Understanding arnold materials in 3ds max

okay so let's look at setting up max to Z our material so first of all we want to go into the render setup and we need to change the scanline renderer which is usually the default - Ahnold that's that then we need to get something to render so quite good things a test is a teapot just drag that into the scene and then we need some lights and the easiest thing to do is probably NHGRI I've got some HTI's from HDRI even which is really good I'll put a link in the space below and all you need to do to load that is we get into rendering environment you can do that by through the menu or you can press 8 and then we're gonna add an environment texture so fine Maps it map pop in a dialogue and I've got some HDR somewhere HDR even there we go and I'm just gonna use the 2k just plenty for what I need to do say yes all that lot and then I'll just drag it over into the compartment related to it just so I can edit things remembering when I do that to set it to incidence rather than copy if I said to a copy they won't be connected so I need to make sure that it's an instance like that and then you'll get these little drop greater angles in the outside like that so that's it it's ready to render so let's just have a look my perspective view yeah why not press shift F to get my safe frame I'll just sue in zoom in a bit always later to slow right wonderful doctrine so there we have a very bright object which is rendering no that's actually just got a standard scanline shader on it so let's give it something more or naughty so I'm gonna click on this and in the materials dialog will find Arnold and the standard surface shader and let's just drag that onto our teapot like that so now we've got the render setup we'll just do a quick test that's quite hot I think we need to change the exposure so I'm gonna get back to over here I'll get the exposure control I choose a physical camera we don't actually have a camera in the scene so I'm gonna just turn this off and then I've think an exposure value point I'm sorry I have nine more probably due for the scene said let's just try that yeah that's better so just about see the reflection of the Sun here and there's some reflections on the back of the teapot yeah if I want to I think I could probably you just change the segment's a bit like that get some nice occurs okay so the teapots a really great testing device and now we can start to inspect all these parameters so what do all these parameters mean because there are a lot of them fortunately four basic materials really only need to understand five base color specular roughness metalness and IO our base color is quite simply a way to control the overall color of material in dialectics it controls the diffuse color but in metals it controls a reflection color so what does that mean well first let's go back to libraries when light hits a surface it bounces to you create two important components scattered light which we call diffuse and reflected light which we call specular now in metals there's no diffuse light we only see the reflected light at a few slight is zero and that's the key difference between a metal and the dielectric especially a dielectric is anything that's not a metal and this leads to the metal and roughness model no the old-school spec loss model has largely been replaced by this metal roughness model and this is a artists and much more intuitive control of these reflections with two simple values metalness and roughness metal is quite simply as either on or off something is either metal or it's not anything that isn't a metals dielectric yeah and this is a semiconductor but generally we don't see a lot of naked semiconductors in our CG scenes and then we have roughness now in Arnold this is called spectral roughness base roughness is different and specular roughness is just a measure of how blurry the reflections are bigger values mean blur and when you combine the two you get this so on the Left we have dielectric and you can see that it's a kind of gray color you can just see that there are some reflections on the edges but with the roughness of five can't see any reflections at all they're completely obscured they are there it is very very blurry and on the right you can see we have a metal it's obviously a metal because we can all you really can see those reflections and let's research on this but our brains are really good at separating reflections from the diffuse of a surface so in this case it's metal so the diffusible component is black there's no diffuse component at all and we're just seeing reflections again within reference of zero we have these nice clean sharp reflections and with a roughness of five that's all we're going to get very blurry so under the hood what's going on is that in Arnold the metalness value changes the shade parameter so we get these different meanings for the same values according to whether it's a metal or or if it's the dielectric so with metals the base color as I said controls the facing reflection color and with dielectrics and controls the overall diffuse scattered light of the surface and then the specular color in metals controls the glancing reflection color and it also controls the glancing flash and coloring dielectrics but in this case the flexion colors should be always set to white oil doesn't control this for you so your perfect little bit heated make a colored specular reflection for dielectrics but they don't exist in reality in reality dialectics reflection color is always white youth nature at the physics you so this is how to set up a dielectric we said the basic roughness to zero in general but base weight to one metalness to zero and the specular color should always be white like pure white 1 1 1 and they control the appearance of the surface by in generally the base color the IOR a specular weight which should be almost 1 sometimes a bit of dimming for the edge reflection this kind of help like maybe a very 0.96 rather than one but again use your eyes and look at preference for this and there we have a spectrograph this motion controls reflection player now Iowa relates to something called the renal equation clearly don't really need to know it but all you really need to know is that the bigger I or our values increase the amount of reflected light and also increase the lensing effect of the material so if it's transparent then you'll have a bigger wonky lensing effect but as the IOR approaches one then you'll tend to just see straight through the material in fact the oil value of one is just a vacuum and rays continue in a straight line through evacuates one of their properties so in general an IOR of 1.5 will probably do it's very good starting point many tables of IOR values exist online but take them with a pinch of salt usually those tables represent very pure values and actually everything we see in everyday surfaces tends to be in pure or an alloy we all have corrosion or other gunk on the surface so use your eyes first and try and judge the strength of reflections on the surface of that material like in real life find a sample photograph of the material on to make look at your render look at the photograph and compared the tooth so here we have some examples of changing Ohio families now it's worth noting that in this particular case that I said the base colors are black and that really helps you see the reflections around the surface it is dielectric because the metalness is set to 0 and the specular color is white but in general we should never actually make our materials black they should always have some color in them but you can see that IOR of like point one or point one one point five different in terms of the amount of reflection that's going back to us and then on the right we have these very high values like 2 & 5 and actually these tend to give these more metal like reflections and in fact very high our values is another way of making a metal material and that's the kind of the old school we're making a metal - you'll just have a black diffuse color and very high IR value okay then so to say that the Arnold stands a surface for a metal set the base enough this again to zero base weight to one met on this one especially to way to one and in this case in Arnold not necessarily another rental has been Arnold if you set the metal mister one the IOR has no effect so it doesn't do anything so you miss what we like eleven no effect so we just control the metal appearance by adjusting base color specular color and specular roughness now in real life there is a slight tint to the edges of metals so the facing reflections and the edge reflections are different it is quite a subtle effect but you can adjust it in Arnold so the facing reflections are controlled by the base colour and you can just leave the edge reflect its weight or you can adjust it those color we can give it a slight tint like this so I've totally amped it for this example this is not really realistic so but you can see the difference between the white specular reflections on one side and the red specular color on the other side but normally effect is quite subtle

Channel: kenzorman

Views: 46,897

Keywords: CGI, Maths, Tutorials, arnold, 3ds Max, 3dsmax

Id: 8ISLtlyugTU

Length: 11min 33sec (693 seconds)

Published: Sat Feb 16 2019