I have been in archviz industry for over 5 years and have never been able to understand what exactly IOR values does. But now I do after watching this 20 min long content. Your explanation is just simple, clear and straightforward. I really appreciate it.
Christopher I always love your tuts so I couldn't break out laughing when you said "Intensity Of Reflections", which could have the same acronym as IOR (Index of Refraction)!
Thanks a lot for these detailed explanations for the changes in Specular component of the new Principled BSDF shader introduced in Blender 4.0.. I would like to see a similar explanation regarding the changes in the subsurface component of the new Principled BSDF..
Just brilliant! Once again, a tutorial packed full of information. Thank you so much for explaining in so much detail. With your help, I now understand a little more. THANK YOU! Dg
Thank you for that video, this is extremely usefull when im not using blender that hard but want to keep up with the new updates and how they work, nicely done!
Thanks for the video. I think I’d lean towards using the IOR Level over editing the IOR as it shows that artistic choices have been made over that being a correct IOR value.
I love your Tutorials, you sound familiar, and the way you teach, as well as the precision you have, makes me wonder, were you a tutor on Digital Tutors around 2014?"
Happy New Year and thank you very much for the tutorial.👍😃. In 10 May 2022, you have an video titled "Specular Reflections & Variable Roughness". Now that the new Principled BSDF fixed the energy conversation issue. To make the floor more reflective at low viewing angle, do I still use the 2 methods mentioned in your video or you have a better method to make the variable roughness materials in Blender 4.0? Thank you for your time and help.😄
Hi Chris, how did you draw the fresnel curves (the formula you used to change the F0 value with IOR) based on changing the IOR value? Any help or link will be useful, I need to present the fresnel curves generated based on IOR value change in Blender. Thanks for the video. Edit: I think I found the answer: F0 = [(ior - outside_ior) / (ior + outside_ior)]^2 where outside_ior will be air, so = 1 and then use this number in Schlik's Fresnel approximation, feel free to correct me
This was a very interesting video, but I am having a hard time figuring out how specular maps fit into this new process. I have specular maps that I have used for many years that no longer work as expected when mapped to an object. It's especially frustrating when I have a texture that previously had an irregular specular; portions had high specularity and portions had very low or almost no specularity. The mapping doesn't appear to affect this any longer. I can see the effects of the map, but now the entire object maintains a constant level of specularity, with the portions mapped to have higher specularity appearing normally, but the portions having low to no specularity still providing specularity, even high enough to provide reflections where previously the texture map did not.
@@christopher3d475 I did some basic tests using a checkerboard specular map and it seemed to work just fine. I've gone back to the texture to see if there might be something off in the roughness mapping - the specular map appears to be correct based on the results I got testing the checkerboard, but I'm still getting high specular in places it shouldn't be where I haven't previously had this issue with this particular texture set. The texture set is smooth concrete with only minor polish in places, so the reflectivity across the entire surface is definitely odd. Thank you for replying!
What does this change do regarding converting assets that were created with a gloss/specular workflow (such as objects originally made for unity)? In previous version of blender, I was told to invert the gloss map and plug it into the roughness input of the principled shader but rarely got a consistent or clear story of what should have been done with a specular map. Do these new changes make this any clearer?
May I ask how on your last scene about tint, the base color is neutral gray but shows black? I set material to your as I was watching to follow along and my neutral gray was just that, gray. How is yours black?
Thank you. It was hard to follow until the end. So now that I got it, the BSDF Node visual setup (how and where are the setting for connected options) is for me not very logical placed. (like most things in blender)
the speed of light is constant. IOR describes time (relative reciprocal of the difference between vacuum and solid) that takes light to pass through the medium. In other words, the difference of travel time defined by the path light took within, not the speed of light in particular.
