How Are Games Rendering Fur?

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It's easy to understand why fur is extremely problematic with its high density of objects and physical complexities, but somehow games have been rendering it for years! How could something so complex be so easily simplified?
Topics covered: Hair and its rendering complexities, shell texturing, half lambert, shell texturing applications, limitations of the technique, and overdraw
Code: github.com/GarrettGunnell/She...
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Resources:
hhoppe.com/fur.pdf
xbdev.net/misc_demos/demos/fu...
thegamedev.guru/unity-gpu-per...
www.gamedev.net/forums/topic/...
Music:
Afternoon Break - Persona 3 OST
This Mysterious Feeling - Persona 3 OST
Midori Eyes - Paradise Killer OST
During The Test - Persona 3 OST
Junes Theme - Persona 4 OST
Every Day Is Night - VA-11 Hall-A OST
Underground Club - VA-11 Hall-A OST
Those Who Dwell In The Shadows - VA-11 Hall-A OST
Your Love Is A Drug - VA-11 Hall-A OST
GO!GO!STYLE - Paradise Killer OST
Joy - Persona 3 OST
Sandgem Town - Pokemon Diamond OST
Like A Dream Come True - Persona 4 OST
Layer Cake - Persona 5 OST
Prof. Omochao - Sonic Adventure 2 OST
Thanks for watching!
This video is dedicated to my friend, Alotryx.
#acerola #graphics #gamedev #unity3d #graphics #shaders

[@Acerola_t]

Get an exclusive @Surfshark deal! Enter promo code ACEROLA for an extra 3 months free at surfshark.deals/acerola #ad Thanks for watching!!

[@Levi1440p]

can we all just appreciate Acerola's genius idea in using a double video, a technique that emerged with the advent of tiktok and quick videos on social platforms as a method of hooking the audience using super stimulation techniques so that people don't skip videos that might seem uninteresting on their own (like an advertisement)? very well thought out and implemented, with the use of a race that dominates the internet. genuinely brilliant and honest, so good in fact that I didn't skip an ad for the first time in a long time. thank you Acerola, thank you.

[@releasemeeee]

Hey Acerola! Great content so far! Really look forward to your take on how glass works in games, this had been the most daunting topic for me as a videogame artist 😟 Would be a blast if you showed how to deal with it and achieve best results. I personally haven't achieved even a somewhat adequate refraction behavior in years I've been into Unreal 🙃

[@binkbonkbones3402]

I want to make a mobile game where the galaxy is full of basically dandelions that float around instead of planets, and each sphere can be traversed like mario galaxy Could you maybe do a video on how to do gravity that connects to bodies in space instead of indiscriminately falling down? Also, I'm curious if I could just declare a point in space, and project these shell texture grass effects in all directions from there? Also, by extension if I can declare one point in space can I also declare a distance from that point representing the circumference of the body in space and creating the ground? Not gonna lie, it would be pretty ideal if I could just render each body is space as a basic point in space, and move them around from there Also, I just realised the directional tilting could lend itself well to an effect of being like the tail of a comet giving it it's distinct flaring light look Also, how do you think the smoke effects you previously spoke of would apply to stuff like nebulas and space clouds? Does it scale well? I want it to have a very "cosmic ocean" aesthetic, and making big areas of space different colored clouds would be cool

[@DarkerCry]

Just wanted to say this is a super useful video, really appreciate that the code is also available. Especially for the fake physics.

[@zyth8241]

Shaft studio?

[@m_remon]

God I just realized he's wearing more layers as time passes. Amazing.

[@Yixdy]

Dude, spoilers

[@mmiles9734]

​@@Yixdystill opens comments before watching video 😅

[@PaulFisher]

And some pretty good bands among them too!

[@ashtoncartner]

I watched the entire video without realising even once

[@AB-Prince]

one technique I've seen to hide the gaps between shells, is to distribute the shells such that the gaps are bigger at the bottom and smaller near the top. as the denser lower layers do a good job of masking the gaps but the upper sparse layers need denser layers to hide the gaps

[@Acerola_t]

This functionality is in my shader code I didn't expressly mention it tho

[@ludfde]

Couldn't you slightly offset the normal of the quads using noise?

