dForce exploding content - possible work around?

Wouldhe

I'm a very casual Daz user but dForce looks interesting so figured I'd play with it.  With 1 or 2 exceptions, pretty much any content I tried resulted in exploding content and / or Daz hanging and into task manager to kill the process.

I figured if it works with a primitive it may work with a plain object.  Exported a V4 item (that had previously crashed and burned) and re imported, applied the modifier and tried dropping it onto a plane - seemed to work fine. After a bit of blundering around, got the object rigged and converted to a figure, dressed genesis, applied the modifier, posed the model and simulated the drape.  The result is every bit as good as anything I managed with dynamic clothing previously.

I can't say it's a solution based on 1 test but, for what it's worth, may make dForce draping available for products that otherwise don't work.

IsaacNewton

Are you suggesting that the V4 rigging on the clothing was causing the strange results? If so, your process should work with any single mesh object. I must give this a go.

cdbernier

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Richard Haseltine

cdbernier said:

This seems like the best place to post what I have experienced. I prefer to work in NPR (Non-Photo Realistic), so 3Delight is my go to render engine. I was also thrilled when dForce was released, but that turned sour quickly because everything I tried to simulate exploded, refused to initialize, or crashed Studio. I wondered if there was a connection between 3Delight and iRay shaders to dForce. It seems so. The simulations work with iRay shaders, but they do not work with 3Delight. It's possible that older content may simulate better (barring unwelded mesh issues) when iRay shaders re applied. I'm posting examples of my experience ... G8F with Barot top and skirt (note that the Bardot outfit is a dForce compatible item, and no changes were made from the default load settings).

Although the settings for materials use the Surfaces pane they are not connected to shading or rendering. Could you give the exact steps you are using (Bardot loads with iray sahders, so if you are doing something to get to a 3Delight material it may be affecting the dForce settings too).

cdbernier

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mephoria

I attempted to do a systematic study of what settings contributed most to "explosion" of simulated fabrics. Because there were too many complexities in off-the-shelf models, I created my own which included just one potential trouble spot -- a plane with an added toroid which introduced a non-planar topology. (See attachment 1.) As more or less expected, it exploded when I tried to drape it over a genesis figure. To my surprise, however, the problems didn't end up being primarily due to self-collision or the odd topology. I was able to eliminate the problem with various combinations of setting changes:

1. Simply setting the "bend stiffness" to .25 instead of .5 was, in itself, sufficient to fix the problem. (See attachment 2. The simulation is plausible, but the "donut" section completely collapses, as the fabric lacks stiffness.)
2. Setting "buckling stiffness" to its minimum was enough to almost fix the problem. (It didn't blow up until the last moment.) Adding in decreases to either stretch stiffness or shear stiffness was enough to make it behave properly.
3. Setting "dynamics strength" to 90 was enough to keep it from exploding, but also limited the amout of draping. Combinining this reduction with a figure that already has morphs might provide a good hybrid approach for some situations.
4. Finally I went back to zbrush and actually changed the geometry of the model.Retopologizing so that it had only quads instead of a mix of quads and triangles seemed to be all that was needed. The model simulated smoothly and easily. (See attachment 3. The draping is more interesting and the shape of the donut doesn't get completely lost.)
5. "Decimated" versions (triangle-based) of the original model exploded in the same way as the original. Decimated versions of the retopologized version didn't explode, though the simulation wasn't as pretty, due to reduced polygon count.

Summary:

1. Clean topology matters. It's probably necessary to have non-intersecting "watertight" meshes, but it's not sufficient.
2. If you have no control over the topology, try simply tweaking the bend stiffness. That may be all you need to change.

 

BeeMKay

Hi mephoria,

thank you so much for your experimentations, and even more so for sharing your results!

I finally able to properly drape a body suit that had been exploding on me for a good  while.  Now, I just need to figure out how to make the buttons play along...

 

Masterstroke

I just had an expected exploding simulation. The reason was a sitting pose. G8f's hip intersecting the armchair has been the reason for it. That's what I'd call a collision conflict. The dress has been stuck between the hip and the chair. Couldn't we have as a workaround a pop up warning, that let us make the decision, if e.g the dress should collide with the figure's hip or the underneath chair? So a having a collision hirachy in case of this kind of a conflict.  Is this possible to add in a later version of dforce?

