Why does it not work ?

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  • RoygeeRoygee Posts: 2,247
    edited December 1969

    As my contribution to science, I attach a matrix of the default settings for various cloth types in Blender, which work very well. See if you guys can translate to Carrara settings :) Settings in Blender are normally 1 =100%

    No point me trying in C8.1 because the headings have changed quite a lot in C8.5.

    What has been emphasized in Blender tuts is that damping is of utmost importance and IIRC, Joe has written that that setting is disabled in C8.5?

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  • JonstarkJonstark Posts: 2,738
    edited December 1969

    Thanks Roy, that looks like incredibly useful info! It might directly translate, but just seen the ratios between different settings can really help in zoning in on better cloth settings.

    Bookmarking your post :)

  • DiomedeDiomede Posts: 15,158
    edited December 1969

    Subject to Joe's excellent point about the density slider having no apparent effect, here are the settings under the effects tab in C8.5 physics for different materials from the drop-down menu.

    Effects tab hard body physics

    Density Bounce Friction
    cardboard 0.2 5% 50%
    clay 1.5 2% 85%
    ice 0.92 15% 2%
    metal 7.86 95% 30%
    plastic 1.1 70% 10%
    rubber 0.91 95% 85%
    wood 0.525 50% 20%

  • RoygeeRoygee Posts: 2,247
    edited December 1969

    All in the name of scientific exploration :)

    Those presets were from way before Bullett was introduced to Carrara - I find it incredible that after, what, 5 years, Daz has not included any presets that relate to cloth!

  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    Those presets were probably introduced with the standard physics engine and DAZ most likely had nothing to do with their introduction. since I believe it was Eovia that bough/licensed the old physics engine. Does Bullet even see those, or does Bullet have its own set surface parameters that are used?

  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited March 2015

    Roygee said:
    What has been emphasized in Blender tuts is that damping is of utmost importance and IIRC, Joe has written that that setting is disabled in C8.5?

    Yeah, Damping, in the simple mass-spring model I posted, is like modelling friction in parallel with all the springs. Without Damping, the springs (like real-world springs) just keep bouncing up and down.

    Damping is extremely important when modelling real cloth, but is disabled in Carrara's Bullet. Which probably means that, in the same way that Density is being modelled with a constant value, but the slider is inactive, there is a constant Damping being modelled, but there's no user input to vary that setting.

    Which means that cloth sims in Carrara all respond like they are rubber, constantly twitching and never really settling very well.

    Post edited by JoeMamma2000 on
  • MythmakerMythmaker Posts: 606
    edited March 2015

    @Marcus, iClone 6 has even better soft cloth implementation, so intuitive I made bouncy jelly hair in minutes with no 3dxchange5! But yes I totally relate to the passion of the quest, the joys and the frustrations. Have you tried the Cloth Deformer route? I'm onto it right now...

    My purpose here is not to be contentious, just want to show the OP - a new arrival from iClone to Carrara that the allegedly "disabled/ unconnected" Bullet Soft Body features in Carrara do work. At least in my 8.5pro Win7/64. So go ahead and experiment...with an opened mind... :)

    Good news is, even for non-CG-gurus like me, it is super easy to verify theories using SIMPLE YET SCIENTIFIC testing protocols

    Pic shows 4 different sim renders of the same dress with very energetic motion
    - My basic cloth settings, and the same cloth with
    - Air Drag 100
    - Air Lift 100
    - Volume 100

    Experienced dynamic cloth pursuers would note that the seemingly minor resulted variations would matter a great deal for collision.

    The point is not to show that Carrara Bullet soft body is ideal for clothing sim (my method is different but as tedious as existing methods), but to show what we thought were defunct actually work under the right conditions, and hopefully bring some faith to fellow passionate proactive testers.

    Cheers!

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    Post edited by Mythmaker on
  • TangoAlphaTangoAlpha Posts: 4,584
    edited December 1969

    I've managed to get a reasonable zero-wind flag drape, but the problem I have is that the bottom of the flag nearest the pole seems much too rigid and doesn't bend like the rest of the flag.

    The flag is just a 32x32 grid, with two attachment points. Changing the material setting doesn't affect this, neither do the Stiffness/Bending values under Springs. Any ideas?

