3D Basics - What are Normals?

Face normals? Vertex normals? Flipped normals? Learn all about normals in this tutorial on 3D basics. This is another lecture from our course The Blender Encyclopedia, check it out here - cgmasters.com/the-blender-enc...
Resource files for this tutorial are available in the full course on Udemy.
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[@myahgloom4717]

I can’t believe how clear normals were explained. Honestly the best explanation I’ve found on the internet and I’ve done my research!

[@blengine]

Thanks guys! I know there's quite a few tutorials out there on this already, but I thought my take on simplifying things could help those left a little unclear still. So I'm happy to hear this =) -Chris

[@CoRon3x]

Took me 3 tutorials from 3 different people to finally land here and get a clear explanation that doesn't raise even more questions. Thank you!

[@blengine]

Happy to hear it!

[@Bax365]

9:29 Perfect definition right here. Easy to understand and to the point.

[@joelpaik]

Thank you so much for this! Normals are tragically underdocumented in blender for beginners and so many of the problems I ran into as a beginner came from normal issues. I would have loved something like this back in 2014!

[@SpoonerStudios]

Best tutorial on normals I have ever been able to understand. Thanks for this, explains so much.

[@macronchampion]

Ok I'll buy you course right now, I finally understand what is a normal

[@Eridian757]

Easily a great tutorial for art , understanding light to surface interactions is so clearly and concisely explained here . Thank you man .

[@scholzdigital]

Man, this was so helpful! Thanks! I will watch all your other stuff as well. Love the teaching style a lot.

[@katethebard]

Really appreciate this awesome content! Very well-constructed introduction to normals. Thank y'all!

[@andypuempel2570]

Very Clear and systematic presentation. Nicely done. Excellent instructional technique.

[@aninekruger4721]

Best explanation ever!! Thank you sooooo much!!

[@aminjl_art]

simple to the point, loved it

[@gaburieruR]

É, parece que as aulas de física deram frutos! Normais em física e modelagem 3D são ideias parecidas! Muito obrigado pelo tutorial, muito explicativo!

[@_i_m_]

Very useful video, thanks!

[@josephvanwyk2088]

Well this was a FREAKIN IMPORTANT video to watch. Well done. Thanks.

[@DGaryGrady]

From my math background I already had a theoretical understanding of normals and the relationship of normals to shading, including flat versus smooth shading, but I still found this very informative and worth watching all the way through. I agree completely with Myah Gloom (great name by the way!), Spooner Studios, RealTimeX, et al that this is a brilliant tutorial.

[@blengine]

I thought of including some math in this for a deeper understanding, but after making the initial outline it just seemed like it would complicate it for people newer to the subject. And it's awesome to hear someone with a math background still found the simplified explanations interesting, thanks for the compliments! -Chris

[@DGaryGrady]

@@blengine I think what your decision was exactly right, and besides the modern mathematical approach tends to emphasize abstractions anyway -- vectors and tensors as entities distinct from their numerical representations, for example. By the way, here's an early paper from Ed Catmull (way before Pixar) that's not exactly packed with equations either: ohiostate.pressbooks.pub/app/uploads/sites/45/2017/09/catmull-movies.pdf Note that the commands for animating a human hand were entered in the form of text on a Teletype! Anyone who thought that pre-2.5 versions of Blender had a difficult interface needs to think about this! Also, to produce a movie they had to photograph a CRT screen with a film camera. In fact, even ILM's early CGI work had to do this, and they had to adjust the camera's shutter angle to allow for the gradual change in brightness of CRT phosphors. (I used to know some people who worked there.) We don't know how easy we have it now.

[@blengine]

​@@DGaryGrady Ah it's refreshing seeing a more technical paper break things down on that level. And wow, they were a different breed of creatives back then haha, these methods require some serious dedication in contrast to what we can achieve now with just a few clicks.

[@NyanCatTheOnlyOne]

Thanks, this was extremely useful. I kept hearing about flip normales without knowing what that mean!

[@dropletdew5429]

Thank you so much for explaining this! Us Blender beginners really value this info in our way to learn how to use the software.

[@gauravnegi6857]

this video pushed me to buy the course, and so far it's quite amazing.

