Math for Game Developers - Triangle Mesh Normals

Wherein we apply normal vectors to our triangle mesh so that it can be rendered with light and shading.
Find the source code here: github.com/BSVino/MathForGameDevelopers/tree/trimesh-normals
New video every Thursday. Question? Leave a comment below, or ask me on Twitter: VinoBS

[@Cinarbayramic]

thank you man, i really needed this.

[@SinTh0r4s]

Man you are AWESOME! You need one and a half Minutes to explain me, what my professor fail one and a half hours long :P Keep it up! +1

[@sayochikun3288]

very fast and good. I had no idea about this subject and understood everything u explained

[@thejolv]

You just made my day

[@bamsgian9759]

thanks man, you aiding my curiosity

[@martinmazanek3549]

Hi, do you really need when calculating vecAverage to multiply it by 0.5f before normalizing? It should work without it :) Great videos btw. I really love them :)

[@JorgeVinoRodriguez]

Haha good point I guess you dont!

[@DommageCollateral]

ahhhhhhh i think i finalloy learned something here. you generate a normalvector from the triangles vectors in order to project light ontoo the face

[@kevin-hw6er]

thanks

[@7GIGEO7]

Amazing tutorials..!

[@fraserglasgow5735]

THANK YOU!!!

[@NeilRoy]

Or "flat shading" and "smooth shading" (which is what most rendering software will call it).

[@Luixxxd1]

C4D be like: *asian last name*

[@Nick_fb]

This is top stuff. If you wanted to do more, you could do area & angle weighted normals for the alien isolation / star citizen look.

[@duality4y]

w8 is this a series? sounds awesome

[@jRsqILVOY]

How do you choose the tangents for the triangular mesh btw?

[@aL3891_]

Love these videos :) i have a question though, if you use flat shading, two vertices that share a point have different normals, but then how does that work with indexed rendering? Maybe it doesn't? I suppose you could use different indices for the flat shaded faces(so that they don't actually share points) but that seems do defeat the purpose

[@JorgeVinoRodriguez]

Yeah, notice how I didn't show the indexed rendering step for this one. You can still use indexed rendering but your faces won't be sharing verts anymore. Most hi res models these days are smooth shaded though, and creases are handled with normal maps or other tricks like that.

[@undefBehav]

Do you have to calculate the average? Wouldn't it suffice to add all the surface normals together that are shared by the same vertex, and normalize that sum?

[@JorgeVinoRodriguez]

Yes, same thing. Probably I decided to show it this way for pedagogical purposes, or possibly it didn't occur to me that the extra division was unnecessary.

[@undefBehav]

@@JorgeVinoRodriguez Makes sense. Thanks for the clarification!

[@liam6550]

Latecomer here, but there are issues with situations where similar faces that share the vertex will bias the result

[@undefBehav]

@@liam6550 Yeah, but that would also happen if you took their average as well. It's algebraically the same whether you took the average and then normalized it, or normalized them without averaging.

[@liam6550]

@@undefBehav I know what normalizing does. Accounting for the bias that came from similar faces is a problem I've only recently successfully solved using a combination of angle weights and area weights. I was looking for some help on how to fix it here

[@vishnubharathit6192]

"Triangle mesh normals" Can you share refence book here? I want to know more about triangle mesh normal concepts

[@JorgeVinoRodriguez]

***** Try the book 3d Math Primer for Graphics and Game Development by Dunn and Parberry.

[@themeliskalomoiros4368]

@@JorgeVinoRodriguez That's a great book, thank you very much!

[@dionyzus2909]

that was the most ugly lamp I've ever seen! haha thanks for the class! (: