Filament tutorials/shaders/lights?
marble
Posts: 7,500
Like anyone else who has installed the latest beta releases, I have tried Filament. I have to say that I'm somewhat underwhelmed at the moment but I'm prepared to accept that I just don't know how to use it. I don't know how to light scenes or adjust the materials or apply Filament-friendly shaders. So I am wondering when we might get some tutorials and products specifically set up for this new engine (is it even a render engine?).
My guess is that we will have to wait for a General Release which has become a rare even this year (only one?). If so, I hope that there are a number of PAs toiling into the wee hours creating those shaders and lights, etc., that will make our Filament renders look half-decent - especially skins which is the biggest disappointment for me. Meanwhile I have a couple of questions:
1. For those becoming experienced with Filament, are you finding that it hogs VRAM more or less than IRay?
2. For those same users, does it work with CPU and, if so, how well (or how fast)?
I'm in the middle of a quite intense project at the moment and I'm having to stay with IRay (even for my short animations) so I don't have a chance to experiment right now.
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You might try this thread :)
New DS Filament Render Engine https://www.daz3d.com/forums/discussion/442982/new-ds-filament-render-engine/p1
OK - yes, I had forgotten that because it is in the commons and I expected to find the discussion in the DAZ Studio Discussion forum. I'll read though and see if my questions are answered.
Well, since we now already have a thread focused on Filament lights, here's my limited understanding so far:
- Filament does HDRI (yay!) but it's about 300% brighter than iRay, so I must turn it down for my scenes. It will easily overpower all other light sources.
- The dome is sometimes drawn in detail and sometimes as a blurred light source only. No idea how/when/why.
- Spotlights work BUT each spotlight has a light cone. With iRay/Textured the lenght of the cone does not matter, but with Filament, light just stops abruptly at the end of the cone. I must resize my lights.
- it doesn't do emissive surfaces.
- it doesn't do Subsurface scattering, and typical G8 figures use that heavily. Surfaces with low/no SSS (incl. at least some 3DL skins) look better in Filament.
- Shadows apparently can work but I have not seen it so far. Objects do not stop HRDI light. Nostrils tend to glow.
- Filament preview likes to hang occasionally, sometimes for many minutes
I'm hoping DAZ will keep improving it. It's so FAST. Posing your camera so that the scene is in harmony with the HDRI background is way more fun in Filament.
Filament is used as a draw mode not a full render engine in Daz Studio, it uses PBR shaders that are based on reflection, same as Iray shaders or any PBR shader. You don't need to create any separate shaders for use with Filament , it is not a thing and it doesn't use its own special shaders , you can compare it to Iray Draw mode Interactive .
It uses Distance light and a couple of spot light but there is limitation , it also uses Environment as IBL so HDRI with sun will not produce shadows , only reflections of the environment .
The surface material in Filament don't reflect other surfaces or objects , so using emitter light shaders will not work, there will be no global illumination for the same reason .
Simple Metallic shader setting works fine as they do in iray
Metals and nonmetals surfaces
Nonmetals:
Base Color maps (Albedo)
Roughness maps ( micro surface )
Bump/Normal maps
----------------------------------
Metals
Metallicity map or value set to 1
Base Color ( specular)
Roughness map ( micro surface)
Bump/Normal maps
and that is all about , no magic there or special thing you believe you need .
It is a Draw mode to help you better set a scene for Iray, see where the Environment is etc.. as that was not possible before with OpenGL
PBR materials should work across all PBR engines at the same level, but the quality of the final render depends on the end rendering engine as in our case is Iray, the final render engine .
You can use Filament to compose your scene, animation or a concept art scene , don't see it as your new render engine as that is not . It is the same as OpenGL preview vs 3DL rendering
If DAZ team installed the full Filament render engine , things would be different but you will need a good cards to render things out as you do with Iray so make not sense
Filament in D|S is a real time PBR draw preview , there is no rendering time but FPS, and it uses as much of a memory as anything you throw in the scene.