[@KillahMate]

@@ludfde Instead of being randomly offset, wouldn't we always want the normals to slightly face the camera?

[@AB-wf8ek]

I wonder if there's some aspect of gaussian splatting that could be applied. As far as I understand, it's using blurry splats that take camera position into place to replace the points in a point cloud. Perhaps blurry shells that also take into account camera position?

[@tonygamer4310]

@@ludfde unfortunately no. That operation has to be done in the vertex shader pass, and each layer only has four vertices, so you could only apply it to the very corners of the grass, not to each individual blade. If you wanted something like that, you'd have to find a way to bake it into the pixel rendering shader, which would get extremely complicated very quickly

[@SaadTheGlad]

These videos are genuinely one of two things I look forward to on KZbin, the other being Sebastian Lague videos. Great stuff.

[@Superhirn]

same

[@wack9175]

Sebastian Lague my beloved

[@deadsince1996]

and Stuff Made Here.

[@Adam-zt4cn]

Code Parade is one I can recommend. He is another great example of this style of technical, but beautifully explained coding projects.

[@_jax]

Yess

[@evilotis01]

1:40 "a game with a protagonist with a beautiful head of hair but gets [transported?] into a universe where everyone is bald and is trying to kill them with having hair" and that was how Acerola made his fortune

[@MathewAlden]

The word you're looking for is "isekai'd". But "transported" is a fair synonym.

[@DoktorBeta]

literally just the world of Bobobo-bo Bo-bobo

[@dreckneck]

As a guy with long hair entering my thirties, this is an accurate description of my life imo

[@TalynStormcrow]

Brave video game, all the enemies are helmeted warriors. The end boss is a bear that glitches the game out but you use the glitches to defeat them.

[@glowstickspinalfluid]

i am incredibly bored so i'm gonna be a massive nerd for a second. isekai is a popular genre of anime, where a character is magically transported into another universe. the method of transportation is usually the character getting hit by a truck and a god taking pity on their untimely death. the popularity and weirdness of the genre gets it a more emotional reaction than just "transportation"

[@julianlanty2066]

I imagine Acerola in a party corner like "they dont know how to render realtime hair"

[@tsbohc]

Oh, so that's why Sif is like that. Might be just me, but the uncanny look of the fur actually makes Sif look almost ethereal. I bet you could use this to intentionally trigger an uncanny valley effect when designing some otherworldly creatures. Neat stuff!

[@512TheWolf512]

This is the actual good way to utilize phycologists in game dev, instead of using them to figure out how to further exploit people prone to gambling addiction

[@lordanonimmo7699]

In the original dark souls the gaps were more subtle,the lighting was hiding it better but in the remaster version he shows the lighting makes some parts darker wich makes the difference way more visible.

[@LanceBerylDev]

Nintendo particularly has really gotten really good at shell texturing across a ton of their recent games, particularly with the rendering of fur on characters like Donkey Kong. Fun fact: Super Mario Galaxy 2 (for Nintendo Wii) was originally going to make prolific use of shell texturing for its grass; which was showcased in various early development/promotional screenshots. -However come release, nearly all shell texturing was removed from the game. Why this was done I don't believe was ever specified.. it may have well been due to performance or technical complications, ..though personally I believe the more likely answer is that the team saw the effect as too uncanny applicated in this specific instance, and jarringly dissimilar from the presentation of grass in the first game, so it was scrapped (outside of a few one-off planetoids.)

[@myrealusername2193]

I think they learned a lot from making nintendogs lol, fur on low power devices is hard

[@WackoMcGoose]

Paper Mario TTYD used a similar method (not _procedural_ texturing, just layered textured shells) in quite a lot of areas. The flower beds in Boggly Woods, and the carpeting in the Glitz Pit Champ's Room come to mind...

[@MizoxNG]

they still used it for the Bee Queen in both galaxy games

[@romajimamulo]

Adding on a prior comment, both galaxy games use shells for the bee fur.

