problems with hair system in combination with dynamic constraints

[thefreshestever]

hi at all...

 

i have a model with hair, the model also has some dynamic constraints. when i´m rendering with the hair turned off, the dynamic constraints work fine, but when i render with hair on, no dynamic constraint movement shows in the render. the hair dynamics work fine, just that the hair seems to prevent the dynamic constraints to work. any clue?

 

i have another little problem with this model, maybe some rigging experts can help...

the model was rigged with the squetch rig, everything is working as it should, except one thing:

the ring finger curl isn´t working, all other fingers are fine though... i noticed that in the "relationships>bones" folder are smart-skins for the fingers curls, only the ones for the ring fingers are missing... i tried to fix it, but i can´t get it to work right, because i don´t really know what these smartsins do... i would go back to a previous version of the model and rig it again usually, but i just got aware of this issue after completely weighting the model, and believe me, i don´t wanna do this again

 

thanks in advance...

[itsjustme]

i have another little problem with this model, maybe some rigging experts can help...

the model was rigged with the squetch rig, everything is working as it should, except one thing:

the ring finger curl isn´t working, all other fingers are fine though... i noticed that in the "relationships>bones" folder are smart-skins for the fingers curls, only the ones for the ring fingers are missing... i tried to fix it, but i can´t get it to work right, because i don´t really know what these smartsins do... i would go back to a previous version of the model and rig it again usually, but i just got aware of this issue after completely weighting the model, and believe me, i don´t wanna do this again

 

thanks in advance...

 

I sent you an e-mail, Sebastian...I think the address is current. If you have my e-mail address, you can shoot the model at me if you'd like.

[thefreshestever]

i have another little problem with this model, maybe some rigging experts can help...

the model was rigged with the squetch rig, everything is working as it should, except one thing:

the ring finger curl isn´t working, all other fingers are fine though... i noticed that in the "relationships>bones" folder are smart-skins for the fingers curls, only the ones for the ring fingers are missing... i tried to fix it, but i can´t get it to work right, because i don´t really know what these smartsins do... i would go back to a previous version of the model and rig it again usually, but i just got aware of this issue after completely weighting the model, and believe me, i don´t wanna do this again

 

thanks in advance...

 

I sent you an e-mail, Sebastian...I think the address is current. If you have my e-mail address, you can shoot the model at me if you'd like.

thanks david, i really appreciate your help

[NancyGormezano]

hi at all...

 

i have a model with hair, the model also has some dynamic constraints. when i´m rendering with the hair turned off, the dynamic constraints work fine, but when i render with hair on, no dynamic constraint movement shows in the render. the hair dynamics work fine, just that the hair seems to prevent the dynamic constraints to work. any clue?

 

I don't know what version you are using, but in previous versions there was a problem, just as you describe. However in later versions, one can right click in chor and "simulate springs - or something like that " (with hair off) first, and the dynamic bones will get "baked". Ie channels will appear. Then turn hair back on and render.

 

Also sometimes dynamic bone movement will look different in real time then after it gets simulated/baked.

[thefreshestever]

hi at all...

 

i have a model with hair, the model also has some dynamic constraints. when i´m rendering with the hair turned off, the dynamic constraints work fine, but when i render with hair on, no dynamic constraint movement shows in the render. the hair dynamics work fine, just that the hair seems to prevent the dynamic constraints to work. any clue?

 

I don't know what version you are using, but in previous versions there was a problem, just as you describe. However in later versions, one can right click in chor and "simulate springs - or something like that " (with hair off) first, and the dynamic bones will get "baked". Ie channels will appear. Then turn hair back on and render.

 

Also sometimes dynamic bone movement will look different in real time then after it gets simulated/baked.

thanks nancy....

unfortunately this doesn´t do the trick...

now it´s just the other way round: dynamic constraints render properly, but the hair just stays completely in place. i´m using v15j on a mac... same problem with v16beta...

[NancyGormezano]

hi at all...

 

i have a model with hair, the model also has some dynamic constraints. when i´m rendering with the hair turned off, the dynamic constraints work fine, but when i render with hair on, no dynamic constraint movement shows in the render. the hair dynamics work fine, just that the hair seems to prevent the dynamic constraints to work. any clue?

 

I don't know what version you are using, but in previous versions there was a problem, just as you describe. However in later versions, one can right click in chor and "simulate springs - or something like that " (with hair off) first, and the dynamic bones will get "baked". Ie channels will appear. Then turn hair back on and render.

 

Also sometimes dynamic bone movement will look different in real time then after it gets simulated/baked.

thanks nancy....

unfortunately this doesn´t do the trick...

now it´s just the other way round: dynamic constraints render properly, but the hair just stays completely in place. i´m using v15j on a mac... same problem with v16beta...

 

After simulating springs, you can also "bake hair" - separate file(s) are then created for the hair system(s) dynamics. The file names will show in the chor... this would work in 15e (PC) ... I am not sure about later versions, nor the Mac.

