# DAZ dForce vs Poser Cloth Simulation

• @fbs7 Actually Poser ALREADY does that. Poser has had the ability to use hybrid clothes for years. As per Poser's usual policy though, making hybrid clothes has always been left up to third party developers. Or am I missing what you're trying to explain.

Correct, but afaik only a body part can be dynamic. So if you have a jacket then you can make a simulation out of the bottom part of hip body part, but you can't make dynamic the seam with the chest as that would make a hole. Afaik once the cloth has hip and chest separate, there's no way to make the dynamic the whole hip plus half the chest.

That's why I said to use full body dynamics through a weight map, so that you can have hip plus chest plus shoulders dynamic in that sweater. The way it works right now is very limiting.

• I can sort of see where you could have a partial constrained area, but how could you have a partial choreographed region, either it is part of the sim or part of the animation dragging the simulation, I really can't even think of how you would use that. Also the weight painting tools in poser are pants I'd rather assign materials, groups etc.

This is how I see it:

for choreographed vertices:

vertXYZ = w * dynamicXYZ + (1-w) * choreographedXYZ

and for constrained vertices:

vertXYZ = w * dynamicXYZ + (1-w) * constrainedXYZ

So, how that works.... Imagine a long dress with sleeves. Make that all constrained; you get a simulation effect. Now make it all dynamic; you get a different simulation effect.

Both the dress fully constrained and fully dynamic produce perfectly viable meshes with the same number of vertices in the same order. Now you just blend the deltas from the two simulations using the weight map.

Now you have a dress that is partly constrained and partly dynamic, or both; the "both" means the end effect is an intermediate. That way if you make it less dynamic then the dress will not fly away if you make a sudden movement, as the constrained will anchor that. At the same time it will not have the rigid look of fully constrained, as the dynamic parts will add ruffling, oscillations and some movement on what otherwise behaves like robot armor.

Of course, a DeLuxe(tm) option is to add an animated master parameter "Dynamic Effect" that is by default 1.0 meaning the weight map is applied as specified, or another value to decrease the effect of dynamics in transitions that are too fast for dynamics, like making a 360.

• I haven't used the cloth room in Poser in quite a while, but I don't remember it being so finicky..

Here's the best I've been able to do so far.. which took quite a bit of time to find a setting that would not make it explode or crash with a simulation error halfway through it.
cloth test with animation

True, and that's a well done animation. The cloth simulator behaves better at higher fps (at least 30 fps, better at 60 fps), and with careful movements. But once you get that girl doing a cartwheel, the cloth gets completely out of control; if she does a 360 rotation then the cloth will look very wild; if she's sitting in a chair and you add collisions with the chair you'll have significant misbehaviors; and if you try to do that at lower fps then don't even consider a cloth simulation.

And nevermind if the cloth has two layers - that's just not supported, and if you try to just have two separate clothes making the layers then the outer layer will look completely finicky as the inner layer will push the outer out, but the outer layer will not push the inner back in.

Plus, good luck if you get any deformation in the cloth. Cloth deformations are plastic rather than elastic.. so once a cloth part is deformed, it's not coming back to its original shape.

I could go on with the troubles that Cloth Simulator has given me through the years, and the time I've lost with it. Nowadays I just avoid it as the plague.

• thank you Fbs.. mocap all the way, facial too. I normally don't bother with simulating clothing, but I was curious on how it worked in Daz Studio.. this animation has nothing fancy, and worked ok until the point where she raises her arms, from there on it was hell

• @fbs7 But surely you could easily write a script to do that, admittedly you would need to run two sims spawn the morph targets then merge the 2 together with a script. Not simple I agree, but if you wanted the system to work the way you describe, internally it would have to spawn a copy of the object and run a simulation on each then after it had finished use the deltas from the copy and merge them with the original, or 3 copies if you wanted everything choreographed as well.

