dForce, wind nodes, and Bang Bob Hair in an animation
wsgentry
Posts: 572
I'm trying to animate a figure walking on a sidewalk in a city. The figure uses Bang Bob Hair (it's dForce enabled). Along the characters path, I have set three dForce wind nodes with various dimensions and wind speeds. The path the character takes intersects with the falloff areas of each wind node. The effect I'm after is to have the hair react to the wind in a random fashion--based on position and wind speed, but not wildly. The manual only addresses wind nodes in single images.
What I don't understand, and the results are bearing this out, is this: Nothing. The hair does not blow at all. Single frame, no problem. I set up the animation to have 320 frames then simulate (simulation is set properly for an animation). When I render and playback, no movement of the hair. So, I'm thinking either I'm missing something really basic or this isn't possible?
Any ideas?
Thanks in advance,
Scott
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Comments
Wondering if the wind node requires a minimum number of frames.
Try parenting the wind node to the figure and rotating it away from the hair until it's needed. Or greatly increase the force?
The hair has an "Animate" script that sets up sixty frames. The rest of the settings are pretty much standard. I change the last frame to 320 and the timeline updates, so I'm pretty certain there's no limit except graphics card memory--which I have hit several times (1080ti).
Regarding wind speed (I'm thinking that's what you mean), the manual says the hair acts like it's being blown gently, which is what I'm after, however in other tests, with head-on wind and high windspeed (60mph, limits off), the bangs get blown back and the hair parts very unnaturally, almost like it was ripped off.
So, I've upped windspeed to over 50mph on all three wind nodes--different speeds to see what happens and it's rendering, now. It takes about seven hours to simulate then render this so I'm going to crash and see what happens when I get up. :) Oh, yes! I have done smaller animations--100 frames or so just to test, not long enough to completely stabilize the simulation.
Thanks!
Scott
No go. Trying again after repositioning the wind nodes.
Scott
No go on repositioning. I'm trying parenting again, but differently. I'm changing wind speeds radically at various points. Interesting stuff.
Scott
I've found the wind node to be a bit finicky anyway. I did get it to blow the Morphing Flame prop (after dForcing it) but IIRC the actual wind node fan had to be very close to it, not just the fire being in the tube.
I've noticed that the "wind" of dForce is a solid stream. You would need to create multiple frames with differing levels of wind to create the illusion of turbulance to get the effect that you are looking for. I used it to keep the bangs of her eyes for a close up shot and that was it.
The parented wind node is REALLY close to the figure with the output pointed directly at the hair. I'm 170 frames in right now and all I see so far is the bangs parting. :)
Scott
This is what I'm doing, now. Did you find the windspeed needed to be way, way high?
Scott
I'm beginning to think it's the hair. I tried the parented node with various windspeeds over 20 frames and the hair just stays put. I'm trying it with a different orientation for the wind node. Fun stuff, but time consuming.
One thing I did notice is between marks on the timeline, windspeed will either increase or decrease linearly between marks--it's a gradual incline or decline. So... I used zero between marks and windspeed goes negative. Interesting stuff. There's an old joke in there, but in this case, it's true.
Scott
It was a nice exercise, but I'm giving up for the time being. After I changed the length of the hair, Daz started getting "Simulation Error" alerts. Oh, well. :) I know how to do it for a single frame, but not in an animation.
Scott
yes, very high and very careful with the placements so that things would go and do what I wanted
Thanks! I'm going to get back to this later today. I think part of the problem is what I did with the hair. I turned off limits so I could make the hair longer. In a static image, I can get the hair to move, but this animation is really, really different. In an attempt to get the hair to move naturally while being animated, I turned off limits on the single wind node I parented, and shot wind at various velocities kind of like this:
0, 50, 20, 60, 0, 70,0 50, 0,30, 70,0
I put varying framing gaps between the values above ranging from 3 to 7 frames. What I found out is interesting. Air animates, too. By that I mean in the frame gap between 0 and 50, it would increase linearly until it reached 50 at the designated frame. In the frame gap between 50 and 20, the velocity would decrease in the same fashion. Because limits were off with regard to velocities (windspeed), the behavior of the final zero was interesting, too. In the frames after the zero, the velocity would go negative. So, 0 would end up at -8 mph or so after a few frames. I didn't expect that.
