hi all,

I continued my strolling around the Net and in the end I found myself buried deep down in a worldwide scientific community on cloth simulation, US patents included, which evolved from about the mid '80s. That was about the moment I stopped in the scientific arena after getting my MSc on applied math and experimental physics. I never looked back. This means to me that I will stop looking further into this area on the vertex level. Back to the front! But I'll give you what I found on the ways forth and back.

From the saved pages from poserfashion.net I learned that the author (Serge Marck) was into cloth sim long before Poser started doing it. He stated that all cloth sim routines (those days) were based on the modeling of physical fibre behaviour in cloth. His main source was a tutorial by P.S. Karthikeyan. More on that later.

He also flagged and demonstrated that because of this, the simulation results depend on non-virtual things as real world cloth size and structure. In effect, he showed differences (from Cloth Room) based on cloth size at constant vertex density, on vertex density at constant cloth size, and on mesh type (quad vs tris) at constant density and size.
This implies to me that the mesh structure (and not the vertices only) is mapped onto an internal (fine grained) cloth representation. From that, layered ball/spring nets are deployed to run the sim, and then all this is translated back to vertex positions (and speeds?) in the cloth mesh. Things might get lost in translation.

Serge Marck also noted that since the Dynamics experiences in the Poser community were very thin those days, it could be an advantage to look into the forums of other applications, like ClothReyes, Stitch and SimCloth.
This last one is quite interesting, as it's an Open Source plugin for 3DS MAX, in its final state since 3DSMAX 3 (that's before the Poser Cloth Room) and only recompiled after that, and still here for 3DSMAX-2010. I also found references to SimCloth for its use in large scale movie and TV-series productions, in 3500-figure crowd shots. So, its code and docs can tell us something, I guess. 

Back to the tutorial. It's nowhere nowadays, I only could find a Russian translation of one chapter out of it, on the modeling fundamentals. This said that all started in the '80s from the well understood behaviour of cables (hanging bridges, telegraph cables) and the effects of fibre parameters, the effects of fibre thickness on those parameters, and the effects of gravity and wind (those two again!). Cloth then is interpreted as a two-way weave of cloth fibres each described with cable behaviour.

It also said that - at those days - P.S. Karthikeyan was a 3rd year student on the Aerospace Institute in Madras. I did not find any other refernces to him related to cloth sim, after that. But I did find that the tutorial must have been very good, because it's quoted in about every paper on this matter from those days on. Google rocks.

One of the papers I ran into looked worth downloading and sharing, it looked readable, an overview on fundamentals and implementations in the popular cloth sim software mentioned above and in previous posts. Recommended.

It's http://www.risc.jku.at/publications/download/risc_2354/manasilib.pdf 

Then we are into RISC, deep down the science dungeons. Get me out!

So, one way or another, the mesh structure is mapped onto a simulation of cloth physics based on fibre material characteristics, fibre thickness (which effects stretch and bend etc all in different ways) and weave/knit tightness. Poser does not grant us access nor insight to any of this.

With respect to all of this, Cloth Room definitely is a different beast than Materials Room or alike. It's not a Room at all, it's the Magic Kingdom Castle, or the complete Disneyland Park around it. I'm back to the front gate. See you there.

- - - - - 

Usually I'm wrong. But to be effective and efficient, I don't need to be correct or accurate.

visit www.aRtBeeWeb.nl (works) or Missing Manuals (tutorials & reviews) - both need an update though