[@LanceBerylDev]

@@romajimamulo oh yeah truue

[@puckchang8691]

Viva Piñata’s grass may be just a visual trick, but you can’t imagine how much I wish I could just lay down in it. It always looked so soft! You can tell me that I need to go outside and touch grass, but the only thing I really want is to touch THAT grass!

[@Mine4Caft]

same

[@Superhirn]

I actually don't understand that much of what you say but it's just fun to see you magically combine values into complex lighting models (:

[@Budder99]

Same

[@StkyDkNMeBlz]

One day

[@missmia196]

I just love hearing nerds talk about topics that interest them 😂

[@512TheWolf512]

All complex things are just a collection of simple things

[@gdog8170]

I think one can do it by just using black values as transparent pixels

[@congobongoproductions5476]

Can't believe no one is mentioning this bit at 19:35 saying "...what's basically a layered cake of meshes" while "Layer Cake" is playing... Masterfully done 👏

[@juanalbano140]

Planet Zoo has an amazing fur system too for LOTS of animals. I'm not totally sure but it also looks like shell texturing, but it looks good even on grazing angles!

[@Gorialis]

I'd like to also say about the Half Lambert solution - one of the reason it works so well is because hair is, as you say, transmissive. Real hair has light pass & refract through it, so any part of a contiguous set of hair that is in total darkness will look really weird since it's nearly impossible in most situations with a light source. Half Lambert fakes the indirect lighting you would get from a path or ray-tracing lighting model even in a forward rendering environment, so it feels more natural.

[@MizoxNG]

I remember being absolutely blown away by this technique back in 2002 when it was used in Star Fox Adventures. and again in 2005 with Conker Live and Reloaded... funny, Viva Pinata had the same devs as both of those.

[@stevethepocket]

Definitely looked better in StarFox. With Conker it looked like someone had rubbed a balloon all over him. I think it's because they put less effort into refining it. In StarFox it was really only used to render Fox's tail, except during closeups in cutscenes where they applied it (on a much subtler level) to his head as well, so they could focus on making it look as good as possible where it mattered.

[@curtfehr]

I’m still blown away they pulled it off on a GameCube. Rare had some real technical wizards back in the day, making consoles do what they aught not to have been able to do.

[@MizoxNG]

@@curtfehr i mean the gamecube's pixel fill rate was apparently high enough that it could do 34x overdraw while maintaining 640x480 @ 60 fps. That overdraw factor is the important part when it comes to this effect, so yeah it was completely practical on the hardware

[@nickybakes]

Our game, Steel Heel Jam, has a non rotating, almost top down camera, and while watching your live streams I realized this would be a cool addition to the environment art for some grass. I plan to easily add some basic vertex animation with a noise texture for wind on the grass.

[@snbv5real]

I would advise you to look into raymarching grass ShaderToy instead (it look up "grass field with blades"). This technique is outdated, slow, and a pain in the ass to set up comparatively.

[@VetNovice]

Another Acerola banger? You can't be fur real! I've worked with fur throughout my life in 3D, seeing such clever, concise techniques here gives me an incredible basis / tool kit for this. Thanks again, king. 👑

[@addiment]

> what is basically a layer cake of meshes > Layer Cake - Persona 5 well done

[@nullvoid3545]

When I was looking into methods for making efficient imposters for voxels, I found A technique called inverse frustum mapping which inspired an idea I have yet to implement. So if you take A screenshot of A surface with both A regular and inverted frustum then blend them based on camera position, I think it may be possible to render the sides of depth mapped objects in ways that shells cannot because the texture isn't being mapped orthogonaly.

[@DiThi]

I think a similar technique is frequently used where you just render a depth pass with flipped normals, so you have the depth of the opposite side of each mesh.

[@haiperbus]

why are you capitalizing "a"

[@rafertysullivan6085]

I know next to nothing about graphics programming but these videos are always so entertaining

[@_OpenJournal_]

This has become one of my favorite KZbin channels. I don’t have any interest in creating games or other things that require real-time rendering techniques, but I have a deep love for video games (although I don’t really play anymore). 30 minutes of extremely well articulated, concise, funny, and entertaining explanations to technologies and concepts I knew nothing about draws me in. This is what the internet was made for: experts of their craft sharing knowledge publicly. Even if I’m not going to internalize this information so that I can create with it, it’s beautiful to learn about the foundation of how things work and it brings me happiness. Keep sharing mr. Rola! You’re inspiring!