When I change the "Levels" value, it does absolutely nothing to the render. There is no doubling of the Reflection when I set it to 1, and no decrease of the reflectiona when I set it to 0.25 (with a constant IOR of 1.5). Am I forgetting another value? Otherwise great video- thank you so much! (Edit: I am using 4.0.2)
I’m still confused about this. If changing either IOR and IOR Level will achieve the same effect, why are you able to independently alter both of them? Shouldn’t changing IOR to 1.33 automatically lower IOR Level to .25? What effect would altering both values have?
It's a compound effect. So whatever the IOR value is set to, the IOR Level alters that. So just use one or the other. The IOR Level is really there for backward compatibility, or for people who don't understand the IOR itself and just want a simple scalar value to adjust the reflections. So just use one or the other.
What the ior never adjusted the specilar ior pre 4.0 Than what did it adjust, im totslly baffled. I dont understand why they have separate ior values now. I come from a different engine. And the ior is for specilar or glossy finish. Only if you had coating would it introduce a second ior, but that was for the coating only. Was the ior pre 4.0 only for the metals than? Very weird, i never new this
Until 4.0 came out, the IOR in the Principled BSDF only controlled refraction of transparent objects (it also correctly control reflections for them), but it otherwise didn't do anything. It didn't control specular reflections like most other render engines. So that was definitely confusing for people who were used to the IOR controlling reflections. So they've made the Principled BSDF in 4.0 more consistent with other render engines now.
@@christopher3d475 man now I understand. I also come from different engine. I used These Render, a full spectrum physical correct engine. It has tons of settings in materials which cycles still doesn't have. Was so nice to create materials in there. It is not node based, but layer based. You make materials using base components and stack them. Then use masks to show what component at which spot. I am glad we also get proper coating now. Ps mostly the coating causes that effect on cars. Especially the thickness. Current thickness is hard coded, still not physical correct. But it's getting there
@@christopher3d475 man now I understand. I also come from different engine. I used These Render, a full spectrum physical correct engine. It has tons of settings in materials which cycles still doesn't have. Was so nice to create materials in there. It is not node based, but layer based. You make materials using base components and stack them. Then use masks to show what component at which spot. I am glad we also get proper coating now. Ps mostly the coating causes that effect on cars. Especially the thickness. Current thickness is hard coded, still not physical correct. But it's getting there
Great tutorial, but there is something about your renders that don't look realistic. Clean but they are missing something 🤭. Can you look into it and do an explanation video on how you can take it to realism? Something about the wood on the chair, tiles, towels, the sculpture... (what looks right it's the marble counter and the items on it - the right corner). Also, the rough copper you used on some items looks flat somehow,.., especially that radiator behind the tap above the bathtup)
As if 3d graphics wasn't hard enough for beginners they now have to understand refractive & reflective physics just to do a "fluid in a glass" simulation which, to me takes the "fun" out of 3d graphics. It's a whole lot easier to just put the slider on max & min values & see what looks best & run with it. 🤔
I have been in archviz industry for over 5 years and have never been able to understand what exactly IOR values does. But now I do after watching this 20 min long content. Your explanation is just simple, clear and straightforward. I really appreciate it.
Like always, great video. no annyoing background music - just information, compact and comprehensible. Thanks, your channel a gift.
this channel is a gemstone compared to all the 'content creators' making videos on blender tutorials
No.
crazy free knowledge , you re my new favorite blender youtuber
Now having had this explained, it makes so much more sense. Thank you so much for taking the time to make this video 👍🏻
Your work is pure gold with high IOR level
You are an incredible teacher. Reminding me of my days in Physics I and II. Great job!
Thank you so very much for speaking to us and not down. Thank you also for remaining inclusive. It is a rare treat to discover your channel.
I'll be learning blender (bit tired of Autodesk bs in production) and these videos are huge help.
I'm a new Blender user so videos like this are a great help for demystifying the many features to learn for shading. Thanks for this!
Amazing video as always, a lot of thought went into the presentation!
Christopher I always love your tuts so I couldn't break out laughing when you said "Intensity Of Reflections", which could have the same acronym as IOR (Index of Refraction)!