You can improve the quality of Filament Draw mode under Settings of Interface in DS as you would do for OpenGL preview for example performance vs texture details etc..
as with all PBR engines you should not use it with an empty space, your can load your environment map or IBL and use direct light or spot light to have a shadows of course you will need a ground to catch the shadows, you need to adjust the environment light ISO ( Filament option node need to be created for additional control of light and AO ) so it don't wash off the shadows from the spotlight, in short the light need to be proper balanced .
I made a lot of comparisons on a simple PBR materials and it works just as expected
If you create a proper simple PBR shader it should work fine in both Filament and Iray, but not all Iray's shader functions will work in Filament or looks the same as again it is a DRAW preview mode only, simple basic !
For example human figures where you're gonna miss a lot of shader settings like for example SSS and others.
A lot of programs use this type of draw mode to help the artist in visualization of the final shaders they are working on , it is estimated and not the final look but very helpful .
The lack of reflection between materials make it less usable as you may wish as it will never look right and should be not used for a final work, it is great to render out a preview animation as it is fast so you can catch up on little mistakes before final rendering . Setting up single materials without firing Iray , or see the environment location so you can properly set up your figures , especially for those that use CPU or low end cards for rendering, is gonna save some serious power consumption and time .
So that is all about, sorry if this spoiled your expectations , but it works the way it meant to do.
I was very surprised to see it as we already have Interactive Draw mode for Iray but it was not a real time rendering and heavy on GPU , Filament Draw mode is simple, PBR based and in real time ,especially usable for people creating assets for games using D|S as the visual results are very closer .
I am throwing in some of my early comparison tests using Filament/Iray base PBR shaders , as they looks mostly the same on a whole platform of software
On the first, there's in the change log that looks relevant
http://docs.daz3d.com/doku.php/public/software/dazstudio/4/change_log#4_12_2_58
Thankyou - especially @MEC4D - for the detailled responses. I didn't expect anything further after Ivy's variation on the RTFM theme but both threads are helpful to understand the concept. In my experiments so far, I have found Filament to be clunky as a viewport draw mode so prefer OpenGL even with all its drawbacks. I wonder why they went with Filament rather than updating OpenGL which, I gather, is far better than the version we have in DAZ Studio.
My main hopes for Filament were as an alternative to IRay for short animations (IRay is just not practical for a couple of hundred frames). But my animations have humans fairly close to the camera and they don't look good in Filament. Skin, in particular, looks pretty poor so I was hoping that someone would know how to make skin look a little more realistic. I came to similar conclusions with Eevee in Blender but I have since seen some pretty good Eevee approximations although I'm not yet skilled enough with the Blender node system to tweak it myself.
there is no manual
-Filament does not use HDRI only IBL , HDRI don't works , it use IBL for Ambient light ( Reflections Only ) so HDRI loaded that have sun will not works and not produce shadows .
-Filament don't show 300% brighter , all my HDRI maps I used in early testing show the same brightness in Iray and Filament ( beside the one that have sun in Iray ) unless you adjust it using the Filament option node what will set the calibration off and never match the Iray light settings , I only use Tone mapping to adjust the light so I have closer result in both .
When you using Direct light and spot light the scenario change as it looks much dimmer in Iray so harder to get the proper results , I wish for improvement
- Filament will show lower resolution of the actual Environment map and in IBL , if it is is blurred it will show blurred and if normal details it should show normal details at lower level of resolution kinda as Iray Interactive mode
-Again the Spot light create funky light and worse effect than OpenGL preview, the fall off is horrible , PBR is based on reflections only , that maybe it don't works the way we expect it to work in Filament, it has own limitations
-emitters are shaders , Filament don't reflect other objects surfaces so emitters will not works and there is no global illuminations , again only reflections from IBL environment and Spot light /Distance light and that is, same for SSS and other Iray shader functions, limited and basic .
-shadows works from Distance light and Spotlights, it need to be activate under Parameters /Light /shadow , but if you have environment map on you need to adjust it to lower level so it don;t wash off the shadows
- IBL will pass through objects , again it is only for PBR reflection based engine , not fund rendering and works same way as in other programs I use , you can use AO settings in Filament to limit it a bit
- I did not experienced any hanging on , you may adjust settings under Interface in D|S , it depends on your system and graphic card too , it is real time rendering based on the frame rate of your system , I see sometimes things turning blue when loading shaders or maps from the library , just for a second .
and I agree that having the ability to see the Environment map without firing Iray or your GPU is a big advantage compared to OpenGL, a big improvement and I hope it only improves .
Interactive Iray mode does a lot more than Filament , but it is not as light on your system as Filament , other way what is the point of having it if you can use Interactive mode anyway to get better results before final Iray rendering .
It was meant for better preview than the old OpenGL offers and not for rendering .. it's not full render engine
Filament is very simple , there is no need of an understanding more as you have already with Iray. Follow the PBR rules and you will find your ways in both Filament and Iray
Excellent post, MEC4D, thank you. I'm now trying out some of the things you listed.
@Richard: I already run beta .60 so I have that change already. I was under the impression it is for regular lights, not HDRIs, but not sure.
In the meantime I figured out somthing that confused me: it looks like under memory pressure (iray render) both my 8k HDRI map and the spotlight gets dropped. When going back to Filament preview later, those are not (always) loaded again, so you get the default HDRI and no spotlights/shadows.
(BTW I hope I didn't come across whiney; that was just the essence of what I learned. Filament is cool)
When I said "variation" on the RTFM theme, I meant the other thread rather than "Manual"... ahh, never mind.
You have a point here , that is the reason I reply to you as I saw your early posts .
If someone go fishing with a pan, that is their choice, hammer may be used for more than just a nails but sadly Filament draw mode is not multi-functional new render engine , and not used in D|S the way everyone expected .
it is not for rendering and definitely not for human skin shaders or any other complex shader as for that I still have to fire the Iray engine .
Original idea for Filament was to bring it to Android phones and system so people can enjoy better VR and other stuff , and the full engine do nice job , but we don't have it all in D|S, again it is just a draw mode for PBR materials based on reflections only .If you want to have great results you need to stick with the PBR values and settings , of course not for human skins or complex surfaces . It is basic !
You think Eevee in Blender does a better job ? nope , there is no global illumination and a very simple engine , the light is not accurate , it is just for preview and not final render engine and can't compare with final cycles render .
Who knows maybe the future bring us a real time full game render engine to D|S but it is not Filament and not now .
I use Filament type of engines in my other programs and they do exactly the same as in D|S so I don't expect anything more here but happy to see it for now as for me the old OpenGL is totally useless and hoping only things get better in the future .
It would be not a long manual Wendy , too simple to bother with manuals
The only thing I ever touch is the Filament Options node that you have to create to adjust the AO bias and resolution when working on a setup shader on a simple object in the scene , the rest like light I setup under Tone Mapping and enviorment so if I want render out in Iray it match my lights . Of course the spot and distance light will shine brighter in Filament than it does in Iray , as the reflections in Filament process it differently , that is only negative aspect I found about.
I also use distance light with shadows as that allow me to have better visualization of the shader in light and dark areas . As you know the base shader color can't be brighter than the light source what is 255 255 255
You want stuff to looks nice, you need to follow the simple PBR values , and don't use complex shaders like skin etc.. I tried it all long time before you get hands on it so I know the possibilities.
I prefer to use it with Metallicty/Roughness shader than Specular based shaders as the last don't always turns the way I want .
Originally Filament is for IBL , PBR is reflection based system as everything is shiny in a real world. Using Spot light or Distance light will never works , as that is the same like you fire a spot light in a vacuum space , all you will see is a black object with a small specular reflection in the middle . And since surfaces materials don't reflect from each other under Filament Draw Mode you need Enviorment map to experience the full effect of it and it needs 360 degree IBL to work proper , Distance light or spot light are additional stuff , as it allow you to replace the missing sun in your HDRI and add shadow , most PBR based programs with this kind of engines works the same way, HDRI and a Distance light with a shadow since it can't use the full potential of HDRI
for the second part of your question Richard may have better answer as I don't know exactly what is happening in your case , it should not , maybe a bug I don't know
Ah!
- "Filament Draw Options" node. THAT is one thing I was missing badly. Never found it before (came together with Tonemapper and Environment options in the Info panel. I ignore those because they don't make sense to me, they add nothing new?). Simple surfaces now look similar enough to iRay. Skin might need an extra tweak option or two to adjust for "should be darker due to subsurface material".
- "Ugly big bump maps", that is related to Menu > Edit > Preferences > Interface > Texture Resources (default 50% Quality). 100% looks decent (and I don't think my GPU cares, this is no Crysis after all).
For a pro all this might look trivial, but to an amateur this isn't intuitive. I'm considering writing a "readme_filament.txt" on this topic, I'm not that qualified, but better than nothing.
(trying to figure out how to recreate the "occasionally drops Environment map" issue. The fix is to select "none" and then select it again, then it will re-load.)
Thanks for those MEC4D, I've tried some adjustments because some surfaces look like a 'coat of ice' is on them, your PBR Swabs should help.
Filament Draw Options node have their own separate settings for the light intensity and Environment under Filament only, and not affecting Iray rendering.
It is there to calibrate better the Filament mode so it matches better lighting in Iray in some cases . Or if you want to have shadows under Filament using Distance light or spot light you will need to adjust the settings of the Environment under Parameters of Filament Draw Options Node .
The Tonemapper and Environment nodes you see under scene are for Iray and are a key to everything , if I don't use distance or spot light under Filament mode I use only Iray Tonemapper node to adjust the lighting and setting and it looks exactly as good in Filament as it does in Iray without spending too much time on it .
Once you add Distance and spot lights , things going to change and the result will be not the same when rendered with Iray , for that you have the Filament Draw Options Node and all it's settings
Once the Beta becomes a General release there will be for sure a manual regarding the all new options , for now everything can change until it is ready for the public general release ,so making manual now is not the right time , but some temporary guide for others would never hurt for now so they can beta test this build and not just messing around with it and complain about the cake that is not yet in the oven, if you know what I mean.
where is this Filament Draw options node?
I found tonemapper and environment load with the advanced iray render settings under render presets in my library
my drive:\My DAZ 3D Library\Render Presets\iray
Create menu.
Some shaders may looks weird under Filament , especially the one that has more advanced settings and not just a simple basic shaders , Specular/Glossiness shaders with a top coat may looks like ice on top of the surface but still render correctly in Iray. Adjusting them to Filament may not render fine in iray and you should not do that.
Filament will show some simple shaders just fine and very accurate but once it get more complex it will not works as it is just a draw mode and not final render engine .
For example I created ground shader with stones and water between , separately the surfaces was looking just fine at its own under Filament with proper PBR values for bars color and reflections , but when combined into one map the effect was not what expected , it needed additional control map to work proper with the water and stone reflective values as you may be surprised that Water has less reflectance than a stone , skin or plastic
that why things appear darker when they are wet and lighter when they are dry .
So if you work with Metals and Nonmetals as a separate materials you don't get in too much troubles setting it up , it is easy and values are everywhere online to test it out , just don't forget about the reflectance values of your materials , as much important as a right Albedo Values
Under Metallicity/Roughness shader
the common default reflectance of nonmetal material is 4% , by default D|S have this setting already what is 0.33 for the Glossy Layered weight and 0.50 for the Gloss Reflectivity
that include materials like Plastic, porcelain , paint and most common surfaces as the range of the reflectance is very small
But when get about nonmetals materials like Ice, Water, Glass , skin or Diamond it is little different
Diamond is 16% vs 4%
Water is 2% vs 4%
Ice is 1.8 % vs 4%
Skin 3.5% vs 4%
and it may be not a big deal when you look at the object from front view , but once the light hit from the side or behing you will see the huge difference and your surfaces melting together under one plastic coat
like the little example below
so I would not get too crazy focusing on Filament and how things look, it is estimated , it will never looks exactly the same as in Iray as it is just a DRAW mode and people need get over this . Waste of time , same as comparing 3DL shaders to OpenGL preview in D|S
Same with bump maps and normal maps , bump maps looking actually very accurate in both Filament and Iray at the same level, but not all Normal maps will , Normal maps with very fine details will looks fuzzy in Filament or even a Game Engine , it works best with Normal maps that have bigger elements and for the smaller details go with bump maps and for the micro details you have roughness maps according to PBR book for the real time rendering .
I wish DAZ Team created a separate shader mixing option from the gecko , for Metallicity, Specular and Weighted as the way it is only confusing even more people that mixing up values of all shaders together even if it not works at all , using Glossiness specular with Metallicity etc.. and learning nothing from it
When I see a promo shaders for Iray I can tell it is not good just from the promo already , the system in Iray give us opportunity to skip adjusting things , just throw it in and render , that was the goal , not adjusting it for each scene or lighting , that was the old ways that worked only for one scene and lighting.
I guessing that why so much confusion with Filament Draw mode , we are back to the beginning of PBR , if you don't learn now you gonna stay confused forever and even more with future upgrades
with "YOU"' I mean the users
and coming back to the image I attached with combined materials on one map, you can see the difference in reflectance I was talking early about , and maybe not huge value changes but the final result change dramatically , not only additing details not seeing in top image , but also changing the overall look , based on true world values and not my eyes, as much as my eyes love the reflections in the water on top of the image but the rest is not they way it should because of that .
That are the little things that should be not ignored just because someone don't care about or need it, that are basics , you skip the basics now , you get lost later .
No matter hobby or pro I think it is worth the time to learn the basics of your favor program other way it is just a hause of cards .
Wendy look on the screenshot
in the first image you can adjust the Ambjent Occlusion , make sure your objects in the scene are not pure white or pure black
you can adjust the resolution, bias and power of the Ambient Occlusion
in the second image you can add Distance light and create shadows
Use Environment maps that don't have a sun for this option for better result .
Create new distance light , click on it and go to Parameters , under Light/Shadow select shadow type from the menu or there will be no shadow
Next select Filament Options Node and under Scale : adjust the Enviorment to lower values if you don't see shadows or use the Distance Light scale to Incrase the light to your liking .
The Tonemapping in Filament options node is to adjust the overal brightness of the scene under Filament
All options under FON don't affecting Iray final rendering , it is all separate
When I want to calibrate the light conditions in Iray and Filament I only use the Iray's Tonemapping and Filament AO settings (Screen Space) and use HDRI without sun for easy setup
@Mec4d: thanks, once more, for the deep dive. I've read it all twice and experimented some more. (Aren't you the guy who said 'bah it's all so easy who needs info'? :P )
With limited experience it's intransparent, I've spent much time trying to get a handle on the iray Uber shader, skimmed the MDL spec and other things, but nothing tells you, for example, what Glossy_layered_weight vs. Glossy_reflectivity is, how it interacts with the dual_lobe_* parameters and the top coat; all trial and error. And yeah, it doesn't combine with metallicity. Erh, of course not, never! (I tried it out, it doesn't. ah. ;).
Now there's a new bunch of rules how all that interacts with Filament. I don't have to know those details, but I prefer to.
I see three user groups for Filament:
#1 better preview for iRay (most of us)
#2 just like the different, less realistic look (might convert some 3DL die-hards)
#3 would prefer iRay but won't pay the price (regular laptops, animators)
I'm firmly #1. I care about
a) pretty. Seriously that's quite important to me, I look at this preview a lot and I prefer to see pretty graphics. Fil is a very big step forward over OGL.
b) close enough to iray so I can set up as much as possible in Filament (now works for me, for posing; hdri dome; rough shadows; basic lighting) which is great because it is so responsive.
For #2 and #3 I imagine that Fil in Daz will do nice things when a scene is created for it. Not Unreal nice but pleasant.
Open issues right now (those can't be solved by the user, right)?
- hair with cutout opacity (flickers on and off)
- transparent stuff and skin does not give a similar preview currently.
- lights are harsh when you have no dome (every light is a point light to Fil -> hard shadows, high contrast bump maps).
- no emissives. Scenes based on that kind of light will be dark, you'll need an extra Fil light that you have to toggle off for iRay renders.
...and yah, it could be a bit more stable, I'm having more issues than usual. Might be fighting with the other engines over the VRam.
That's all I can think of. I'm quite happy now that I found the Fil Options node.