[@missmia196]

You verbalized why I love the Internet! Free expert knowledge everywhere!

[@morgan0]

17:23 another way to do this is to lerp between last frame’s value and the whatever new value by some small amount. technically it’s dependent on the frame rate so maybe do that in the physics update and then a bit of smoothing in the per frame update, or calculate it every time. the benefit of this tho is that it’s an exponential approach, which feels very natural. it’s a first order lowpass filter, and eventually i’d like to make a video going thru it in depth because it’s a really good way to smooth things and i’ve been using it a lot in my game to make things smoother, and i think more people should know about it for game use.

[@bigchooch4434]

These videos give off huge high school project presentation vibes with all the clipart (in the best way possible) and I absolutely love it

[@hughjanes4883]

Ive ran into plenty of rendering issues with hair, it can cause some really *hairy * opacity problems. Ba dum tis

[@flux1940]

24:43 THIS IS THE REASON why old Dark Souls bosses with fur brought my laptop always to lagging when i moved the camera close in ! Now i finally understand. It never made sense to me that when the camera got stuck on the groin of the taurus demon that my pc almost crashed.

[@KoshakiDev]

This technique reminds me of sprite stacking. A good example is NIUM. It is used in 2D games to simulate a 3D object without actual 3D graphics. Instead of layers being randomly generated, they contain "voxel" layers to represent a model. This would mean that the higher the object is, the more resource intensive it becomes.

[@mileskosik472]

Not much of a gamedev person myself, but I have always wondered how shell textures work, and this video explained it super well! Great video, I would love to see how nvidia hairworks and AMD tressfx works!

[@Dundere_de_Duke]

Acerola, have you ever heard about particle rendered hair? I heard about the graphics of pikmin 3 a while ago and one of the bosses uses this technique to render fluffy fur from partickless that are locked to dark unseable areas of the texture. It's very interesting stuff

[@Acerola_t]

yeah, it's a more expensive solution to the geometry problem, definitely really cool that it even works on the switch

[@yellowpie]

I came across this video right before the final for my Intro to Modern Graphics Programming class, where I had to research a graphics programming technique and give a mini lecture on it. I only covered about half of what this video does, but it was a pretty fun experience, and while I’m more of a game designer than a programmer, I’m starting another graphics programming class today and I’m excited to learn more! Thanks for making these videos and keeping me curious about graphics programming!

[@Levi1440p]

please Acerola, keep making frequent videos because I keep looking for your videos to watch, such quality 😭

[@dimitribarronmore]

I've seen something similar to shell texturing used in 2D as a method of creating nearly-3D voxelized objects in low-resolution games. By generating vertical slices of a given object and drawing them from lowest to highest with a gradually decreasing Y value between layers, sometimes as small as a single pixel, the slices stack on top of each other and appear to build depth. This creates an effect which is something like front-on isometric perspective, because if you rotate the slices around a common origin so that every part of the image remains in the same relative location it creates an illusion of a three-dimensional object spinning but always maintaining the same 45-ish degree angle relative to the camera.

[@superbro6413]

I like to imagine Acerola is a senior graphics technician at Nvidia or something and just every so often releases youtube videos on his off time haha

[@KingBobXVI]

He's talked about it in previous videos, he _was_ an engineer at nVidia, and left (quit or was laid off, I don't remember) not too long ago and decided to focus on youtube videos.

[@Acerola_t]

I was a graphics programmer for Intel and PlayStation before quitting to do this full time

[@superbro6413]

@@Acerola_t Well hot diggity! That explains how you are so well versed in all of this Always enjoy your videos, and I appreciate that you don't shy away from the intense "formulas and calculations" side of "how do I make this look good" lol Thanks again for the video ✨

[@temotskipuri3151]

Nah Nvidia wouldn't use all this el cheapo flawed stuff. I mean they're pushing realistic lighting with ray tracing, and this technique directly contradicts that, as shown in the video.