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  • MythmakerMythmaker Posts: 606
    edited March 2015

    Tim_A said:
    I've managed to get a reasonable zero-wind flag drape, but the problem I have is that the bottom of the flag nearest the pole seems much too rigid and doesn't bend like the rest of the flag.

    The flag is just a 32x32 grid, with two attachment points. Changing the material setting doesn't affect this, neither do the Stiffness/Bending values under Springs. Any ideas?

    Only one major adjustment needed: the grid topology - trim it to 32 x 20-ish instead of scaling a 32x32 to a rectangle. Generally speaking for physics sims evenly-spread vertex density is preferred. Personally I would add 2 more vertices to each existing soft attach vertex for softer hang but that's optional.

    For rendering flags keep everything at DEFAULT. Default Scene physics, Effects/material, and default soft body settings. Turn self-collision on but still keep margin at default 100.

    That's it, nothing to it...

    Complexity only starts when the cloth needs to attach to another animated object and especially rigged figures. Otherwise it all works fine out of the box. Sometimes we got to trust the engineers.
    :D
    A 10 min job, with a Directional force added only at the end, also default speed. Enough to illustrate that the basic things are fine as they are, I hope.

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    Post edited by Mythmaker on
  • TangoAlphaTangoAlpha Posts: 4,584
    edited December 1969

    What version of Carrara? Cos mine (8.5) completely stuffs up if you use the default settings. And it doesn't fix my "stiff bottom" problem either.

  • DUDUDUDU Posts: 1,945
    edited December 1969

    Have you tried a rubber material for the flag ?
    Discrease the density of the material to try...

  • TangoAlphaTangoAlpha Posts: 4,584
    edited December 1969

    Yes, I've tried every material in the list. (Strangely, cardboard and wood seem to produce the best looking cloth drapes!)

  • Hermit CrabHermit Crab Posts: 841
    edited December 1969

    Thanks, Roygee, Diomede64, JoMamma2000 and Mythmaker for all the contributions to this discussion as we all- try to make sense of what DAZ has given us.

    @Evilproducer, In response to your question I've just tried a normal soft-body/attach simulation and then re-run it by changing the material to rubber, wood or metal (the ones I tried). It made no difference! Yet others here are finding differences...??

    @Tim_A, I can't figure out what is keeping that lower edge of the flag rigid. If you make some kinds of changes to the mesh (or close the scene and re-open??), you need to re-edit the soft-body attach. Different vertices will have been selected and you need to start over. It looks so much to me that one or more vertices along the bottom edge are selected despite what your screen-shot shows.

    Something that might explain why settings changes seem to make no difference is that such changes can take place along the timeline as keyframes if you weren't at frame zero when you made the changes. Re-play your simulation and watch the sliders to see if they are moving back to the values you changed.

    Sorry I can't help further. I made a flag and couldn't get such a flat edge as you are having. I did, however, play with directional forces and learned something new, if that's any consolation. (ducks to avoid being slapped on the head.)

  • Hermit CrabHermit Crab Posts: 841
    edited December 1969

    Hi Mythmaker,

    Yes, I have iclone6 but haven't used it much yet.

    The old physics of iclone5 worked really well and I found it easy to grasp but creating any kind of clothing was the preserve of a few individuals who had a particular version of 3dsMax and a particular Developer plugin from Reallusion.

    Those few could create items for sale with pinning features (our attach). Everyone else could make tablecloths that would fall onto a physics-enabled table or the ground and hopefully stay there or else fall off the bottom of the screen.

    Here is a very short video of something I did in the old iclone - the purpose of the video is to discuss the accompanying music but it shows some physics clothing I bought.

    https://www.youtube.com/watch?v=-iTFRIhnATU

    When I started trying out Carrara's physics, it was with 8.5 and I knew nothing of what had gone before (I'd never looked at it). The great news for me was that pinning/attach was built in but the bad news I found was that collision implementation was only partial compared to Iclone's.

    Carrara's soft-body can do excellent still drapes (subject to Joe's observation that 'springs' keep on springing) but when an object being draped changes position (is moving) the collision generally fails and the object passes through the soft body. (eg a character's leg passes through a long robe).

