Nvidia apex clothing tool - make collision for hair

[RedstarBelgium]

Greetings everyone,

I looking for to use Apex Clothing tool for hairs in Unreal engine 4. I’d like to know how can I collide the hair’s faces with a character. I have configured the Max distance and the Backstop but i don’t understand how to make the character as collision.

The goal is the hairs musn’t overlap the body.

Can you help me ?

[Geodav]

you have to add the collision in the apex tool, Blender Apex UE4 Cloth Update 2015 12 20 - YouTube
never tried it on a character so no promises that it will work

[ULLS]

[video]https://drive.google.com/open?id=0B3xUj4Hq1BbleDZ6ZGdiQWczdFU[/video]

I did this simply by painting max distance and backstop without setting-up any collision volumes within the tool (use one or the other…not both)

I set the value of the backstop to 0 when painting the backstop.

I did experiment with using collision volumes instead but I found the backstop gave a much better result.

[RedstarBelgium]

Geodav, I see you configure two collisions “bones” to the stick of your flag. In my hairs, i have a “skeleton”. It doesn’t work.

ULLS, It’s interresting but i need more precisions: how have you done for have this result ? I don’t understand why you can done this and not me.
And what value of the backstop is to 0 ? Painting i suppose ?

For a mesh of hairs, should I parent an armature with it or can i use it like a “Static mesh” ?

[ULLS]

@RedstarBelgium;650524

Geodav, I see you configure two collisions “bones” to the stick of your flag. In my hairs, i have a “skeleton”. It doesn’t work.

ULLS, It’s interresting but i need more precisions: how have you done for have this result ? I don’t understand why you can done this and not me.
And what value of the backstop is to 0 ? Painting i suppose ?

For a mesh of hairs, should I parent an armature with it or can i use it like a “Static mesh” ?

I’ve not done anything special here, I simply used the backstop according to the Apex Clothing Tool documentation

In terms of precision, you’ll need to paint the backstop with a value of zero. You wont get any greater precision using collision volumes, in fact the precision would be much worse actually. The reason the hair on my model doesn’t look great is simply because the hair model hasn’t been designed for this use case. I could easily get a better result by designing the hair with Apex cloth in mind.

The character you see in my video was generated and rigged using Mixamo Fuse and their cloud based rigging service but the hair itself is essentially just a static mesh and has no ‘hair’ bones although it would have been automatically vertex skinned to the skeleton in Mixamo’s auto rig process so make sure you’ve skinned the hair correctly.
Here’s a step by step guide of how I did it…

1. Open the Apex Clothing Tool
2. Selected only the hair submesh
3. Clicked the generate tangent space button
4. With backstop selected, painted the entire hair mesh with a value of zero
5. Painted the Max Distance on the areas of the hair that I desired to move
6. Tweaked some of the physics sim settings to suit (i.e. gravity scale)
7. Saved the file and loaded it into UE4.

As I mentioned earlier, I had also experimented using collision volumes instead, however It didn’t work very well for hair and backstop was the better of the two options.

Here’s another [video]https://drive.google.com/open?id=0B3xUj4Hq1BbldHRKcU81OTJ5dTg[/video] of the character in game.

[RedstarBelgium]

Ok, it’s almost done but there is something I don’t understand:

First, the max distance:

Them, the backstop:

Finally, the result:

The mesh doesn’t supposed to collide with body mesh ? I need to configure the scale point manually ?

If it’s the second option, it’s like a fake simulation collision, them? So i suppose if i use the hair’s armature as collision (or “Ragdoll”), this is less economic about the engine performances ?