[@edge4694]

I like the detail of having the background song being "Layer Cake" while talking about layer cakes at 19:33

[@lydianlights]

Another amazing video! I feel like this is one of those things that I will see EVERYWHERE now that I know to look for it. Very excited to participate in this challenge. Love that you're encouraging people to do homework and learn the material :3

[@TheForbiddenLOL]

20:10 >If they didn't fix it, you don't have to either! Perfectly said! Tech art is all about compromise lol

[@mgostIH]

Regarding RNG in GPUs, what do you think about the paper "Parallel Random Numbers: As Easy as 1, 2, 3" by John K. Salmon et al., which seems to be an approach close to the hashing method you describe, but their implementation is pretty damn good statistically.

[@Acerola_t]

I'll check it out!

[@mgostIH]

@@Acerola_t happy you've seen this comment, I know about it because in deep learning the Jax framework uses it to generate random numbers. The core idea comes from counter mode ciphers, where a seed + counter allow you to get a block of random bytes. The seed remains fixed across the generation and you only need to increase the counter over all the blocks!

[@assiuq]

You're probably the only KZbinr whose ads I don't skip. That cat cam is pure genius!

[@TheSliderW]

Its nice to see an in depth examination oh this effect. The first time I've seen it was in a magazine that covered the release of shadow of the colosus on PS2. But I also noticed this effect used in Starfox Adventure on the GameCube. Another game from Rare. Pretty much all their games used this effect. That being said, I don't think triangles arw that big of a deal on modern hardware, you could probably get away with blades of grass using 5 vertexes and using various mesh instamcing techniques. This would give tou multiple benefits like proper shadow casting, culling and no need for expensive pixel shading or pixel transparency testing. You probably wouldn't be able to get the same density or long distance views but that calls for additional visual tricks too. Note, tou kept saying this was and still is commonly used but apart from a couple of AAA console games and Breath of the wild clones, I have mostly seen crhe classic X grass. Does anybody know of other games using this technique (outside of small indie projects )

[@darjanator]

Funny timing. Just last week CIG, the makers of Star Citizen and Squadron 42 had a panel at the annual event CitizenCon where they showed off how they're rendering hair.

[@darjanator]

Are links allowed? kzbin.info/www/bejne/oX23i5l3mMZ9psU

[@mochou-p]

we all appreciate how long it took you to record this, you even grew clothes over time

[@RonWolfHowl]

Darn, I wish I’d had the time to do this challenge!!! I hope you do others like this in the future, I like the idea of “shader jams” where people try to improve on an existing technique. What a great thing to use your influence for!

[@JMW1906]

Unfortunately i don't have much time in the next weeks, but here is what I'd attempt to improve rendering: Get rid of shells entirely and only jave a single outer shell. Then, in the fragment shader, use the incoming "ray" direction (i.e. the angle to the camera plane) and the position (UV) to know through which shell pixels the ray will travel. Then go through these, stopping when hitting the first grass and perhaps using statistics if too many shell pixels would need to be traversed, thus setting an upper bound on the shaders per pixel runtime. This would basically be like converting each shell pixel into a box between two shell layers. I imagine this being similar to a parallax shader with multiple layers. It does still have some artefacts unless the statistical guess is good. It would however eliminate the overdraw issue and may reduce the amount of artefacts when looking at it from the side. The per grass blade lighting code could then aslo be more complex, although that has other difficulties since each "ray" diesnt know about neighbor grass blades, since it is guaranteed to happen only once per fragment (each fragment will sample the random function multiple times however, but that shouldnt be as big of an issue, since it doesnt even take fommunication between Threads or bandeidth to read from a texture. Anyways, Im curious what we'll see in the follow up video.

[@JMW1906]

Edit: dynamically changing it by applying displacement would be more difficult and would have more performance overhead however, since that will require some per she'll pixel math Evaluation (or to be more precise: integration into the code for finding the next she'll pixel) as just displacing the shells would not be possible.

[@q_druid7801]

18:54 OH MY GOD! I kept wondering how they made this short soft grass in Genshin, which I really like. Thanks for the video, now I know it

[@Lars22]

It’s a bit after my bedtime but I had to watch this now ;) Could the rendering discussed at the end be helped by logarithmic search? So checking the mid layer first and then closing in recursively?