    As you will have seen in another thread, there have been attempts to get round this by cladding limbs with soft-body 'armour'. Soft-body collides against soft-body and it can be successful but no-one is yet offering basic, ready-to-wear, soft-body clothing that others can fit and use. (I think the day will come).

    I wasn't sure what you meant when you said you were into cloth deformations? You're referring to soft-body/soft-body attach?

    Your image shows great results but I'm not certain how it was done. There are four versions of the simulation results all on top of each other? If so they all look impressive.

    Was the image a frame from an animation? Or was it a still pose? If so, did you start from a T-pose?

    It looks good but I'm baffled by it and look forward to seeing more.

  • MythmakerMythmaker Posts: 606
    edited December 1969

    Hi again Marcus, sorry for not elaborating. I usually do. I only posted to keep this thread in a positive things-do-work direction, and to show that simple soft body sim calls for simple settings.

    Your inspiring cloth experiments are among the Carrara user videos that showed me it can be done. I sign up to Carrara for 3 things: dynamic cloth potential, dynamic fiber hair, Octane. So i'm determined to make it work.

    The 4-dress pic shows conformed dress mesh ANIMATED (tpose-energetic-motion-tpose) on Genesis then anim-baked then duplicate - with 3 settings (basic cloth + XYZ@100). Then playback. Goal is to show that

    1. allegedly disabled settings actually produce visible effect
    2. it is easy to set up your own protocol to test hypothesis, our own or others' (in fact it is the least convoluted path)

    I do plan to post a Dynamic Cloth Options in Carrara "overview" topic soon, to sum up my recent findings for new arrivals. So will respond in brief...

    I'm aware of the Bullet soft body/attach underarmor for V4 method you guys/gals are onto. Inspiring enthusiasm there. But I want to achieve 3 very specific things that have not been discussed much here: PARTIAL soft clothing on DS-AUTOFIT clothing on GENESIS. Some blind fumbling later I got some drastically different but still-convoluted methods. Not sure if the Poser/V4 scene will find them useful. But will post them too in the coming overview topic too...

    http://carraracafe.com/tag/cloth-deformer/
    http://www.sparrowhawke3d.com/blog/
    Cloth Deformer is a 3rd party Carrara cloth plugin by Sparrowhawke. I've just discovered it last week, played with it for a few hours. All I can say about it at this early point is it has MANY features I wish Carrara Bullet soft body had. Wish I found it earlier! It was also designed to work with Genesis and autofit clothing! Has GRADIENT MAPPING too! MULTIPLE weight types! Slower sim, but overall faster workflow - SO FAR. A really really happy find. Surprise that it is not getting the attention it deserves. Check it out!

  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited December 1969

    Mythmaker said:
    The 4-dress pic shows conformed dress mesh ANIMATED (tpose-energetic-motion-tpose) on Genesis then anim-baked then duplicate - with 3 settings (basic cloth + XYZ@100). Then playback. Goal is to show that

    1. allegedly disabled settings actually produce visible effect
    2. it is easy to set up your own protocol to test hypothesis, our own or others' (in fact it is the least convoluted path)

    Mythmaker,
    I'm not trying to be contentious, just trying to understand what point you're making. Apparently you are saying that some of the settings that I and others believe to be disconnected are actually connected? And you are showing an image of 4 dresses draped on a character to prove it?

    Maybe my brain is too small to comprehend it, and if so I apologize. But if a setting slider is connected there should be a very clear and simple way to prove it.

    When I say Density is disconnected, it's because I hang a simple cloth object from its softbody attach points in mid-air, and it falls and bounces. I then vary the Density from 0 to maximum, which simulates the relative weight of the cloth, but the stretch of the cloth is absolutely unchanging as you vary Density. If you increase cloth density it should stretch more under gravity. That's how density works.

    Am I missing something, or are you talking about something else?

  • MythmakerMythmaker Posts: 606
    edited December 1969

    Tim_A said:
    What version of Carrara? Cos mine (8.5) completely stuffs up if you use the default settings. And it doesn't fix my "stiff bottom" problem either.

    8.5pro release version.

    Your stiff bottom is mainly caused by

    1. squeezing a 32x32 square grid into a 32x16 shape, causing uneven vertices distribution. The lower pinned vertex and its neighbors cannot move and get jammed into inertia unless you free their movement - by evening the grids out to little squares again.

