Realtime HLSL Fur Demo (now includes Video)

[BlindSide]

I decided I wanted a little break from shadowmapping and such, so I spent the last day and night working on a little fur =).

There's nothing really special here, it's a standard shells-based method, but I think the results are pretty nice.

UPDATE - VIDEO: http://smithbower.com/old/fur/BFD.avi NOTE:6 megs, uses XVid

Click for a larger version




Here's the general idea...
Ideally, fur should be modelled physically in order to create the best effect. However, that would require an amount of detail not available to us in the realtime rendering world. Instead we must create an approximation.. so how do we do that? One way is to create partially transparent "shells" layered on your mesh, so that the visible sections of the shells appear to extrude from the mesh. If done right, this gives us the illusion of several fine hairs. Simple eh?

This implementation creates a "fur" texture for each shell layer, so with varying opacities so as to create "thinner" fur as the fur gets longer. By messing with the way the maps are generated, you can create a whole whack of effects, like curly fur, scraggly fur, fine/course fur, or having fur be shorter/longer/non-existant on different parts of the model.

Additionally, there is support for faked inter-fur shadowing - by creating additional fur shells with an offset, you get a bit more definition for each "spike".

Oh, and for the adventurous.. the shader code supports a force value to bend the fur. Could be used to create wind effects? I'm going to play with it a bit, I suggest you do too!

Beta users, download here: http://www.truevision3d.com/phpBB2/viewtopic.php?p=99531#99531

[Zaknafein]

Bloody hell this looks good. I'm amazed, as this is the first fur implementation I've seen in TV3D.

Great work Blind, as always!

[JohnB]

Uhm - WOW again BlindSide - that's just amazing!

John B.

[sgrippa]

Gosh, it seems there is a race between Blindside and Zaknafein to win the world championship in HLSL developement. :shock:

[WEst]

Looks great!

[Waterman]

Good work! Now furs are in TV3D.

[Rynus_Rein]

Looks cool! It's actually the second time I see fur in TV3D 6.5

[AriusMyst]

Blind did actually do fur ages ago. Not sure if he posted it before. I think this is his better version though, now he has more exp in HLSL.

[BlindSide]

Yup.. eons ago, I did fur. I think that was my second public demo/shader thing - but it wasn't very attractive. It was heavily based off the Nvida sample. I think there's a screenshot of the tiger still in the 6.5 screenshots section.

This fur is much better =D

[Happy]

WOW!! Blindside thats just mad awesome man, I didn't think many shaders were compatible with TV3D65 after I tried 7 apps with HLSL, GLSL and CG support.. I've only manage to get 9 shaders to work... but none like youre's or Zaks. Impressive work guys keep up the good work, Also Blindside good luck with the shadowmapping demo man.

Seeya Later!

[BlindSide]

Thanks Happy, the demo is coming along slowly =D

Any DX compatible shader will run in TV, since TV uses DX's shader engine. The tricky part is that most complex shaders, such as fur, or shadowing, require a fair mount of application work as well as shader work. This is where more problems arise - even when you copy straight from a DX demo. It really isn't easy to simply port someone's code, there are a lot of small things that tend to get in the way.

[AriusMyst]

It really isn't easy to simply port someone's code, there are a lot of small things that tend to get in the way.

Hehe, yea. A good example of this is actually Blinds fur shader. I've spent all day trying to port it. Neither he nor I had any idea why its not working  :wink: .

[Slider]

Here's the original shader, for those of you interested:

http://www.xbdev.net/directx3dx/specialX/Fur/index.php

I don't think you mentioned it is based on an existing shader demo?

[BlindSide]

Here's the original shader, for those of you interested:

http://www.xbdev.net/directx3dx/specialX/Fur/index.php

I don't think you mentioned it is based on an existing shader demo?

Aye, thanks, forgot to stick that in =)

The original code is based on the tutorial on that site, which explains things a lot better than I did, however I was never able to get it to work, so I'm not sure how my implementation compares to his - I don't know how he does the curely fur, though I would imagine he offsets his depths maps by a smidge for each layer to create a jitter.

[Slider]

Here's the original shader, for those of you interested:

http://www.xbdev.net/directx3dx/specialX/Fur/index.php

I don't think you mentioned it is based on an existing shader demo?

Aye, thanks, forgot to stick that in =)

The original code is based on the tutorial on that site, which explains things a lot better than I did, however I was never able to get it to work, so I'm not sure how my implementation compares to his - I don't know how he does the curely fur, though I would imagine he offsets his depths maps by a smidge for each layer to create a jitter.

Well, the curly effect is done by manipulating the vertex shader.
Here's a way to do it to create, for example, waving/curly fur (non TV):

Code:

// Apply swaying
    IN.position.x  += cos(SwayXNoise * fSeconds * SwaySpeed) * sin(SwayXNoise * fSeconds * SwaySpeed) * SwayIntensity * (a_Layer * a_Layer);
    IN.position.z  += sin(SwayZNoise * fSeconds * SwaySpeed) * cos(SwayZNoise * fSeconds * SwaySpeed) * SwayIntensity * (a_Layer * a_Layer);

I've been using something similar to create waving grass:

[Zaknafein]

Oooh, sexy.
It's been a while since we heard/saw stuff from you Slider, welcome back!

[Slider]

Oooh, sexy.
It's been a while since we heard/saw stuff from you Slider, welcome back!

Thanks! I've been quiet busy lately so I haven't been around much
I'm working as a programmer for a game company now (actually, it's already been two years by now), so I'm legally allowed to play with the big engines now

[Raul]

wow.. this rocks

nice effects..