[@Acerola_t]

That sounds like an interesting optimization, but you'd have to mess around with the ordering of the draw calls manually.

[@Xaymar]

AFAIK, there is one way to "fix" the gap between shells by slightly turning the surface towards the camera in the vertex shader. This allows a camera to be parallel to the shell planes, but the math is so complex i never got it to work right. A different technique that i also know of is parallax hair/grass, but that requires an unholy amount of preprocessing so that you can render curves in depth.

[@miketheburns]

it took me until 22:18 to realize you were layering your shirts throughout the video. Mad props.

[@aidennwitz]

I've always liked gaps in shell textures, I think they look neat

[@iassongionis5473]

NEW ACEROLA BABE WAKE UP 🗣️🗣️

[@iassongionis5473]

+first

[@andvaribekho]

Fantastic video again. Thanks Acerola! I didn't know this technique and loved it. I'm definitely going to use it in my next projects. I'm wondering if overdraw is reduced if PNG8 textures are used? to avoid semi transparent alpha?

[@0brn0]

Excellent as always @Acerola_t. I'm guessing there's a presentation on Z-priming / Pre-Pass techniques on the horizon to counter some of the overdraw/fill-rate costs?

[@ethancory6127]

Saying average person, and then showing Jerma is a war crime

[@clonkex]

WTF, I never realised that's how traditional fur rendering worked!! That's so smart, and also explains the strange stepped look it always has.

[@orthodynamicstereonails]

This is the first of your videos that i could mostly understand virtually every step that we took! im actually really excited for this because you're helping me get a hang of graphics programming while i have zero programming experience, and also shows that your videos are getting better!

[@toonlien4589]

19:33 clever choice of music

[@DracoTheBlack]

Brave of you to assume that I've only watched four videos about rendering grass.

[@Mcbuzzerr]

This video and the Acerola Furry Challenge is great, I love promoting learning!

[@cynthius6567]

I've always been fascinated with how good Fox's fur looked in Star Fox Adventures, considering it was running on the Gamecube. Such a simple trick, but it works wonders, and I think the part that impresses me most is not just how impressive the fur and its "physics" looked, but how well it smoothed out Fox's model and made him look higher fidelity than anything you'd see in other games of the era simply because the fur hid the hard edges of the polygons he was made of.

[@kayasia8916]

Great video! Randomly found this vod while bored and surfing, I really enjoyed all of it!

[@Roxor128]

I figured out that Star Fox Adventures was using this technique back in my university days when I borrowed a friend's Gamecube for a weekend. Also, don't be surprised if your Furry Challenge gets a lot of entries involving characters from that franchise.

[@stevethepocket]

Honestly it's amazing that this isn't more well known among that franchise's fans, or used on fan-made models. I seem to remember reading that the actual models from that game only recently finally got ripped and released to the public-and even then I've only seen them rendered without the shells or even the subtle sheen on Fox's snout-so Rare must have done a really good job obfuscating their file structure. Because it sure wasn't for lack of demand.

[@MrNyagasu]

I'm just going to take a picture of my dog, put it on a simple square mesh and call it a day.

[@parmesanzero7678]

Your explanations are so thorough and have just enough balance of the technical and non-technical to be interesting and educational even to those with no expertise. You’re an excellent teacher.

[@stevethepocket]

Hey, I've been thinking about this some more lately, and I've come up with a simple way this could be further optimized: by having the number of shells vary depending on angle from the camera. The more the "strand" points toward the camera, the fewer it needs to be convincing. Though if you're planning to simulate AO, you'll still need a few at minimum to pull off that effect-and on that note, the tapering effect will also be slightly more work because you'll need to go based on distance from the solid surface rather than shell count. It also wouldn't work for most grass applications since a low camera would suddenly cause almost ALL the grass on screen to need more shells, but for something like Sif or the _Genshin Impact_ moss where it wraps around a round object, it might be ideal.

