What is IOR Level? An Introduction to this Principled BSDF value.

[@andreheynes4646]

The realism in those shots in the beginning of the video is nuts. If you offered some courses I would buy it. Your teaching of blender is the best I've seen

[@swannlecocq6083]

Great Tip : Connecting roughness maps to IOR level will boost the reflections and make your materials more alive ! I use this on every shader now

[@RustyNova]

I'd like to add that noise textures are often enough to do the job. No need to go fetch some noise images for everything

[@swannlecocq6083]

@@RustyNova Of course, noise texture is better for noise. I am refering about proper PBR roughness maps that you can plug into the roughness socket AND IOR level to enhance the reflectivity of the whole PBR texture. 💥

[@kes099]

If your map is a proper PBR roughness map then you should probably be inverting it before plugging into IOR Level - lower roughness values equate to higher IOR, higher roughness values equate to lower IOR. Of course, leaving the map uninverted could give you the artistic look you are going for.

[@swannlecocq6083]

@@kes099I Will try that !

[@StudioHoekhuis]

Thanks for this, it maybe not that technical, but demystifies what IOR does in Blender. BTW. This is one of the best Blender channels on KZbin 🔥

[@sleepCircle]

really it's gotta be up there, without exaggeration. it is clear and extremely easy to understand but also not really a "beginner channel," even though it has 'tutorials for beginners' they are astonishingly in-depth and teach me things I didn't even think of doing, and I've been working in blender since 2005

[@diegopadovani4942]

Your channel is my favourite at the moment. After years using Blender, I enjoy a lot your more in depth and advanced stuff videos.

[@fsalad]

Thanks for making these fundamental and crucial stuff approachable

[@Rumble1981]

Another great video! Thanks so much for sharing.

[@3TQHAJSHNQ]

PERFECT TIMING! I needed this.

[@golemtabak1183]

Thank you very much! Your explanations are really important and help me a lot in my general understanding of Blender's way of working.

[@lilneoman1]

A great explanation, I saw your first video but watching this one through helps me understand the former more

[@farhadkhosravi4630]

Thank you Prof. Tyler, that was very informative.

[@felipebaul1119]

Great depth in this video as usual. Thx !

[@kes099]

Thank you for this tutorial Christopher! I think I have used the IOR Level a few times, but on the whole I feel like Blender should not have included it in the Principled BSDF node... if it is true that it simply adjusts the IOR setting under the hood (IOR Level 0 = override IOR setting it to a value of 1 dead matte with no reflections, IOR Level 0.5 = use the current IOR value, IOR Level 1 = override IOR setting it to a value of current IOR x 2?? not sure! are we told anywhere in the documentation?). It's kinda like having two sliders that do the same job. If I had a greyscale map to drive specularity, then instead of plugging it into IOR Level, I could simply plug it into a Map Range node and set the To Min and To Max values to the desired IOR range (eg. To Min 1.3 - To Max 1.55) and then plug that into IOR. Not only that... I download a lot of freebie models from places like Sketchfab and when I import these models into Blender as OBJs or FBXs the materials almost always get set up with IOR Level 0 rather than the default 0.5!! very annoying, as I have to go through every single material and open up the Specular drop down to check the IOR Level... I usually end up deleting the BSDF and adding a fresh one which I know will have default settings everywhere.

[@gatis.pastars]

Very helpfull! Thanks!

[@Aaws424]

What i understand is the IOR controls in what angle your light will reflect And the IOR level controls the intensity of that same reflection !

[@christopher3d475]

The IOR controls the expression of the fresnel curve, which controls the degree of reflectivity at a given angle of incidence. The IOR Level is a scalar function that alters the IOR which then drives the fresnel curve. So you're kind of right.

[@rampally07]

Hi Sir can you make a video on Render quality ...as good as you render images r in yours videos???Thank you for your Great Effort

[@endlessexpanse]

What is this debug dropdown in 5:33? Is it from an addon? What is it for?

[@christopher3d475]

I hadn't noticed it. I realized after recording that I used a build of 4.3 and the debug was some render parameters I guess used for testing some internal updates to Cycles.

[@virtuviewstudio]

Awesome as aways! Can you make a video about metallic/anisotropic shaders?

[@christopher3d475]

If you search my channel, I've already done two videos on anisotropic metals. Those should work for you.

[@virtuviewstudio]

@@christopher3d475 Thanks!

[@L30nHbl]

thanks man!

[@stalkershano]

🎉

[@RomboutVersluijs]

It would be even easier if they did not use a normalized input. Because people find ior values on the web, yet now it goes into a slider. It doesnt behave the same as putting 8j say 1.5 as a base

[@RomboutVersluijs]

I'm talking about the slider or oor level on the specular component. If find this second value a bit confusing

[@Arjjacks]

@@RomboutVersluijs You don't actually need to touch it if you don't want to. It's entirely optional and purely for anyone who wants to artistically tweak their specular reflections. For inputting scientifically accurate IOR values sourced online, plug them into the first IOR field at the top of the Principled BSDF node, where the default value is 1.5. Doing that is more than enough to give you accurate specular reflections. The second value is not necessary and shouldn't be touched if you don't intend to stray from scientific accuracy in your materials.

[@christopher3d475]

Yes, this is true. In fact, as far as scientific accuracy goes, Blender 4.3 is introducing a new Metallic BSDF node (obviously for metals) that allows for the use of N+K measured values per RGB channel.

[@RomboutVersluijs]

@@christopher3d475 but why than per rgb channel, you mean you can set separate n+k for red, green, blue. Why make it difficult again?!? 8 came from Thea Render. That's a full spectral rendered, with all this options already a alable and a couple more. It simple has no presets or you can enter an n and k calue. I don't understand why it needs to be per RGB channel. Perhaps I understood it wrongly though

[@christopher3d475]

@@RomboutVersluijs Because to get a physically correct color for the metal, you need a separate N+K value for the wavelength associated with each R-G-B channel.

[@thegameplay3859]

Can you make full blender course (step by step videos then make playlist) where you explain every thing in blender with live use in video. Then you can sell that course on udemy or other website for money. But keep free on youtube. In HOLY Books said. If you will give free any thing GOD of jesus will give you 10 times more. Like you will give 100$ you will get 1000$ back from God of Jesus. Like wise if you will give free information (blender videos) then you will get 10 times more information free. Hope you will make blender full course as soon as possible to cover every thing in blender. THANKS.