Overgrowth takes place in the savage world of Lugaru where rabbits, wolves and other animals are forced to use paws, claws and medieval weaponry to engage each other in battle. Combining 3rd person adventure platforming with intricate melee combat, Overgrowth achieves a unique feel. Overgrowth also benefits from Wolfire's brand new Phoenix Engine which has been built from the ground up to allow the use of cutting edge graphics, animation, and physics. Add to these exciting features Overgrowth’s realistic artificial intelligence and streamlined control system and the result is an astoundingly immersive experience.

Report article RSS Feed Soft normal maps for fur

The rim lighting shader went a long way towards making the fur look soft when lit from behind, but it still looked hard when lit from the side. This problem is so prevalent in modern games that I've started referring to it as "plaster-hair syndrome" -- when hair or fur is sculpted with great detail, but lit as if carved from plaster.

Posted by jeffr on Oct 20th, 2009

The rim lighting shader went a long way towards making the fur look soft when lit from behind, but it still looked hard when lit from the side. This problem is so prevalent in modern games that I've started referring to it as "plaster-hair syndrome" -- when hair or fur is sculpted with great detail, but lit as if carved from plaster. This lighting problem is visible on the rabbit's chest here:


What we're missing is a form of subsurface scattering. Fur is translucent, so no individual clump of hair should be opaque enough to produce such sharp shadows. Aubrey and I had discussed a technique for painting soft fur earlier -- blending the fur with multiple blurred copies of itself. This softens the lighting without losing the tiny surface details. If that works for paintings, why not apply that to the normal maps and see if it works in 3D? On the left is the original normal map, followed by two blurred copies, and then the final composite. The final composite is made by taking the original normal map, and layering both of the blurred copies on top at 50% opacity.


By assigning different weights to the blurred normal map copies, we can control how soft we want the fur to look. Here we have three different versions, from hard to soft. If you click to zoom in, you can see that even the softest option still has the fur detail intact.


So does this solve our problem with plaster fur? Let's see how it looks when it's all put together! On the left is the original image from the start of this post, and on the right is the softened version.


Here's the same scene lit from above.


I think that the softened normal maps really help solve the 'plaster' look, and it achieves that with no effect on framerate! It's always nice when we can make Overgrowth look better without using any extra computational resources. Can you think of any examples of games that effectively render fur or hair without using powerful hardware? Some of the most inspirational to me have been Shadow of the Colossus and Final Fantasy XII. (permalink)

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AJ_Quick Oct 20 2009, 10:34pm says:

most of Overgrowth's graphical news flashes are "well known" , i think they just enjoy sharing their engine with the public :)

+4 votes     reply to comment
jeffr Author
jeffr Oct 20 2009, 10:41pm replied:

We are going to submit each of our ModDB news updates as papers to SIGGRAPH 2010. The graphics community won't know what hit them!

+1 vote   reply to comment
SneakySoft Oct 20 2009, 11:52pm replied:

If they read this moddb page they will :P.

Nice work on everything you guys, are you also working on gameplay or is this just an engine? because i would realy like to see some gameplay prototyping work

+1 vote     reply to comment
Silverfisk Creator
Silverfisk Oct 21 2009, 7:24am replied:

I think it will come when they start developing the gameplay more, but they've written about it earlier. And had a fighting prototype in the engine earlier.

+1 vote   reply to comment
Daystranger Oct 21 2009, 1:00am replied:

You're trying to be smart, don't you?

Its NOT "flashes", its their "how-we-do-stuff" posts.

+1 vote     reply to comment
Joe_Shmoe Oct 21 2009, 6:49am replied:

It may be well known to those who specialise in that field, but as a mapper, writer, concept artist and project planner, alot of these tricks are new to me, its still interesting to know how most things in new technology works even though i dont specialise in it =]

+1 vote     reply to comment
Dragonlord Oct 21 2009, 6:50am replied:

Nope, it's called PR-Whoring ;)

-3 votes     reply to comment
jeffr Author
jeffr Oct 21 2009, 2:02pm replied:


+3 votes   reply to comment
death_fly Oct 22 2009, 1:59am replied:


0 votes     reply to comment
Nebcake Oct 20 2009, 10:55pm says:

It looks amazing.