[@Jomity]

Wouldn't it be possible to billboard the quads towards the camera? That way, there's never a gap between the layers (might ruin the narrowing though)

[@emortal]

Could you do shell rendering with billboarding? That might solve the illusion breaking at an angle. (though if big game studios haven't done it I assume this just isn't useful)

[@stevethepocket]

Exactly my thought as well. It's such an obvious solution that there must be a serious downside. Upvoting in the hopes that people who know stuff see this and respond.

[@ashwanishahrawat4607]

Yeah, This is the first thought of every person who knows Billboarding, problem being that the Billboarding is done to a Quad or Triangle during Vertex Shader phase. but the shell here is made up of rasterized pixels, and Pixel itself is just a dot facing screen already. So doing Shell Texturing of a Quad made up of two triangles, has nothing to further Billboarding.

[@theorybox3094]

Putting a video of your pet during the length of the sponsorship might be the most brilliant move i've ever seen on youtube

[@TimRobertsSound]

Great video. Good to see you adding shells (shirts) as you go.

[@blackasthesky]

I just LOVE the humor in your videos. There is so much there hidden in plain sight. And it isn't even distracting (when you aren't currently writing a comment about it).

[@oby1]

i really would love to see how you would tackle hair strand rendering, like in Ratchet and Clank Rift Apart

[@Acerola_t]

streets are saying rift apart uses shell texturing

[@Big.Joe.Grizzly]

Nice video man ur a clever dude lol you should do a video about reflections in games. Like window reflections, glass, water, floors etc etc.. it's quite interesting to see all the different ways games achieve reflections. My fav example is in MGS1 for ps1 where puddles on the floor are actually just holes in the geometry with a replica map underneath flipped upside down. Such a simple way to do it but it's so effective especially for the time

[@Sylkis89]

I wonder how to make photorealistic mohair/suri alpaca/dual fleece wool/longwol/etc. sweaters, very fluffy but with still distinctly visible structure of the knit that will form various complex patterns, and also how it behaves on a body depending on how tight or loose, the body type, the position the person is taking - how the knit will fold or stretch in different places, and also how the fluffy halo will interact with the lighting, etc... especially if animated, how to make it realistic. Also how to account for the varying thickness of the knit on the body and so on. There's just so much to consider and it seems so difficult and also that usual tricks used for hair will help, but will not cover all bases...

[@held2053]

Tbh, I almost forgot, that the video was about hair, when he talked about the grass field I was invested in it

[@LinuxBacon]

Thanks for adorable cat clips during the sponsor spot

[@karl6980]

I remember trying out using kuwahara filtering in conjunction with shell texturing for grass once, and I remember it looking kind of interesting. Definitely hid the gaps between shells quite a bit

[@dowairu]

This is amazing! I'm just learning about shader programming and finding your videos super interesting. Is there any chance this can be done in Shadertoy? I'm assuming it might be easier with Unity because you can control parameters in the engine?

[@giobrando6574]

the cat video on the ad segment is pure genius ngl I sat through all that

[@rmt3589]

That's amazing, and I plan on making this an innate tool in my engine, as I'll use it a lot! Subscribed btw. At the beginning of the video I was trying to figure out a solution. The one I came up with was to have basic 3d meshes, then use uv textures to make them look deeper, like hair. Either that or transparency. But this is better than either!

[@JKTCGMV13]

I love that you ended with a challenge and I love how you presented it

[@dreamerchrysalis384]

Seriously having the JUNES theme for your ad is just perfect. Oh and the video was very fun to watch too ;)

[@markm1514]

Thanks for the insightful video on fur rendering. The details about shell texturing in shaders were highly valuable, and your video's setup and pacing were spot on. I'm halfway through and I can already tell I'm going to watch it a few times. I'm excited to try this.

[@hootiehoo3000]

Monogatari-styled editing + persona 3 music at the beginning of the video blew my mind

[@Luka9S9]

I've been looking forward to this video for a while, thank you for making a video about shell texturing Acerola, that has been a graphical technique i've aways been curious to see how it is made, It aways felt like there's not a lot of stuff that can easily get you into knowing about shell rendering, this video will be great for that, thank you once again ^^

[@DKarkarov]

Lol the parish teleport was on point, her "what is happening" face was top tier.

