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View Full Version : General Lightwave headaches- need solutions



TaylorCaudle
08-16-2017, 06:46 PM
Okay so here's what I'm struggling with-

I have off and on success with parenting Deforming objects to collision Nulls, and getting them to move with the bull (ala a Cape, or scarf, or robe).

I achieve this by creating a collision Dynamic, making it a sphere, setting it to Stick mode,
Then making it a Bullet Kinematic, and setting the collision margin large enough to "grab" the part of the cloth I want it to stay fixed too.

SOMETIMES this works perfectly- cloth stays and behaves like a cape, moves with null as it flies around.
Most of the time, the cloth just stretches off into infinity, or slips off the null, or just falls through the floor.

I've compared all my successful scenes to my non successful ones- nothing is different. Literally all the same input.

Also, whenever I make collision objects and parent them to BONES, to make the cape or robes deform with their movement- it works FINE if the character is stationary.

If the character moves, or runs, or uses IK Boost at all,
The collision objects "lag" behind the mesh, as in the character moves forward but all the collision child objects are about 1meter behind the character. For no reason.

Anyone have any experience with these issues? Really pissing me off, I love Lightwave but I'm getting real sick of things doing weird **** for no reason.

Surrealist.
08-17-2017, 01:30 AM
I am not a Bullet expert. But what I have seen and heard it seems counter intuitive for character work.

But someone with more experience could help more.

I find classic cloth Fx as far more useful for characters. And better looking. However self collisions don't work.

So it is a trade off.

Kryslin
08-17-2017, 12:08 PM
Let's see if I can make things worse... :)

This is from my experiments of Character -> Clothes -> Long Hair guides...

I used deforming objects; Yes, it's slower, but the results were more predictable; I couldn't get things to work properly with kinematic objects.

Shape Lock is key for items driven with bones; setting it to translation and rotation allow bones to deform the object.
Shape Retention allows you to lock certain portions in place; by using a gradient driven by a weight map, you can fine tune where and how much dynamics are applied. I do not recommend going completely to 0% - 5-10% is usually good enough. You will have to play with the stiffness settings and damping to get it just right...

I also recommend using a low polygon collision hull or Bullet's basic shapes. Using your character mesh can cause some painfully long simulation times.

Also, you can't have 2 dynamic objects interacting with each other. (hair <-> Clothes); you'll have to bake the lowest layer (clothes <-> collision hull), remove bullet from that, apply the mdd file to the clothes. and then apply dynamics to the hair (so I've been told).

TaylorCaudle
08-17-2017, 02:37 PM
I honestly cannot get Clothfx to work AT ALL.

Seems to do absolutely nothing, even when I Calculate it the mesh just falls straight down, doesn't deform at all. Seems to have no effect.

Also making the object Deforming is useless without a Kinematic underneath, as it'll either fall through all the Meshs or just slide off.

I'm trying to A) get my collision nulls to move with the bones they're patented to,

AND get the deforming cloth to follow the parent null.

I now use a weight map to deform everything but the "collar" area,

But generally it's hit or miss. Can't figure out why it works only 50% of the time.

ALSO does anyone know what's causing my deforming body to STRETCH, and make little holes in the cloth?

Sometimes it behaves like a cloth, other times it stretches off. Isn't getting caught on a rigid or static object, it's falling trough the floor but still stretching

Surrealist.
08-17-2017, 04:58 PM
Can't help you with Bullet. But regarding the cloth Fx I could get it working for you in minutes. I will be in a meeting soon. So it will have to be later. I will dig up some links.

erikals
08-17-2017, 05:08 PM
check this video >


https://www.youtube.com/watch?v=qRh2Jpl4_Vk

erikals
08-17-2017, 05:13 PM
also see >


https://www.youtube.com/watch?v=LFuJQMPc9HY


in general ClothFX can be a bit tricky, and does not have "true" self collision.

erikals
08-17-2017, 06:50 PM
maybe some of these settings could be of help, sorry couldn't find any jacket scene >


https://www.youtube.com/watch?v=_OvBcJhWWpg


tweaked LW9 file, added wind for fun...

Surrealist.
08-18-2017, 01:33 AM
Follow the Yellow Brick Road...lol

Start here:

http://forums.newtek.com/showthread.php?126804-Just-Clothes

Links to here:

http://forums.newtek.com/showthread.php?115743-Cloth-Tutorials

And in particular this post here:

http://forums.newtek.com/showthread.php?104570-Help-Surrealist-Feel-like-ending-it-all&p=963836&viewfull=1#post963836

Other posts contain other info as well.

Seems I deleted the Vimeo vid. Here it is on YT:

https://www.youtube.com/watch?v=XOu2zcPeDzU

Danner
08-18-2017, 03:42 AM
The one thing that tripped me at first was scale. Simulations are sensitive to scale, too big or too small doesn't work.