[@blengine]

Thank you I'm glad you like it! The course is getting quite old at this point, but I still think there's a lot of worthwhile stuff in there.

[@gauravnegi6857]

​@@blenginethat's no problem honestly. I came here cause I reached the normal video In that course too after watching it on youtube.😅 The course was designed quite a lot the way I like a course to be. I can see some stuff being old, but I am still learning a lot. Thanks a lot for making it, when you reach projects and you have an idea of what tools does what it makes it a lot more engaging.

[@MikhailCazi]

This was so precisely done.

[@ygypt]

3d stuff is always the most confusing and time consuming in my projects. you explain things so well for idiots like me thx so much bb

[@samratix2497]

OMG thanks sir. Your teaching capacity is awesome. I was confused about normal even after watching several videos until I saw yours.

[@blengine]

Thanks, happy to help!

[@SkSafowan]

Great video keep those coming !

[@NB-qj5ol]

Good explanation thanks

[@bang3412]

Thank you very much!

[@harsh8457]

Subscribed for great teaching I want in future :)

[@sdrawkcabdaernacuoy]

Great tutorial, as normal.

[@gravijah]

Wow so many things that make now sense, thx!!

[@cubbleshasreturned6968]

This is so clear and concise! You don't know how stressed I was trying to figure this out!

[@blengine]

Glad you liked it! For some reason it seems like this is one of the most over-complicated topics in 3D.

[@cubbleshasreturned6968]

​@@blenginewill there be a part 2 coming soon?

[@blengine]

​@@cubbleshasreturned6968 I think this one covered everything I set out to cover, but is there some specific info you'd like to see in a part 2?

[@taimurcgi]

Extremely underrated!

[@rmt3589]

The internet will likely have to deal with me continuously asking what normals are for the foreseeable future. Edit: This video actually taught me a lot. I keep forgetting what normals are and having to reresearch them, so hopefully it sticks this time.

[@tahwissa]

Top tutorial

[@ksenijapopovic9619]

So good

[@techofhappiness395]

Really great Tutorial 😊 and well explained. Please make videos on other Maps also.

[@blengine]

This is something I'm anxious to get to, just explaining all the different types of texture maps, so maybe I'll start on this soon. -Chris

[@techofhappiness395]

@@blengineMany Thanks

[@fallandrix5232]

Been searching for a definition of Surface Normal because I'm now on my Fresnel Effect lesson of my Shading Course in Fine Arts.... AND FOR ALL VISUAL ARTISTS OUT THERE! SURFACE NORMAL IS JUST A FANCY WORD FOR THE DIRECTION OF THE PLANE! LIKE WHAT THE F! btw... great vid! love ya bruh..

[@blengine]

Yep I went far too long thinking normals were way more complicated than they are. Hope this video clears things up for a lot of people that thought the same =)

[@cervidae3359]

It's a lot easier to see the normals if you check the "face orientation" box in viewport overlays.

[@blengine]

Yeah that's true I should have included that in the second half of the video, but the lines were necessary to visualize the angles involved. -Chris

[@jparmy6803]

Alternatively turn on backface culling in the viewport shading drop down

[@ronaldhulsmeyer1052]

Thank you. Very clear descriptions. I would be interested in purchasing your course but I need to know if your course is updated to the 4.1 version seeing as how you are using 2.8 on the purchase page. That's where I ran into trouble with my last course. 4.1 works a whole lot differently than what they were teaching me on and that caused nothing but problems. Please let me know. Thanks again

[@blengine]

Unfortunately this is the nature of Blender these days. There's a ton of tutorials, and only a handful are 100% compatible with the latest Blender version at any given time. The Blender Encyclopedia is no longer being updated because the funding just isn't there to keep up with that course, and at this point an update would basically mean an entirely new course. There is a lot of information in that course that's compatible with the latest Blender, but there will be many incompatible parts along the way, so I wouldn't recommend that course if you're looking for something more straightforward to follow, sorry about that. I would love to redo this course, making it even bigger as well, but with the way Blender is updated and tutorials are outdated, including by irrational changes to tool names and UI shuffling, I no longer think I'll be making another course like this.