• @fbs7 O-okay! I think I see what you're getting at, but here's the problem with your scenario. D-force isn't a Cloth simulation, it's a physics engine. So no, the Cloth simulation in Poser couldn't do that, but the Bullet Physics engine could. As for making it work more intuitively, recall that the Bullet Physics engine in Poser is a third party application, pretty much like the Cloth Sim engine. As far as I know, SM hasn't actually programmed anything in the engine for the way it works in Poser. I won't lie to you, I've watched the videos on how it works and it looks relatively easy enough, but despite what I've seen, I'm STILL uneasy with using the BP engine. That said, at least the third party that programs the BP is still around, unlike the Cloth Sim engine, so if you have any concerns with the way it works you could ask SM to talk to them or take your case directly to them for any changes you'd like to see.

• @fbs7 But surely you could easily write a script to do that, admittedly you would need to run two sims spawn the morph targets then merge the 2 together with a script. Not simple I agree, but if you wanted the system to work the way you describe, internally it would have to spawn a copy of the object and run a simulation on each then after it had finished use the deltas from the copy and merge them with the original, or 3 copies if you wanted everything choreographed as well.

My thoughts exactly! I was bored back in Dec, and I was thinking of writing a script to calculate these deltas for a full body, using a specially named texture as weight map (get uv from vertex, lookup texture, find the weight map from grayscale or something). It would need to have no collisions, though, as collisions are horribly CPU-intensive and can't do that in Python... but could have some simple spring-based dynamic effects thing.

Once one has the deltas calculated in memory, it's actually pretty simple to hook that in the display event and incorporate the deltas in the geometry for display purpose only. There's a demo from SM on that.

But in the end I thought that was more than I could chew, and didn't try it. Also the need to prepare such texture for each cloth seemed to be a big pain.

• As far as I understood is that props or objs don't work without additional effort in dforce as it still requires some rigging of the sort.

In Poser's Clothroom and VWD, you can just get an obj simmed.

• @fbs7 But if you can't do collisions then it isn't really a cloth sim, as the whole purpose, other than draping curtains is the collisions with the wearer and other objects.

• @fbs7 But if you can't do collisions then it isn't really a cloth sim, as the whole purpose, other than draping curtains is the collisions with the wearer and other objects.

I was thinking of just giving a shuffling or shimmering effect to what would otherwise be a conforming cloth. But that would work for small movements only.

• @fbs7 has anyone determined the file format for the cloth dynamics files? If so, it might be possible to use a weight map and python script to generate a second dynamics file with modulated dynamics. Perhaps. Depending on whether the file distinguishes dynamics from choreographed vertices.

• @anomalaus The file format is object files, same as always for both the Poser Cloth Room and the BP engine. Weightmaps would be of little to no use in either the Cloth Room or BP.

• @eclark1849 no, no. I don't mean the .obj wavefront object geometry definitions, I mean the .dyn dynamic cloth simulation files, which must contain per-frame-per-vertex deformations for the dynamic cloth object for the whole simulation. The .dyn files are a binary format, like (but not the same format as) .pmd, not human-readable text, like .obj files (or even the gzip compressed .obz files).

• @anomalaus From P11 onwards the extension is now .abc and they are I believe alembic files

• @anomalaus
I have understood these files use the in Alembic format.
(@amethystpendant did beat me by a minute on this one, LOL!)

• @amethystpendant & @fverbaas thanks, it's been that long since I ran simulations regularly, and since I'm now using autosave, the simulations get hidden away in subdirectories. I am seeing .abc Alembic files for the most recent cloth simulation.

• I wouldn't touch the cloth simulation files with a 50-feet spear... the thing already breaks a lot on its own without external help...

• @fbs7
It seems VWD uses these files to communicate with Poser.

• @fbs7
It seems VWD uses these files to communicate with Poser.

Haven't played with VWD since it was launched, really must! But yes the proc calculates the sim and writes the results to the alembic file so that Poser can apply them