Thanks a lot for these detailed explanations for the changes in Specular component of the new Principled BSDF shader introduced in Blender 4.0.. I would like to see a similar explanation regarding the changes in the subsurface component of the new Principled BSDF..
I don't know how this channel doesn't have more subscribers and especially after pablo promoted this channel on blender today
Always look forward to an upload from you!
Perfect once again. Seeing things more clear regarding blender materials after this video/
NIce toothbrush. And, of course, the explanation.
This is pure gold, thank you!
Just brilliant! Once again, a tutorial packed full of information. Thank you so much for explaining in so much detail. With your help, I now understand a little more. THANK YOU! Dg
Thank you for that video, this is extremely usefull when im not using blender that hard but want to keep up with the new updates and how they work, nicely done!
Thanks for the video.
I think I’d lean towards using the IOR Level over editing the IOR as it shows that artistic choices have been made over that being a correct IOR value.
Wonderful videos all time
I love your Tutorials, you sound familiar, and the way you teach, as well as the precision you have, makes me wonder, were you a tutor on Digital Tutors around 2014?"
Awesome Video 👍 Thanks For The Information !
Really useful video.
Incidence of Refraction? Awesome! Blender just keeps getting better. Great videos, Christopher 😃
Great content, thank you!
Happy New Year and thank you very much for the tutorial.👍😃. In 10 May 2022, you have an video titled "Specular Reflections & Variable Roughness". Now that the new Principled BSDF fixed the energy conversation issue. To make the floor more reflective at low viewing angle, do I still use the 2 methods mentioned in your video or you have a better method to make the variable roughness materials in Blender 4.0? Thank you for your time and help.😄
No, it works the same in 4.0. So that older video still applies.
@@christopher3d475 , Thank you very much. 👍😃 Have a good day.
Hi Chris, how did you draw the fresnel curves (the formula you used to change the F0 value with IOR) based on changing the IOR value? Any help or link will be useful, I need to present the fresnel curves generated based on IOR value change in Blender. Thanks for the video.
Edit: I think I found the answer: F0 = [(ior - outside_ior) / (ior + outside_ior)]^2 where outside_ior will be air, so = 1 and then use this number in Schlik's Fresnel approximation, feel free to correct me
I kept on putting of watching it because I read it as "What is IOR of 4.0" and I was like huh but then I clicked on it and it all made sense lol.
This was a very interesting video, but I am having a hard time figuring out how specular maps fit into this new process. I have specular maps that I have used for many years that no longer work as expected when mapped to an object. It's especially frustrating when I have a texture that previously had an irregular specular; portions had high specularity and portions had very low or almost no specularity. The mapping doesn't appear to affect this any longer. I can see the effects of the map, but now the entire object maintains a constant level of specularity, with the portions mapped to have higher specularity appearing normally, but the portions having low to no specularity still providing specularity, even high enough to provide reflections where previously the texture map did not.
I would need to see an example file. The way they engineered the IOR Level parameter should match pretty closely to the 3.x behavior.
@@christopher3d475 I did some basic tests using a checkerboard specular map and it seemed to work just fine. I've gone back to the texture to see if there might be something off in the roughness mapping - the specular map appears to be correct based on the results I got testing the checkerboard, but I'm still getting high specular in places it shouldn't be where I haven't previously had this issue with this particular texture set.
The texture set is smooth concrete with only minor polish in places, so the reflectivity across the entire surface is definitely odd.
Thank you for replying!
What does this change do regarding converting assets that were created with a gloss/specular workflow (such as objects originally made for unity)? In previous version of blender, I was told to invert the gloss map and plug it into the roughness input of the principled shader but rarely got a consistent or clear story of what should have been done with a specular map. Do these new changes make this any clearer?
Drive the specular map into IOR level. IOR Level does what 'specular' did in 3.6.
May I ask how on your last scene about tint, the base color is neutral gray but shows black? I set material to your as I was watching to follow along and my neutral gray was just that, gray.