[@ronaldhulsmeyer1052]

@@blengine Okay, thank you. Sorry to hear that. I'm fairly new to this and it's just frustrating searching through a million videos to find a simple 2 click solution to a problem. I'd be willing to pay someone with knowledge just to be able to ask them questions when running into snags without having to search through their vast array of courses to find what I missed or ask a Blender community that doesn't really help either. I'm still struggling with simple, basics that I can't find answers to. Again, I'd pay someone just to point me in the right direction when I'm stuck. You give great, detailed advice. Sorry you won't be making more courses. Thanks for the reply, friend. Ron

[@blengine]

@@ronaldhulsmeyer1052 I'll definitely be making more courses, just not one that's like the Encyclopedia course, though I may release tutorials similar to that on KZbin. If you're looking for some personal training, I unfortunately don't really know where to look. You could try posting in the forums at blenderartists.org though, and hopefully you can find some help.

[@JohnDaniels]

Hello, I am talking with a developer from Nvidia's PhysX division and he said the following. Does this sound like he means the normal on the static mesh and if so how would you project the normal onto a analytical cylindrical surface? "There are solutions available. The first option would be to leverage contact modification - you can just take those contact points, project them onto an analytical cylindrical surface and adjust the normal to point back to the COM of the shape. If you do this, you'll get perfectly smooth contacts."

[@blengine]

Hey John, I really have no idea what any of that means.

[@JohnDaniels]

@@blengine That makes 2 of us 😁Thank you for the reply 👍🏻

[@MIchaelSybi]

As far as I understand, normals are a simplification of how real life surfaces work. What you've described is similar to diffuse shading model. As the angle of the lightsource changes from perpendicular to paralel, the amount of light decreases that hits the surface, hence the surface becomes less bright. Lambert's Cosine Law might shed some light on it to reflect upon. Imagine you look from the light point of view, and when you view the surface form the 45 degree angle, you see less of its surface, and it decreases the more you get towards the parralel angle of light rays fo the surface

[@blengine]

Normals themselves are simply the direction a face or vertex is pointing, and that's all. They're nothing more complex than that. They are indeed used for calculating shading, but also used for certain tools like extrusion, and for different modifier operations. But normals themselves are just the direction something is pointing.

[@MIchaelSybi]

@@blengine Of course. I was referring to light incidence decay related to normal

[@blengine]

​@@MIchaelSybi Okay just making sure =) Because normals are probably the most needlessly overcomplicated subject in 3D, and I wanted to make sure anyone reading the comments understands that normals themselves are not complicated.

[@MIchaelSybi]

@@blengine And I very, very thank you for this! You did a great job at it. Explaining something in simple terms is an art of itself

[@blengine]

@@MIchaelSybi Thank you very much!

[@anghaiphung6243]

Hi Chris, you say that Flat shading uses face normals to light the surface, but if I rotate a vertex's normal in Flat shading mode, the shading of that face looks off while its face normal still points upward. Can you shed some light on this?

[@blengine]

Rotating or modifying normals creates a set of "Custom Normals" or "Split Normals" which is a bit of a different story. I go over more about that in the "Editing Normals" lecture in the course. I'm sure there is some information on those topics on youtube as well, but I don't personally have anything on my channel about that right now. -Chris

[@aravindsreekumar7022]

Great tutorials man.. i have some problems while doing a model I recalculated the normals, but when i try to move the vertices snapping to any of the axes, the movement is not alligned with the Reference plane. what to do with that??

[@blengine]

I don't think I understand the scenario. Could to share an image of the issue?

[@aravindsreekumar7022]

@@blengine it got cleared. Thank you 😌😊😊

[@ksenijapopovic9619]

Could you go a bit more into normals and particles?

[@blengine]

Particles aren't something I use much, but if I ever do I'm sure I'll have some more tutorials on it, and I'll keep the request in mind.

[@gab910]

please can u tell me how to put normals in both in and out of the face?

[@blengine]

Hey, I'm not really sure what you're asking, can you give me an example of what you're trying to accomplish?