SimonJM

Masterstroke said:

I just had an expected exploding simulation. The reason was a sitting pose. G8f's hip intersecting the armchair has been the reason for it. That's what I'd call a collision conflict. The dress has been stuck between the hip and the chair. Couldn't we have as a workaround a pop up warning, that let us make the decision, if e.g the dress should collide with the figure's hip or the underneath chair? So a having a collision hirachy in case of this kind of a conflict.  Is this possible to add in a later version of dforce?

Might the Layer option help out there?  It is something i have in my amorphous plans to look at, sometime!

Richard Haseltine

How would it know there was going to be a conflict until too late? You could always use a weight map or a material zone to exclude the problem area of the chair (which will presumably be hidden) while allowing collision on other areas.

mephoria

It kind of seems as if you are having problems because you are trying to run a physics simulation based upon a physically impossible start condition. The good news is that you can probably fix the situation pretty easily. Simply apply a smoothing modifier to the chair, and smooth it against your figure so that there is no collision. Bake in the smoothing morph and (optionally) raise your figure by some trivial amount (0.05 should be fine) so that there is some additional separation. Now simulate from stored pose, and your cloth will end up nicely sandwiched between the figure and the chair.

I tested this out with a cube for a chair and a plane for a piece of cloth, and it worked just fine. (The biggest problem was setting it up so that the "memorized pose" wasn't embedded in the chair. I worked around this by setting up a simple animation which started the figure above the "chair" and lowered it into position.)

(Note that in the attachment, only the plane was simulated. I also smoothed the plane against the cube after running the simulation because the simulation wasn't quite smooth enough and created it's own intersection between the two surface. Still, the end result was something that's pretty physically accurate and doesn't blow up and, as a bonus, actually illustrates the effect of the figure sinking into the couch.)

 

melanie

I had the free Bardot dress that was given to us just before dForce released explode when I simulated it. I have another outfit for dForce that does not explode, so I thought maybe the Bardot dress possibly has a glitch in it.

s_j_gregory

I was not nearly as disciplined as some.  But I struggled for a couple of days ‘randomly’ attempting various settings to get even the Bardot Outfit included in the dForce starter to work.  In the end, I went back to a default G8F and increased the Offset Value parameter and set Self Collide to Off in order to stop it from exploding.  It worked

 

ZarconDeeGrissom

Thanks s_j_gregory_e8bd5afee1.  "Bardot Outfit included in the dForce starter" Thank you. I was trying to figure out where the thing came from. It was not listed anywhere, and it is giving me errors. Thanks, I have much to do, chat later.

(Missing file: data/mada/bardot/bardot skirt/uv sets/mada/base/default(dot)dsf), Same for the top mats.

Uninstalling it will be rather interesting I guess, lol.

D Ov

Hi all,

I have read carefully and tried to follow all the suggestions to avoid the pants from exploding to no avail. I tried applying pants presets unsuccessfully. I created a new file with only the G2 and the pants and then applied a simple animations, no luck. I can't think of what I am doing wrong. I even removed the chair the figure is sitting on. I then exported the pantsa as an obj and imported it. Same thing. I am using Business Class Two pants (https://www.daz3d.com/business-class-two) on G2F. Such a pain! Here's a screenshot. Any thoughts?

Richard Haseltine

It may be that those simply won't simulate - soem items are not made in a way that, in retrospect, is dForce friendly.

D Ov

Meanwhile I have tried the pants MADE for DForce. Same thing. So, I got another pair form another vendor and appled Dynamic Clothing instead.

Platnumk

Set the Bend Stiffness to 0.05 and then do a simulation,  If all goes well then increase the Bend Stiffness by 0.05 and simulate again, Repeat this until you hit the point where the material explodes,  Once the material explodes then reduce the Bend Stiffness by either 0.01 or 0.02 and simulate, repeat untl the material no longer explodes.