Frame-by-Frame examination of the images indicated some movement, but not a lot and once the hair moved, it pretty much stayed in the same place regardless of velocity at that frame. That's probably because of the velocity slope in the gaps between set velocities. So, now I'm wondering if there is a setting to turn off animating windspeed? If not, the same thing can be accomplished by aiming the wind node to not contact the character--it's just that re-aiming the wind node to the character is not going to be sudden because of frame gaps and animation. An interesting thing, I think. Two, or more wind nodes can take of that, though.
Another interesting thing is the actual aiming of the wind node--it changes as the character moves, even though the wind node was parented to the character. I found this out by using a top view and clicking through the animation. So, I re-aimed the wind node to fix that. I did not create the wind node with persistence, though. I'm wondering if that would eliminate the need for re-aiming? Interesting stuff.
It's very time consuming. For testing, to ensure accuracy, I'm animating anywhere from 80 to 100 frames. Even with a 1080ti, simulation and rendering takes a while--about two hours before I know if something works.
Scott
PS As an aside, it might be possible to simulate a tornado or its effects on objects in a scene... turn off limits, position wind nodes to create a swirling effect then have a wind node with a very high negative velocity in the center of the swirl and see how it reacts. Just musing. :)
Well, I finally got the hair to move! :) Not the way I want, yet. It turns out the longer hair probably has friction with the body and won't move--I'll look into parameters for that, so for the time being shorter hair is easier to get to move.
Scott
I can't imagine a tornado being possible at this time the way the wind force is written.
Maybe not. Just thowing it out there. My thought depends on whether or not dForce wind is capable of generating vortices after collisons with objects and whether an object in the center wind node can be lifted and influenced by the spin of a vortex. I believe you're right, though. It would take a lot to effectively "wind trace" or at best implement low-level CFD.
Oh, and wind didn't work. I was tired and missed the start frame of the animation. The movement I saw was because of walking, not because of wind. I'm done with it, for now. :) I'll get back to it. I need to check the static stuff I've done to make sure I've got the wind node positioned correctly. Imagine that! All this and it's me? Na... can't happen, right?
Scott
PS Your Kelsey character is awesome! I have purchased several of your products and all work great! Thank you for taking the time to comment on this thread, I've appreciated it.
Okay, I'm positive I got the hair to move. I was reading through the dForce guide here and came up with four parameters to change. So, I did. Here they are:
Friction default .010 new .001
Bend Stiffness default .20 new .010
Buckling ratio default 3.5 new .1
Density default 5000 new 30
Density is way, way high according to the guide.
The first time I tried this, dForce blew up. Reboot and start over. Right now, I've half split the settings returning Friction and Bend Stiffness back to their original settings. The simulation is halfway through right now, but it's taking forever. That's a good thing. If the hair is still blowing, I will set the last two back to default and change the first two back to the new settings and see what happens. If it still blows, I'll change them all back to default, then one at a time, I'll change them and see if the hair blows. Something tells me it's the Density setting: It's so far off from the guide. Then when I get to a good point, I'll bring the wind values down and see how things react. Right now, I've got winds ranging from 70mph to 0mph and back again. When I find the sweet spot, I'll tweak the settings to get the effect I want.
There may not be anyone interested, but that's cool. :) My foolishness is out in the universe and I'm having a blast!
Scott
With buckling ratio and Density set as above and the other two settings set at default for the hair, the hair moves rather nicely, but simulation takes forever and eventually crashed throwing a simulation error. Rendering was really slow, too. Now, with buckling ratio and Density set to default and the other two set as above, simulation took less than seven minutes for about 50 frames. The really interesting thing that happened this time is this: The Genesis 8 female figure disappeared!
I rebooted, resimulated, and re-rendered. This time, no wind effect on the hair with Friction, Bend Stiffness changed, and Buckling Ratio and Density set to default.
So, I'm going to set Buckling Ratio to default and change Density to 2500 to see what happens.
Edit: So far so good... the simulation is moving quickly. We'll see how render speed is.
Scott
With Density set at 2500 I got some natural looking hair movement, but the windspeed at that point was 90mph! So, I'm half-splitting again going to 1250 and see what happens this time around.
Scott
I tried to upload a short animation with the Density setting at 312.5--apparently the forum software doesn't like AVI's. :) So, 312.5 is where I'm going to leave Density. I wanted to get the hair to act like it had been hit by hurricane or really high-force wind and I have done it. Next steps are to adjust windspeed and test with longer hair. Also note that I rebooted after every half-split of the Density setting.
