is set for body and legs till toe, and the collar but not the arms as the dress is without sleeves.

Please help.

 Can you show us some screens?  It makes it a lot easier.

If you have converted a conforming dress , here is a test I do. Set up your cloth simulation with the dress only at frame 1 . make a choreographed group with only a few polys at the top of the dress. Run the simulation for 30 frames or so. If the dress falls apart then it wont work without some changes to the obj.

A picture of cloth room settings and the broken dress would be helpful.

thanks to Grappo2000 and Markschum, who stimulated me to reset all parameters and recheck everything again before making examples. And hey, it solved the issue!

But I don't succees in getting an image in the post, what do I have to do for uploading? So I just attached a file (jpg). Sorry.

With all cloth parameters still at default, the simulation settings I used were

good for producing the broken dress (middle, left).

But I managed to turn this into the okay dress (middle/middle), and even wild jumps (middle/right) got supported, while the whole animation runs quite well actually. The 450 frame sim took about 7 hours to compute and still isn't perfect, but at least I've got a working sim to take me further.

The magic bullet? Just switch ON the middle option, poly versus poly. 

You apparently need it when the object (Vicky) has a quite higher density poly / vertex mesh than the cloth (Dress), making vertices to go well but polys to peek through anyway. That can be caused by the conversion routines like export/import or Wardrobe Wizard (... As Prop), I guess these try to optimize their result and reduce mesh density. Very good, except for cloth sims. 

I'll put this in a tutorial (like I will with the lighting. Do you like my softbox setup?)

I'm glad you got it working. :)

 Btw, that's very nice dress, which one is it? ( like converting conforming clothes to dynamic too)

It's Benefit Gala for V4 by Ryverthorn from RDNA.
It's still there for $3 (http://www.runtimedna.com/Benefit-Gala-for-V4.html)

I like the original blue/purple texture the best, but I have to figure out why converting it to Prop via Wardrobe Wizard did make the texture mapping go bust. In the meantime, she's got the Poser colorramp default texture following the V-coordinate upwards.

Regards