 

Not sure how it is determined where the hair file(s) are created. I believe they show in the same directory as the project file. Unfortunately that means you have to make a project. Which I don't, I only like to work with chors, because I don't like how saving a project will save everything that has changed. I prefer to save things individually. I wish there was a way to set the destination for the hair file. (probably could change it in a text editor)

[thefreshestever]

hi at all...

 

i have a model with hair, the model also has some dynamic constraints. when i´m rendering with the hair turned off, the dynamic constraints work fine, but when i render with hair on, no dynamic constraint movement shows in the render. the hair dynamics work fine, just that the hair seems to prevent the dynamic constraints to work. any clue?

 

I don't know what version you are using, but in previous versions there was a problem, just as you describe. However in later versions, one can right click in chor and "simulate springs - or something like that " (with hair off) first, and the dynamic bones will get "baked". Ie channels will appear. Then turn hair back on and render.

 

Also sometimes dynamic bone movement will look different in real time then after it gets simulated/baked.

thanks nancy....

unfortunately this doesn´t do the trick...

now it´s just the other way round: dynamic constraints render properly, but the hair just stays completely in place. i´m using v15j on a mac... same problem with v16beta...

 

After simulating springs, you can also "bake hair" - separate file(s) are then created for the hair system(s) dynamics. The file names will show in the chor... this would work in 15e (PC) ... I am not sure about later versions, nor the Mac.

 

Not sure how it is determined where the hair file(s) are created. I believe they show in the same directory as the project file. Unfortunately that means you have to make a project. Which I don't, I only like to work with chors, because I don't like how saving a project will save everything that has changed. I prefer to save things individually. I wish there was a way to set the destination for the hair file. (probably could change it in a text editor)

hmm... tried that, there´s nothing showing up in the chor or prj... just some .pai and .par files are created in the same directory as the prj-file, like you said... but i don´t know what to do with them... anyway, i think i will give the hair a different approach, i´m not completely happy with the behaviour (can´t avoid the hair going through the shoulders sometimes) of the hair system... after robs amazing tests with cloth i think i will give simcloth a try to do the hair... seems to be much more accurate in collision detection...

[NancyGormezano]

hmm... tried that, there´s nothing showing up in the chor or prj... just some .pai and .par files are created in the same directory as the prj-file, like you said... but i don´t know what to do with them... anyway, i think i will give the hair a different approach, i´m not completely happy with the behaviour (can´t avoid the hair going through the shoulders sometimes) of the hair system... after robs amazing tests with cloth i think i will give simcloth a try to do the hair... seems to be much more accurate in collision detection...

 

You don't do anything with the hair files - that is where the dynamic data is saved for the hair. You can now play in real-time with hair on, and you should see how it will render, behave. If you change any of your animation for the model, you would have to "bake hair" again of course. If you don't - it would stay in the same place as before.

 

As for collision detection of hair, John Bigboote, I believe found that many cp's for hair (7?) has better CD and I also believe he has "invisible deflectors" on his models around the shoulders. I personally don't use the CD system for hair, so I can't say anything about it. But his tests look pretty good - I will try to hunt up link.

 

Cloth is another option. I haven't tried that either for hair.

[NancyGormezano]

HERE is Matt/John's thread on Hair & Collision Detection

[detbear]

Hey There... Hair with Dynamics seems to be a very delicate partnership. I had problems with this in V.15 and several lower versions... 1.Sometimes it was merely a re-boot of the choreography that fixed...BUT CONSIDER THIS:

 

Are you starting the render/ shot at frame 000, OR are you beginning the render at a further frame in the sequnce. For instance...Does your animation/ sequence have 500 frames and you are only rendering 220-350(just an example) Sometimes when you start the render at a frame later in the sequence, the dynamic calculations mess up in trying to solve where the "Hair" should be at that frame.. I've had cases where I had to completely cut frames out and bring shots back to start at frame 000 in order to get the dynamics and hair to work correctly.

 

If the sequence and/ or movement of your model/ shot begins much earlier than the frames you are trying to render, this will sometimes cause problems.

 

William

[HomeSlice]

rendering 220-350(just an example) Sometimes when you start the render at a frame later in the sequence, the dynamic calculations mess up in trying to solve where the "Hair" should be at that frame.

When you animation is done, and before you start your final test preview renders, try "Baking Particle Systems" in the chor. See if that helps.

[thefreshestever]

i can´t get hair to render AND the dynamic constraints, no matter what i do. so i made some kind of "hair-helmet" with cloth-simulation... sinke this is a cartoony character anyway, i´m pretty happy with the look so far. the simulation works fine, if i don´t have too much fast movement...

 

in previous simcloth versions there was a setting for the collision-detection distance, i can´t find anything like that, so i´ve build a deflector slightly inside the body, because the deflection-range seems pretty high, about 2-3 cm or so... or did i just not find the setting???

 

also if the cloth is deflected, there´s always some kind of weird jittering, so the hair looks sometimes more like a fidgeting fish than hair...

 

any advice?

[NancyGormezano]

i can´t get hair to render AND the dynamic constraints, no matter what i do.

 

Hmmm, bummer....sorry, I can't help you with the cloth. I did notice also there is a weird distance thing going on for collision distance & cloth.