My takeaways from this exercise is basically this: The Density setting is way too high out of the box at 5000. It's effectively the only setting I modified.
Scott
Long hair, touching the shoulders is proving to be a problem. More banging my head against the wall and exposing my foolishness to the masses here. :) Gotta love it!
Scott
You could try uisng a morph to move the hair off the shoulders, then make sure the item is set to drape from its initial shape (Parameters pane under Simulation)
Thanks, Richard. I think I may have found the problem, but it was really late last night/early, early this morning. Basically, after simulation, the ends of the hair were under clothing--because of the way I set up the animation--a G8 female walking toward a single camera from distant to closer--I couldn't see it. I'm going to try different clothing after I fully wake up and see if that takes care of the problem. Dunno if anyone has had the problem before.
Scott
I think I've got it, now. I changed the figures shirt then half-split Density (GSM) until I reached 78.125. Long hair now blows. There's the side-effect of having Density at 78.125 is the simulation takes about twice as long as when it was higher. Interesting, though: The hair doesn't return to the original shape or anything close to the original shape. Maybe self-colliding? Friction? I'm going to take a break from this--life is a good thing--for a bit then check out what's going on.
If you look at other animations with Bang Bob Hair, the hair doesn't separate into strands--it pretty much moves as one. This is probably due to density and another parameter that remains unknown to me at this time.
Scott
Apparently, this forum software doesn't like .mov's, either. :)
So, some observations about dForce. If you'e gonna do multiple simulations, save your work and reboot between simulations--things will go much better. The software appears to have some memory corruption issues which only show up after you do multiple simulations, back to back to back, and so on. So, for these execises, I rebooted after every attempt. I have a fairly fast laptop (Alienware G4 17" UHD with all SSD drives) so rebooting doesn't take that long. The actual thing, dForce is quite cool! I've been playing with it for months following along with the blanket, stool, footprint, etc., stuff, but never this deep where things pop-up.
I think Bang Bob hair and the Classic Long Hair products from Linday are great, too. Could they use some tweaking? Yeah, but out of the box, they're great!
There are a couple of other dForce capable hair products I have that I'll play with in time. Right now, it's time to put what I've learned to use.
Scott
just reading al this and i know the adventure you are going trough a bit, i am trying to make my genesis 8 turn arround dancing with the bob hair, i lost count how many error i had.
for now i only do 1 frame simulation and just let it be for the rest of the animation, but i dont want that.
lowering the density is something i will try now.
Thanks for this thread! Though, I'm still stuck at getting the hair to move during animated simulation. All the settings seem right. When I simulate the current frame, the hair moves beautifully in the wind but when I try to simulate the animation, it doesn't respond to the wind anymore. What exactly did you do to make it work in the end? 'Cause I'm having trouble retracing your steps.
What I did? I just positioned the wind node so it blew on the figure at high speed. The problem is this: When this happens and wind velocity drops to zero or the character crosses through the wind node and out the other side, the hair stays blown. I've not figured out a way around that.
My goodness I wish I had read this earlier before wasting my money on two DForce Hair Objects. What is the point of buying any DForce product for animation, then having to do a pose by pose ani-render set up? If that is the case, then one might as well just use a stadard comformed G8 hair product.
In fact the whole selling point is how great and simpler a motion set up is for your sassy dress and hair animations, right?
I mean even the latest DazStudio allows for some interpolation between two hair poses or dress poses.
So I guess this answers my question as to why there appears to be no video showing you how to set up a hair or dress animation and certainly not both at the same time? As you have to set up each darn frame of the animation separately? right?
If it takes a long time (lots of frames) to transition from one wind state to another, maybe you need to render more fps. Or maybe you need more subframes (change in Simulation Settings). Would any of that help? I'm sure it would slow calculation down, though. Bang Bob Hair is not "real" dForce hair; it uses Linday's method of using dForce cloth settings for hair. It even states that on the product page. Maybe a real dForce hair would work better.
So an animation like this would take a day or more of rendering to do on a powerful computer?
looks great but is it practicle to try and do? Like I said better off with a conforming hair do with lots of morphs/poses and just adjust tem along the ani time line? I have done that with realy good results and short CPU time relative to what you are describing.
I assume dress movement for DForce is just as resource demanding?