+1 vote     reply to comment
AJ_Quick Oct 20 2009, 10:56pm says:

Well if you spend as long on designing fun gameplay, as you have on shader tweaks, you might be on to something. I'll keep my eye on Overgrowth

-3 votes     reply to comment
Eegah Oct 20 2009, 11:13pm replied:

They've already proven they know fun gameplay, go look at Lugaru or even Black Shades, there's lasting appeal I don't see in a lot of other places.

+5 votes     reply to comment
draken1991 Oct 24 2009, 10:02am replied:

Black Shades was a game by Wolfire? Man, even though that game was extremely simple, it was fun as hell.

+1 vote     reply to comment
chris_sloany Oct 20 2009, 10:57pm says:

looks a lot more natural! good work!

+3 votes     reply to comment
Eegah Oct 20 2009, 11:08pm says:

There's a great article online of the making of SotC, was surprised to see how much they seemed to work with LightWave.

Other games? I'd say Peter Jackson's King Kong did a really nice job on the fur effects without crippling performance, I think it scaled pretty well from low end to high end systems too.

+1 vote     reply to comment
christensenct Oct 21 2009, 1:24am says:

Is that a bit of cancer keeping the rope on his shoulders down?

+3 votes     reply to comment
Silverfisk Creator
Silverfisk Oct 21 2009, 7:26am replied:

I think it's fur.

+2 votes   reply to comment
PringleX Oct 21 2009, 1:32am says:

Good work again. As always!

+1 vote     reply to comment
Arparso Oct 21 2009, 4:07am says:

When I think of fur rendering, I immediately tend to think of "Conker - Live & Reloaded" on the original Xbox. Considering the age of that particular hardware, Conker's fur and that of his enemies was really impressive and ran very well performance-wise. Easily one of the Xbox's most advanced titles in terms of graphics. I'd like to see a similar method used in Overgrowth, because the blurred normals might look better than the original rendering, but they're still way too flat to actually look like fur.

+2 votes     reply to comment
formerlyknownasMrCP Oct 21 2009, 6:23am says:

You know what would be EPIC! Animating them- just a small amount.. just enough to notice that the fur moves slightly due to small wind.

I think due to how close up you'll be getting in the game if you were able to notice those little details of fur actually moving around on a texture, it'd just bring everything to life a lot more. That said it could be a bit of a challenge.

I think you'd get more of a feeling that its fur if it moved just a small bit- at the moment it looks more like Rock due to how static it is. Just a suggestion.

that said though, it looks amazing.

+2 votes     reply to comment
Joe_Shmoe Oct 21 2009, 6:54am replied:

i agree with this, im guessing it will be third person so most other characters you wont realy get very upclose and personal with, however the player character should have this kind of detail, animated fur =] im totally with this

+1 vote     reply to comment
Minuit Oct 21 2009, 7:11am says:

If only games companies bothered with fixing small annoyances as much as you guys do...

+2 votes     reply to comment
nubblecakes Oct 21 2009, 12:44pm says:

Have you guys considered implementing the fur shader? At least for the tails or something. That could look really good.

+1 vote     reply to comment
sbnewsom Oct 21 2009, 6:27pm replied:

The fur shader is absolutely horrible when working with realistic themes. The only times it worked effectively was in cartoony games such as conker. I say don't use the shader just for the sake of it. Unless it looks like Hair Shaders from Maya or Max, just don't bother.

+1 vote     reply to comment
Myloman Nov 3 2009, 7:11am says:

Hmm, this is an interesting issue to tackle. The softening definitely makes a significant difference, and hopefully you'll find a solution to make fur stand out from the body slightly if possible. Either way, great work!

+1 vote     reply to comment
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