How is yours black?
Thank you. It was hard to follow until the end.
So now that I got it, the BSDF Node visual setup (how and where are the setting for connected options) is for me not very logical placed. (like most things in blender)
nice!
the speed of light is constant. IOR describes time (relative reciprocal of the difference between vacuum and solid) that takes light to pass through the medium. In other words, the difference of travel time defined by the path light took within, not the speed of light in particular.
midwits leave en.wikipedia.org/wiki/Ewald%E2%80%93Oseen_extinction_theorem
When I change the "Levels" value, it does absolutely nothing to the render. There is no doubling of the Reflection when I set it to 1, and no decrease of the reflectiona when I set it to 0.25 (with a constant IOR of 1.5). Am I forgetting another value?
Otherwise great video- thank you so much! (Edit: I am using 4.0.2)
I would need to see the file. Is the material in Metal mode? If that's the case then IOR Levels won't have any effect.
The speed of light is constant.
I’m still confused about this. If changing either IOR and IOR Level will achieve the same effect, why are you able to independently alter both of them? Shouldn’t changing IOR to 1.33 automatically lower IOR Level to .25? What effect would altering both values have?
It's a compound effect. So whatever the IOR value is set to, the IOR Level alters that. So just use one or the other. The IOR Level is really there for backward compatibility, or for people who don't understand the IOR itself and just want a simple scalar value to adjust the reflections. So just use one or the other.
Wait, let me get my bachelor degree in lighting physics and math first.
What the ior never adjusted the specilar ior pre 4.0
Than what did it adjust, im totslly baffled. I dont understand why they have separate ior values now. I come from a different engine. And the ior is for specilar or glossy finish. Only if you had coating would it introduce a second ior, but that was for the coating only.
Was the ior pre 4.0 only for the metals than? Very weird, i never new this
Until 4.0 came out, the IOR in the Principled BSDF only controlled refraction of transparent objects (it also correctly control reflections for them), but it otherwise didn't do anything. It didn't control specular reflections like most other render engines. So that was definitely confusing for people who were used to the IOR controlling reflections. So they've made the Principled BSDF in 4.0 more consistent with other render engines now.
@@christopher3d475 man now I understand. I also come from different engine. I used These Render, a full spectrum physical correct engine. It has tons of settings in materials which cycles still doesn't have. Was so nice to create materials in there. It is not node based, but layer based. You make materials using base components and stack them. Then use masks to show what component at which spot.
I am glad we also get proper coating now. Ps mostly the coating causes that effect on cars. Especially the thickness. Current thickness is hard coded, still not physical correct. But it's getting there
@@christopher3d475 man now I understand. I also come from different engine. I used These Render, a full spectrum physical correct engine. It has tons of settings in materials which cycles still doesn't have. Was so nice to create materials in there. It is not node based, but layer based. You make materials using base components and stack them. Then use masks to show what component at which spot.
I am glad we also get proper coating now. Ps mostly the coating causes that effect on cars. Especially the thickness. Current thickness is hard coded, still not physical correct. But it's getting there
nice outro 😉
Great tutorial, but there is something about your renders that don't look realistic. Clean but they are missing something 🤭. Can you look into it and do an explanation video on how you can take it to realism? Something about the wood on the chair, tiles, towels, the sculpture... (what looks right it's the marble counter and the items on it - the right corner). Also, the rough copper you used on some items looks flat somehow,.., especially that radiator behind the tap above the bathtup)
Thank you, but I'm pretty sure you could explain this in 8-12 minutes 😆
As if 3d graphics wasn't hard enough for beginners they now have to understand refractive & reflective physics just to do a "fluid in a glass" simulation which, to me takes the "fun" out of 3d graphics. It's a whole lot easier to just put the slider on max & min values & see what looks best & run with it. 🤔
this movie could be made in 1 minute..
The same as IOR in blender 2.x and 3.x 😂