    2. Stiffness set too high, default is fine, elaborated in last post.

    3. Advanced Quality set too high, default is fine, elaborated also...

    Cheers

  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited March 2015

    Tim_A,
    I tried to duplicate exactly your scene, with the settings shown in the attached image. A 32x32 flag, with those settings.

    And the result I get is a flag that is EXTREMELY stretchy. Not something you'd want as a flag, In fact I don't see the stiff results you see in your sim.

    My only guess is that I noticed you have many objects comprising your flag, and I have no clue what they are or how they're set. Maybe your cloth flag is colliding with them and causing apparent stiffness?

    And I've included an image from mid-sim to show how stretchy it is...

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  • MythmakerMythmaker Posts: 606
    edited March 2015

    Mythmaker said:
    The 4-dress pic shows conformed dress mesh ANIMATED (tpose-energetic-motion-tpose) on Genesis then anim-baked then duplicate - with 3 settings (basic cloth + XYZ@100). Then playback. Goal is to show that

    1. allegedly disabled settings actually produce visible effect
    2. it is easy to set up your own protocol to test hypothesis, our own or others' (in fact it is the least convoluted path)

    But if a setting slider is connected there should be a very clear and simple way to prove it.

    Indeed. And I created a simple protocol, tested it, and did prove it. I have laid it out too... It's easy and fast to set up. Try it...


    When I say Density is disconnected, it's because I hang a simple cloth object from its softbody attach points in mid-air, and it falls and bounces. I then vary the Density from 0 to maximum, which simulates the relative weight of the cloth, but the stretch of the cloth is absolutely unchanging as you vary Density. If you increase cloth density it should stretch more under gravity. That's how density works.

    Sounds to me like you have proven "that's not how Density works in Carrara", perhaps?

    Or, you have proven "Carrara Density did not work with Bullet soft body as I expect it to?"

    Or, you have proven "Carrara Density failed to behave like ABC app's Bullet Density?"

    Also, it is not clear what your other settings are. All are inter-related, as you say, so I try to not get into pointless "debates about isolates"...

    In any case, I don't see any proof of "Carrara Physics Density is DISCONNECTED from Carrara Bullet Soft Body Sim". In fact I found the opposite - I have gotten consistent result from tests - in Carrara's Bullet soft body sim, Density matters a great deal to collision.

    Why it is, how to refine/ exploit it, the inter-relations etc, too involved for this topic on flag sim. I will elaborate in my coming Carrara dynamic cloth overview post, promise...

    Post edited by Mythmaker on
  • JoeMamma2000JoeMamma2000 Posts: 2,615
    edited March 2015

    Mythmaker, I would attempt to duplicate your results if I could figure out what steps you made to get those results. But I can't. You have 4 dresses and somehow that proves something.

    Density is weight per unit volume. That's what it says in the dictionary (or at least something like that). The more density, the greater the weight, and the heavier the fabric, hence the greater stretch under constant gravity. That's a fact. If Carrara's Bullet is NOT configured that way, then it is effectively disabled, or it's not Density. But I very much doubt that, because they used the Bullet code that others developed. And it's correct.

    It seems very clear that what Carrara's Bullet has is a constant Density for all objects, and moving the slider does nothing.

    Anyway, I'm trying to learn my lesson about not chasing rabbits down a rabbit hole, so I'll stop here.

    Post edited by JoeMamma2000 on
  • MythmakerMythmaker Posts: 606
    edited March 2015

    JoeMamma2000, for my own sanity I try not to expect some arbitrary CG physics algorithms to behave like dictionary physics. But yes I agree it'll be nice if CG smoke simulation rules coincide with making real smoke. Maybe in 2030...?

    And sorry I can't fetch you detailed step-by-step here and now..as I said, discussion on advanced cloth topic too involved. This OP "why does flag sim not work?" is derailed enough...partly my fault...

    ------back on topic-----

    Summarizing my points about simulating simple flags...

    To get a flag that looks like fabric (and won't explode or spike) in under 30 minutes:

    - keep the topology EVEN (square shape polygons throughout)
    - keep top level physics settings - Scene physics, Effects: material, Spring etc AT DEFAULT
    - keep it simple

    Did I say, keep it simple? :)

    Further refinement:

    Recommendation (as in, not a rule): start with lowering Bending to 10%, and turn on self-collision. Nothing else. Will fetch good-enough 32x16 flag for me that won't penetrate itself, that will flow and fold nicely upon itself, collides well with the pole, and responds well to wind.