[@KingBobXVI]

Waiting the whole video to see if you'd mention Shadow of the Colossus, and it being mentioned at 25:49... RIP in pepperonis, sweet prince. Definitely one of the best looking uses of shell texturing for large creatures, imo, and done with very little processing power at its disposal.

[@mantacid1221]

What if you project the texture of the layer above from the camera position onto the layer below to create an occlusion mask? Would that prevent overdraw?

[@NarwalHorns]

19:34 Acerola: "layer cake" OST playing: Person 5 - Layer Cake 👏

[@skave7228]

I love the visual identity of Shell Texturing ! I'm looking for the know of the technic behind Genshin's moss, so thanks !

[@DracoGalboy]

Very nice job with your own shell layering

[@JACKHARRINGTON]

22:31 The inner workings of Acerola's mind are an enigma. I want to know more.

[@kaneymon]

Another brilliant addition to the acerola grass playlist, thank you. More please.

[@TrueKinth]

Great video. A potentially interesting idea for a future video is to look at how hair is done for humans, which is usually via the hair cards technique.

[@okunamayanad]

i remember watching the stream it was at 17:25 :D idk how acerola always does this but every video of him is interesting

[@tiagolourenco51]

QUESTION : I've been practicing creating shaders and custom post-processing effects in Unity. Recently, I started a project to recreate the shaders used for characters in Genshin Impact. While I feel comfortable working with shaders, I find myself getting stuck when it comes to using RTHandles, render textures, and render features in URP. My question is, what do you recommend for someone who is just starting out in technical art? Should I use the URP Scriptable Render Pipeline, or should I stick with the Built-In Render Pipeline and attach scripts directly to the camera for custom effects?

[@shadowdemonaer]

2:28 generally there would just be a ton of instancing going on for grass and other repeating objects. Instancing is taking and object and duplicating it in such a way that the program acts like there is no extra faces on screen to compute. For example, a cube has 6 sides, and when you duplicate normally you would then have 12 faces to compute, but with instancing you still only have 6. so you can do that with millions of grass blades and have really nice optimization. I'm further in now and really fascinated by how these ideas came to be. Can't wait to see how physics works. Dude I had no idea Genshin did it too. I'm probably going to unfortunately have to figure this out myself.

[@kellerwhite9299]

I would just like to say I appreciated the bit about adding clothing layers (or shells, if you will) throughout the video. That is all, thank you for the quality video and have a nice day. :)

[@KaiHydra]

I wonder if this can be used for generating foilage using generated meshes, this is something i really have wanted to do because I hate the idea of creating individual objects/prefabs for bushes/hedges

[@EdenNeedsAYoutubeHandle]

Shadow of the Colossus was what made me interested in shell texturing long before I even knew there was a name for it. Makes sense that they'd want to draw your eye to it, since fur patches are key to climbing the colossi and all that. It blew me away in 2005 and it still holds up today.

[@fuchsi_arzeus]

i love how he uses his cat to keep us watching during the ad break

[@user-tw2kr6hg4r]

You should probably use acceleration instead of velocity to calculate the displacement or ideally a blend of both after applying a low-pass IIR filter.

[@quincygaming9529]

Getting every achievement in Viva Piñata is no joke. I remember using spreadsheets for that game I found online

[@Acerola_t]

I had the strategy guide lol

[@franciscosuarez4521]

If anyone is interested in how to do human hair, most high fidelity games do "hair cards", It's similar to this, but more handcrafted. You can search that term to find tutorials It's a transparent texture with many rectangular hair parts (the "cards"), each with different densities. Then you model hair strips with long rows of quads, and assign their uv's to one of the cards. The more you stack one above the other, the more real it looks, the same principle as shown in this video. You just use a normal transparent material to display it. It's pretty hard to model I think, even with specialized tools. From what I know you should sculpt it first, use that for generating the strips, and then do manual touch ups High budget modern games do other more realistic approaches probably, share if you know

[@wwyvern418]

You know what's also fun is the cat from Stray uses shell texturing, a very modern case! interesting it still gets use