Now on a technical side and GPU usage
Filament still use the card when moving the scene with a Stonemason bigger set
I had hard time to rotate the huge scene around where it move smooth like a butter in Iray even on a CPU
It is slower than Iray or OpenGL when get about bigger scenes and camera movement , sorry Animators your dream just crashed
So if someone else told you again that they are so happy about Filament that they don't need a proper graphic card or system , let them dream , they gonna chock faster with Filament than actually Iray once they reach their limitation.
Real time render engine is hungry for power and memory , just like a game engine
Now imagine if D|S had a full Filament engine , nobody plays PBR based games on CPU , but you can still render with it in iray , it need less resources than real time rendering engine
And if you want your images to looks like 30 years ago be my guest , you will only make a bad name for Daz Studio and yourself
sorry I was just shocked what I just saw in the forum thread , the Earth becomes Flat , an Armagedon of 3D , have a mercy !
I understand your needs but a light that passes through object is not a pretty graphic , a light that fall off weird way is not a pretty graphic, a skin that looks worse than 30 years ago is BAD , it is not made for making graphics it is a PBR DRAW mode for preview and that is all about at last in my book and can't argue on it or change my mind .
You good some good points as well and happy to see it ! that what it was made for, to help you speed up the settings and move forward.
Things like it is realistic or non realistic don't excist , it is bad or good , you can still make a cartoon style and use the proper values that the engine need to work with , it has own rules !
I am really not in a good moment to go into shaders conversations, Reflectivity play a huge role under Metallicity as you don't have only Metal materials but I guess you need to learn a little bit more about the basic of PBR so it will be easy for you to understand what is going on with Iray shaders , the names may not always be exactly the same but the functions are . You need Glossy Reflectivity for dielectric materials and yes there are no manuals explaining everything about it and doing trial and error put you nowhere closer to the truth , it is complicated and messed up and clumpy but it works , trust me it does
Transparent stuff set up using opacity is not a real physical property, it don't exist in a real world , Transparent stuff in real world use IOR or are translucent , the last will not works in Filament but other DO , it is only a partial engine and same for the skin , if it was a full engine you need as good card as for Iray so make no sense right ? why do we need another render engine that is slower than Iray right?
Lighting doesn't work since there is no global illumination so it is a light in a vacuum space far away from Earth , and it is what it is . What you think would look glass in a vacuum space ? with a 1 sun ? you will see just one reflection of the sun, small spot and nothing else . But if you did your homework, you could place an object behind it and see it better , of course not full renderer but at least something like a preview.
You wish to have stuff that sadly was not made to use with this draw mode and nobody can make it better, it is what it is , case closed !
and btw I am a girl and I find it very easy .. at last the parts that I am good at so I can speak about, did not wasted my 22 years in commercial 3D for nonsense but learned things with passion but mostly by the book , everything have its rules that helps you to achieve your goals , I share sometimes my stuff I learning from the past to help out others that are interested to learn something new but I am afraid there are no many here that want to know
I am glad that you found out couple of stuff that will help you in the routines with Filament , most of them are exactly made just for that , but if you want it to be better , you need to set up them by yourself and by the book ;) for the best result and close an eye for other things that are not worth talking about as it change nothing and there is no solution for that, I tested the possibilities a little time before you got your hands on it just to see if there is more , but there is not. Who knows maybe the future updates bring something new to it, I don't know, all depends of the DAZ programmers and their decision , but I see that most of the people here are not ready and many of them never will be .
Happy rendering !
@marble I created for you a set of info that will help you and others to set the proper shader not only for a Filament but also for Iray, it is a basic shader setting that works on most programs and game engines and Filament PBR as well. It is simple because Metallicity shader is the simplest of them all , it don't need a lot of resources to run proper and render fast in all light conditions , but the way it is presented it can easy to be mixed up with less good results
That are the basic for PBR Metallicity Shader Mix that works fine in Filament and Iray without huge hassle , all you need to have the proper Albedo/Diffuse maps for best easy result and fast rendering , don't use settings that are dimmed off in the shaders even if it change the look in the viewport , it will be not accurate and you may just make your material render extra longer as it really should , it is very easy to screw with one wrong move .