[@gab910]

@@blengine i exported a leaf to unity and it shows one side that's why i need to put the normals on both back and front 😅

[@blengine]

​@@gab910 Every face basically has normals for each side, normals are just the direction a face is pointing, and this direction is used for shading both sides of a face. However, in game engines, it's typical to only render one side of a face by default, for optimization purposes, because you often don't see both sides of a face. So the game engine only renders faces pointing outward, and makes the inward faces(also called back-faces) invisible using a feature called Back-Face Culling. There is likely some kind of option in Unity to turn back-face culling off for individual objects. This might be listed as "back-face culling", which you would turn off for a leaf, or it might be something like "double-sided", which you would turn on for the leaf. Where this is, I don't know, I haven't used Unity so you'll have to fish around for that.

[@gab910]

@@blengine Thank you for the explanation

[@captaincrispy2184]

Two people have to recalculate their like.

[@TechnicalJatin1]

Chris , Pls Make a Course on one more car modelling but this time more advance like Buggati gran turismo. i would definitely buy it whatever price it have 😩🧡 please make

[@blengine]

I am 100% making another car course, but I have no idea when, I'm *still* catching my breath from the corvette course. I also don't know what car I'll be modeling either, lots of good ones to consider!

[@TechnicalJatin1]

@@blengine HeHe Making This Encyclopedia Course is Easy Than The Corvette I Guess !?

[@onurerbay7672]

www.the-blueprints.com/blueprints/cars/bugatti/83291/view/bugatti_vision_gran_turismo/ here are the blueprints :) You can try to model it on your own without a course. That's what I will try as soon as I am finished with Chris' Corvette. But I totally agree, I would definitely buy another car course made by Chris.

[@onurerbay7672]

@RealTimeX I have not searched for architectural blueprints yet. Here is another good resource for vehicles and aircrafts: drawingdatabase.com/category/vehicles/cars/

[@blengine]

@@TechnicalJatin1 Yeah definitely. Though the encyclopedia actually took around 15 months, and the corvette course around 6 months. The difference is that with the encyclopedia I was working on tons and tons of different topics, so it was always new and interesting. With the corvette course, I probably modeled that corvette about 7 times over and over during that 6 months to get the recording right, so it just got super tedious and draining.

[@yagz7820]

So same normals with mathematics

[@0815Snickersboy]

Here is a comment for the algorithm ;)

[@bhavinb.artstation]

It's normal to think tht normals are easy to understand

[@ZorlacSkater]

But why did they named it "normals" and not "perpendiculars" or "surface vectors" or something similar, that would make much more sense.

[@blengine]

Heh, yeah I don't know what the origins of the word normal are in geometry, but I agree, a more specific term for it would be nice.

[@Ardeact]

how many CG artists know this? I sounds so crucial yet not talked about

[@blengine]

I'll be honest, I didn't even fully understand the topic for like a decade. I mean I knew what I needed to know, but it always had a slight amount of mystery surrounding it. Then after I decided to really figure it all out I was surprised at how simple it truly is and how over-complicated others make it seem.

[@sabmis2658]

Vertex normals makes no sense to me, they are just dots...

[@blengine]

True, a 1-dimensional point has no direction so it wouldn't have a normal, but in Blender they're not just 1d points, they can also be used to store other information. Like in this case, you can look at it like the vertex not having its own direction, but rather it's representing the directions of the surrounding faces and edges.

[@aqualust5016]

The term normals needs to be revised with something more intuitive by the pros and experts in these industries. It’s an absolute waste of time trying to understand jargon that is too obscure for others to grasp without a deep explanation. Face direction, face surface, or mesh orientation would be fine.

[@blengine]

I would've been happy if it was just less of a common everyday word and a word all its own.

[@artur2945]

Учите тригонометрию, математику по лучше и не будете такими тупыми..жесть ка для детей рассказывает

[@DGaryGrady]

Artur: That's a little harsh, and I'd hate for math phobias to discourage people from using Blender. Sure, it helps to understand the underlying theory (and besides trigonometry I'd include vector analysis and basic optics, by the way), but lots of Blender artists do great work with only a vague understanding of what's going on underneath. Also, working with Blender is a good way to learn the theory,

[@blengine]

Артур Саптаров, you're right. In fact when we toggle "show normals" it should pop up with a math equation on each face instead of a blue line. That would be so much more clear, stupid Blender!... Math isn't necessary *at all* for introducing normals and their practical purposes. -Chris