 

However, I just tried dynamic constraints, hair and collision detection in 16beta5/32. It worked beautifully (first time I've really tried collision detection). So something is going on in particular with your chor/project.

 

what I did:

 

1) made sure my chor range was set properly

2) turned hair off

3) baked dynamic systems (channels would show up for the bones involved)

4) turned hair on

5) baked particle systems (files would be created in project folder), groups would show up in chor pointing to these files

6) rendered multipass

 

when I found I wanted to experiment with the hair settings, after rendering - I did NOT unbake particles first - but just ran "bake particle system" again and it worked wonderfully. In the past I believe there would be some funny business with unbaking and baking. No jittering either.

 

I am so impressed with ver16. Great job Steffen!

[thefreshestever]

hmmm.... exactly what i did... 1st problem is that after baking the particles, the movement of the dynamic constraints is gone. the channels still exist, but there´s no keyframes in it anymore. 2nd problem is that the hair systems mess up sometimes in a weird way: the end of the hair just stays exactly in place, while the beginning of the hair follows the models geometry. so short hair just straighten out...

 

maybe a mac-bug?

 

i might give it another try sometimes with a very simple, new model with new hairsystems from scratch, maybe i can figure out what went wrong.

[NancyGormezano]

hmmm.... exactly what i did... 1st problem is that after baking the particles, the movement of the dynamic constraints is gone. the channels still exist, but there´s no keyframes in it anymore. 2nd problem is that the hair systems mess up sometimes in a weird way: the end of the hair just stays exactly in place, while the beginning of the hair follows the models geometry. so short hair just straighten out...

 

maybe a mac-bug?

 

i might give it another try sometimes with a very simple, new model with new hairsystems from scratch, maybe i can figure out what went wrong.

 

Yes, Could be mac specific, or maybe your settings for constraints both in hair and dynamic? I'm doing very vanilla settings.

 

In my test - the black whiskas are dynamic (set in a pose, default settings) & the hair is constraint type, 30% stiff, use gravity OFF, 20% drag, CD ON with default settings.

 

However, I thought that when I set the dynamic constraints in a pose - I changed some of the settings for the whiskas - and I'm thinking they didn't stick? I will investigate that further.

 

EDIT: I also don't have collision detection on for the dynamic constraints. Only for the hair. Just tested changing settings for Dynamic in pose and seems to work.

testhairdynamiccollisionfogfaketailh264loop.mov

Edited December 18, 2010 by NancyGormezano

[thefreshestever]

haha, that lion looks great. some sort of pug-lion with that much left-over skin..

 

the dynamics look great, i´ll let you know if i ever get it to work.

[HomeSlice]

1st problem is that after baking the particles, the movement of the dynamic constraints is gone. the channels still exist, but there´s no keyframes in it anymore.

I had this problem in v15J+ on PC. I also saw it once in v16 beta, but when I tried to make a simple test project for a bug report, it worked without any problems <_ so i could not make the bug report.>

 

If it happens to you, select a bone in the chor and look at the channels. Do you see a bunch of channels named "Transform.Dynamic Results ?

If you do, then you can fix the freezing dynamics issue.

Make sure you are on frame 0.

Turn your Dynamics Pose OFF or turn the Dynamic Constraint off. This should create normal X,Y,Z rotation channels in the chor action if they don't already exist.

Select all the keyframes in the Transform.Dynamic Results.X channel. Just drag your mouse around them to select them all at once. You can also do it in the Curves editor if needed.

Select the first keyframe in the Transform.Rotate.X channel and Paste. All the keyframes you copied should paste into this channel.

Repeat these steps for the Y and Z channels.

[thefreshestever]

thanks holmes...

 

i finally got it t!!! after fiddling around for hours with the cloth-hair without getting any satisfying result i went back to particle-hair...

 

there was something wrong with the project or the chor... after saving the model without hair and doing the hair from scratch everything did work fine... there was still an issue with the dynamic constraints (when baking dynamics in the chor, some dynamic constraints didn´t bake properly, there were keyframes missing somehow), but i was able to work my way around for now by baking the dynamics in the action and the particles in the chor... that won´t work for everything, let´s see if i can find a more satisfying solution...

[John Bigboote]

there was still an issue with the dynamic constraints (when baking dynamics in the chor, some dynamic constraints didn´t bake properly, there were keyframes missing somehow)

 

 

There is a setting you can fix for that... go to your choreography properties... twirl-down the dynamics triangle... and set the 'Reduction Error Tolerance' to zero (it's default is .01) this will allow the dynamic constraint to simulate properly and set a key frame on every frame.

[thefreshestever]

thanks matt...

i stumbled on this setting before and was wondering what it does... but why the heck is there a setting by default that produces errors???

[thefreshestever]

another weird thing i found out:

everytime i change my project framerate to 25 fps, the hair simulation messes up! started a new project with the default framerate of 30 fps, loaded my model, made a new chor. dragged my model into the chor, moved it from left to right. the hair simulation worked fine. then i closed the chor, changed the framerate to 25 fps, reopened the chor, and the hair simulation messed up, the tips of the hair just stayed in place. then i changed the fps to 24, everything worked fine again. would be interesting if anyone is getting the same result....