Silverwing Quickish-Tip: Understanding BxDFs

Made Using C4D 2023.2.1
Octane 2022.1.1 R5

This week its a rather technical topic of the "Understanding ..." series.
Hopefully you like this approach and learn something from this!

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00:00 Intro
00:24 What are BxDFs
04:03 Where to find BxDFs in Octane and Benefits
04:56 Mictofacet Model: Mirror like Reflections
06:13 Mictofacet Model: Raough Surface
07:46 Mictofacet Model: Ray Distribution
09:54 Reflection Diagram: Beckmann
10:16 Reflection Diagram: Explanation In C4D
11:27 Reflection Diagram: GGX
12:14 GGX Real World Example
14:17 Hands On: 3D Scene Refl. Roughness
14:52 Hands On: Octane BxDF Roughness Scale
15:46 Hands On: Octane BxDF Max Roughness
16:27 Hands On: Octane BxDF Anisotropy
16:27 Hands On: Octane BxDF Anisotropy
17:17 Hands On: Quick Look at Standard Surface
16:27 Hands On: Fringe Cases Frosted Glass
19:31 Hands On: Fringe Cases STD BxDF
22:13 Reflection Diagram: Comparing BxDF Graphs
23:38 Summing Up & Recommendation
24:38 Patreon Shoutout & Outro

[ಥ_ಥ]

You run a criminally-underrated channel. I seldom see educational videos that are this rich with information distilled into such a digestible format. Thank you!

[FreakeSport]

never even thouched the STD model. Thanks for the video, very insightful!

[WillGibbons]

A masterclass in pedagogy! I'm not a C4D user, but am always here to learn from how you teach and pick up any tips that are render engine agnostic. Thanks!

[alokitpathik]

Most awaited tutorial thank you so much

[zotake]

Masterclass! I really needed to understand the differences between the BxDF's. Thank you!

[ThomvanVliet]

I love these deeper subjects. It teaches my WHY I should need or use certain elements which are otherwise simply "different models I'm trying out to see what works"

[bazibada]

Thank you that's so interesting !

[rhinotoday]

Appreciate for your detailed explaination🎉

[ColinCharlesD]

Precious knowledge right here Raphael thank you for all the hard work and for sharing it.

[whitekraw]

It's always great to see a long video, and you "distributed" so much knowledge in this video. Thank you so much!!!

[Jimioc]

This is great, I always picked at random and didn't know what the difference was. The theory behind it is so important and I really appreciate your work

[MrBrainsquash]

Now I understand better why and when. Thanks!

[StijnOrlans]

Love these more theoretical videos! Really takes your work to the next level if you have a fundamental understanding of what's going on behind the scenes in these programs.

[awolism]

Great stuff! Would love a deep dive into fresnel as well!

[NewPlastic]

Well looks like you saved me from making this video. Great stuff as always dude!

[yassinrupp]

what a great tutorial!
+1 for an Advanced IOR Tut.

[vladan.Poison]

Raphael thank you for this..its very tech-y but its who you are. I love you for that ! 2 week ago i got pissed so much on octane that i've decided to shift to RedShift
I am nearly there. watched over 150 hours of top shelf training and i am very excited on the power of RS. Hope you switch to it soon .

[zaidi]

I’m glad to know that the octane brdf hack for frosted glass is approved by an expert! Also I like the smart use of resolve at the end, lot’s of value as usual ✨

[georgeluna]

Awesome, was looking for a long time for this info! what about when using maps for each channel? Does it make any difference if using octane's default or GGX?

[maxtarpini]

It's "Student's t-distribution". More important really.. the bell shaped stuff you posted are probability densities (PDFs) and not 'BSDF' and mainly, the Y axe is not 'reflection strength' by any means... the top of the curve for example represents a mirror reflection probability.. so let's say roughness is zero, the whole curve will be just a straight line pointing to the top (ie. an impulse aka a Dirac).. meaning you don't have any other probability to shot other directions than a mirror one.. then the higher the roughness the fatter the curve .. meaning the range of directions is increased and different directions have some probabilities to kick in.. of course the more directions the less reflection strength because more stuff is sampled (ie. in your examples.. not all directions will sample a light.. producing the visual falloff typical of specular highlights).