Remember objects can't be brighter than the light , avoid using. 255 RGB white color ( that's the color of the light ) on surfaces or RGB 000 pure black
No matter if you do stylized Art or Realistic use physically accurate values, if you do good it will always look good in any light conditions , as nothing looks better than reality , even in a cartoon style ! so why settle for less if you have everything in front of you ! Once you grab the basics the rest will be easy , no need for a super lecture or 100 of tutorials or manuals . Simple is beautiful ! you can thank me later !
Enjoy !
Below I make visual card for you to save for later in case you need to be remembered
@MEC4D : Many thanks. I'm just on my way out right now but I'll read it in detail when I get home. Your efforts are very much appreciated.
That visual card is great! Really helps me sort out what I (and Filament) do and don't really understand.
If I may ask two things I'm not sure about:
1. I've read that non-metals always reflect white (untinted), only metals change the reflected color. You say metal reflection tint is controlled with 'Base Color'. Doesn't that mean glossy color should _always_ be white/grayscale?
2. bump vs. normals (yawn, I know). I've learned (from another engine) that bump and normal maps are basically two methods to describe the exact same thing (kinda like png and jpg are two methods to encode the same picture, with the same result). In some scenarios bumps automatically get converted to normals for performance reasons (if I have two bump values +1, +2 then I know the angle between them is 45 degrees). Then why is the result in iRay different, is it because the maps are usually created from different sources?
As always, thanks for your insights.
We are talking about Metallicity Workflow , no Specular/Glossy workflow that are 2 different things and can get easy mixed up.
Metals use the Base Color as Specular-Color-Brightness channel once the Metallicity is turned at value 1 , Nonmetal use it as a diffuse/albedo once Metalicty is turned to 0.0, Nonmetals don't have any colors in reflections and the glossy value is most for all materials at 4% and already setup by default . So your fingernails and your skin will always have the same glare at an angle, even with nail polish , the only differences are the roughness so it appears more or less shiny . Things look more shiny because they are more smooth than other materials and not more glossy . People have a hard time to understand it with Metallicity workflow
you should leave the Glossy Layered Weight at 0.33 and Glossy Reflectivity at 0.50 , no colors no maps under this channel, not for Metals or for Nonmetals , you should adjust only Glossy roughness , The Glossy Color channel you see there should be ignored under Metallicity shader , unless you have situation where 2 types of Nonmetals materials are on one map and you know exactly the values , then you can use the Glossy Color channel to control proper the glossy values , but the real function of it is for REFLECTANCE .. and the maps should be used for nonmetals in grayscale for example water on a wooden floor ( water reflectance 2%,wood 4% )and works only in Iray . Metal materials don't use this section , their colors and brightness are controlled with the Base Color. (Specular-Color-Brightness)
Regarding BUMP and Normals , Bumps maps are like displacement maps just the details are finer , it goes only in one direction Green- UP so it is called height maps as are displacement , with the difference that displacement displace the 3d model in the object space but still only in one direction Green- UP
Normals works with 3 directions that why you see the 3 colors, each color represent the direction , Green is Up or Down , Red is Right or Left, and Blue is Front or Back where bump map goes only up, but Normals don't displace the 3D model, it bends only the light and create shadows on the surface creating an illusion of displacement for that reason it is used on low poly models to make it looks like a high resolution.
Then you have a Vector Displacement that is the Childlike of Displacement + Normals .. it displace the 3D model in 3 directions
The difference in Iray is that it create Global illumination , it reflects materials in materials and objects in objects , it bends differently the light and shadows than in Filament Draw Mode
Bump maps can be created from photos , but converting bump maps to normals is not really a good idea , bump maps have only one direction, normals need 3 directions so what you are getting is normal with the functionality of a bump map , same stuff different name .. The best Normals are created from a detailed Model , 3D scan, or displacement , to have really accurate Normal map from a photo, you need at last 60 photos of the object from all angles to extract the Normals , or you just convert it from a single photo and use it as a better version of a bump map, but as I mentioned before , the best results with Normals in Filament or overall are on a little bigger details and for the smaller use just bump maps.
Metallicity/Roughness Workflow .. Base Mix
Filament and Iray PBR is based on the microfacet theory, This mean that each surface have a micro planes like a little mirrors that reflect the light in direction based on its Normals.