    Further marking around:

    keep it stupid - start with THE SIMPLEST DUMBEST POSSIBLE SETTINGS. Better to start with a so-so fabric that don't penetrate itself based on DEFAULT settings and tweak from there.

    keep it lean - design own strict protocols to test hypothesis. Best way to chase oneself through endless rabbit holes is to test new hypothesis on a foundation of untested hypothesis.

    That's it... happy getting things to work, with CLARITY.

    And...did I say, simplicity?

    Post edited by Mythmaker on
  • RoygeeRoygee Posts: 2,247
    edited December 1969

    ...and on a lighter note...my first animation made using the (then) brand-new soft-body cloth sim . June 19 2010 - not a lot seems to have changed since then :)

    https://www.youtube.com/watch?v=s-vYaJnueJ0

  • Hermit CrabHermit Crab Posts: 841
    edited December 1969

    I love the animation,Roygee. I remember seeing (a good while ago) an animation in Carrara of 'George of the Jungle'. It was fun too: 'Watch out for that treeeeeee...' I don't know whose it was.

    @Mythmaker. Following your links I now understand what you mean by Cloth Deformations. It is indeed something to be delighted with.

    I have to admit that, away back when I was first stumbling about exploring Carrara Physics, Evilproducer told me about Sparrowhawke's plugin and I took a look without installing it.

    Only now, with a better knowledge of the issues involved, am I in a position to appreciate the amazing work he has put into his plugin and to see how it has features that the native physics lacks.

    I tried various ways to create a 'hybrid' garment where the upper half would be bone animated and the lower physics enabled but it seems that one animation method refuses to live with another in the same object.

    Yet Sparrowhawke shows how to create conforming areas with Physics areas in the same piece. I'm looking forward to seeing the thread you are planning to start.

    Sparrowhawke's blog posts on conforming hair are also extremely interesting.

    I (tactfully) wonder whether installing the plugin makes a difference to the workability of other physics sliders in Carrara? One reason I didn't try out the plugin before was that I wasn't familiar enough with Carrara to change what I got as standard.

    Lastly, longer serving forum members may know much more about Sparrowhawke's work and whether he frequented this place much. It seems a great shame that he isn't here in the forefront of some of these discussions.

  • evilproducerevilproducer Posts: 9,050
    edited December 1969

    I love the animation,Roygee. I remember seeing (a good while ago) an animation in Carrara of 'George of the Jungle'. It was fun too: 'Watch out for that treeeeeee...' I don't know whose it was.

    @Mythmaker. Following your links I now understand what you mean by Cloth Deformations. It is indeed something to be delighted with.

    I have to admit that, away back when I was first stumbling about exploring Carrara Physics, Evilproducer told me about Sparrowhawke's plugin and I took a look without installing it.

    Only now, with a better knowledge of the issues involved, am I in a position to appreciate the amazing work he has put into his plugin and to see how it has features that the native physics lacks.

    I tried various ways to create a 'hybrid' garment where the upper half would be bone animated and the lower physics enabled but it seems that one animation method refuses to live with another in the same object.

    Yet Sparrowhawke shows how to create conforming areas with Physics areas in the same piece. I'm looking forward to seeing the thread you are planning to start.

    Sparrowhawke's blog posts on conforming hair are also extremely interesting.

    I (tactfully) wonder whether installing the plugin makes a difference to the workability of other physics sliders in Carrara? One reason I didn't try out the plugin before was that I wasn't familiar enough with Carrara to change what I got as standard.

    Lastly, longer serving forum members may know much more about Sparrowhawke's work and whether he frequented this place much. It seems a great shame that he isn't here in the forefront of some of these discussions.

    He used to post quite frequently, and still does from time to time. I suspect he has real world obligations that keep him busy.

  • Hermit CrabHermit Crab Posts: 841
    edited December 1969

    Thanks for the quick reply, Evilproducer.

    At least when I failed to explore the plugin you pointed out to me, the forum was spared lots of loooong posts and yawns!:-)

    To the OP - sorry about the thread wandering from topic of your question.

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