All thats left to do is save the simulation settings for later use so that you don't have to go through all again for that piece of clothing.

nicstt

I've noticed that if there are orphan or stray vertices, which I usually notice after exporting to morph, this seems to be one possible reason for explosions.

Aave Nainen

D Ov said:

Hi all,

I have read carefully and tried to follow all the suggestions to avoid the pants from exploding to no avail. I tried applying pants presets unsuccessfully. I created a new file with only the G2 and the pants and then applied a simple animations, no luck. I can't think of what I am doing wrong. I even removed the chair the figure is sitting on. I then exported the pantsa as an obj and imported it. Same thing. I am using Business Class Two pants (https://www.daz3d.com/business-class-two) on G2F. Such a pain! Here's a screenshot. Any thoughts?

I've just done a test run simulating Business Class Two on G2F, with a simple (animated simulation) to sitting pose on a cube with a ground plane.  Setting Bend Stiffness to .30, reduce simulation strength on the waistband to .50, adjusted ground plane on Y axis at "0" to a negative value to keep figure from going through the ground plane and brought plane back up to "0" on the Y axis at frame 30. The cube she's sitting on also needs to be set at a negative value on Z  axis to bring it behind the figure at starting frame and set at desired position for final frame.

 

D Ov

Wow! Thanks AAVE! I will try those settings immediately

 

D Ov

not sure about this part "reduce simulation strength on the waistband to .50". There's Stretch Stiffness, Shear Stiffness etc but not seeing simulation strength

 

Richard Haseltine

D Ov said:

not sure about this part "reduce simulation strength on the waistband to .50". There's Stretch Stiffness, Shear Stiffness etc but not seeing simulation strength

Dynamic Strength, perhaps.

D Ov

Noppe, no go. I didn't set any planes or cubes to avoid any collision. It explodes a few frames in.

D Ov

Perhaps I shouldn't use the Transfer Utility tool but just assign the pants to the figure instead...

D Ov

Tried turning off Self-Collide option. Same things, explodes on frame 3 or 4

Aave Nainen

I see you are using an animation sequence in which case you would need to go through the animation frame by frame to correct any collision points. My test was based on going from default pose to a seated pose at frame 25 leaving last 5 frames for garment to settle.  If it is the figures hands colliding you can try selecting the hands (along with children of the hands) and turning "Visible in Simulation" to Off for just those parts of the figure. Legs crossing are also a frequent culprit so you would need to get creative in adjusting along timeline so that legs don't cross at points that will cause collision with the garment.  Might be helpful if you could post a video capture of the animation sequence you are trying to use.

D Ov

Thank you Aave. Yes, I realised the legs and arms have been causing issues. I tried different pants found out the same. Let me "get creative" and see if I can avoid collisions. Does that mean I cannot have a figure sitting with the legs crossed?

Aave Nainen

Not at all, you just need to arrange the simulation so that the legs don't cross at the wrong point in time.  It can be a bit tricky but if you start by scrubbing the timeline to the point where legs start to intersect and bend one offending leg out and away so that it crosses further down the timeline it can be done.

D Ov

Thank you Aave. I keep on trying with a limited success though. Got myself yet another item to try mu luck with it.

D Ov

Ok, my overall conclusion about this whole DForce business - it's not plug and play. It will not work unless you deal with a DForce taylored items. Or unless you want to spend hours on changing geometry, weight maps etc.. i.e basically remodeling the item.Or if you want the figure to stay still. Forget about "Dynamic Surface". After the clothing explodes it also screws up my RAM and the PC runs a ttturtle speed. Like now, I need to reboot to get back to normal. Just fyi, here are the specs for my PC: Intel i7-7700K CPU 4.20 GHz, 16.GB RAM, 64-bit, Win 7. Not enought for DAZ Studio, huh? I have a long list of complains about DS as animation tool, but I just love their characters and props, some aniblockss and the ease of posing. I don't have another 5 years to learn Maya. Iclone is notn early as detailed and elaborate in terms of creating characters but it certainly has the advantage of fast rendering.  Enougt for now, rebooting my PC after trying work with this DForce. duh...