For Non-metals it is around 4% +/- and for Metals around 70-100% and controlled separately in DS
The reason why we see one object shiny and the other matte are the micro roughness of the surface, even if they have the same level of reflection , that why the glossy reflectance should be not touched or changed so everything works in harmony with the light in any conditions, the same goes for Unreal Game engine and others, there is no control over it at all and it is hard-coded , if people adjust it for own light situation and eye, it is total wrong and the complete concept of the engine landing in a trash resulting in a long rendering time and other issues, it is a chain of unfortunate events and waste of time and energy.
Here is an image that shows 3 different materials , 2 have 4% default (non-metal) the other 70%-100 Metal , you see how different both materials looks with the same reflection values and will render exactly the same in Iray and Filament . That is how it works in most all PBR based engines no matter it is Unreal /Unity Engine, Toolbag, Filament, Iray or Substance Painter , one system for all .
Now with Iray we have the additional option to define better the true PBR values like no other engines , especially for a different types of materials in one map
For example skin 3.5 % have higher reflectance value than the sweat on the face 2% , skin will appear brighter than the water and that is the key , at the right angle most all nonmetals have the same level of reflectance aka Fresnel at 90-100% , the difference only are the roughness of the surfaces . Diamond have 16% of reflectance 8 times more reflective than water , that why they say Diamonds will reflect light even in very dark light conditions , but you don't use it on a nail polish , teeth, eyes or water as many do, but back to the subject..
We can control it exactly using the Glossy Color input with a grayscale map with the proper reflectance values for each material , like in this case water 2% and Stone 4% , when using this method , it only will render in Iray, however you can still plug the grayscale map under Glossy Reflectivity and have very similar effect in both Filament and Iray , there is slightly difference but if you do it the Glossy Layered weight must be set back to 0.33 value to get the proper Reflectance values , Glossy Color is great as you can set the values in Float Color by pressing CTRL and click the Color , it will open a new window where you can put your Float Color values , it is very handy as sometimes you can find different metrics of the values, sometimes % and sometimes linear color . The image below is for Iray rendering for both Filament and Iray use the method I mentioned above
The difference in Reflectance values are not as dramatic for Nonmetals and most of people will not even notice 2% of the difference , but if you have love for details why not doing it right ! nothing looks better than reality.
Remember this section of Reflectance don't affect Metal materials , only Glossy Roughness affect the Metal surface
The Glossy reflectance option under the Metallicty workflow is FO (Fresnel Reflectance at Zero), when you set it to 0.00 it show exactly the Fresnel effect of 100% light reflection at grazing angels, it use values of 2-5% for Nonmetals minimal 0.20 max 0.50 value, Ice cube have the value of 0.178 so a little bellow the 2% (0.20 ) I wish the names under the shaders was more clear for everyone and less confusing with other shaders workflow, or at last loaded separately but it is what it is .. I still need to make one last test to determine if the Glossy Layered Weight need to be set exactly on 0.33 value as the gazing effect seems to be too dime compared to metal gazing effect and they both should be on the same level of brightness .
I think it is all about for the basic PBR material settings for Mefallicity/Roughness base mixer , as you see it is very simple shader if you know what portion of that do to your surfaces and how to handle it and have a great effect in both Filament and Iray .
If you have any specific question regarding the stuff above le me know
Ok guys, here is the final cleared update for the Reflectance section for the Metallicity/Roughness Base Mix and its Standard function for Nonmetal materials.
The Glossy Layered Weight should be always on value 1 for PBR Nonmetal materials as I suspected from my early tests , and it was confirmed today.
Minimal values for Glossy Reflectivity 0.20 to Max 0.50 , materials like Gemstones use higher Glossy Reflectivity from 0.50 to 1.0 but better to use IOR for that for the full effect.
I made small card for the Reflectance , please forget about the Glossy Layered Weight values 0.33 , set it always to 1 for PBR materials for Filament and Iray .
Remember that reflectance values looks great when your albedo colors and values are set proper , that is the system about for both Filament and Iray , no matter what kind of stuff you create photoreal or stylized , proper stuff will make your engine working efficiently and produce better images of any kind . Think here about Disney or Pixar toon style or whatever . There is not excuse for laziness