The Awesome 4.27/UE5 Update Nobody Is Talking About

and in 427 you'll notice that our glass ball here is casting shadows hey everyone welcome back it's great to see you now i know i know unreal engine 5 is the shiny new toy right now but for dotavas still working on real engine 4 forward 27 has some pretty major changes to the way that ray trace translucency or glass is handled so not only is the setup required different they actively made it better but they didn't tell anyone it's not in the release notes or anything so let's dive right in and i'll show you how to set it up after i finish my coffee oh so before we get started i'm just going to show you a quick example of why the 427 update to raytrade translucency is such a big deal so what we have right here is 426 so we have the arch physician with a glass material right here so notice how you know it doesn't integrate into the scene very well there's no shadows nothing and now in 427 you'll see that raytrace translucency casts shadows which it did not before in 426 this update also affects ue5 this is quite possibly one of the more exciting changes that came in 427 the first things first let's talk a little bit about what you need to set up in your project and how you should set up your scene to get raytrade translucency to work it should go without saying that in order to get ray tray of translucency you need to make sure you have your ray tracing enabled in your project so i will include a link in the description below on how to get ray tracing set up correctly in your project i shouldn't have to tell you this but you never know next up we need to set up our post process volume correctly clicking our post process volume in our scene let's go into our details panel and in the search details we're going to search for translucency so you're going to want to make sure that your translucency is set to ray tracing and not raster and we'll just leave it like that for now that's really the important thing here next up is the material now it's important to keep in mind that there are some pretty major differences in the way that 427 handles translucent materials versus 426 so let's move on to the material now the most important thing you need to know about the material is you need to set the blend mode to translucent right here okay after that scroll down a little bit and in the translucency tab right here you need to set the lighting mode to surface forward shading okay this is the most computationally expensive lighting mode available but it will give you the best results now you'll see that my node tree here is extremely simple okay we've got five nodes first of which is the base color which i've set to black and you'll see what happens when we tweak the base color here you can kind of see this in the material right now i'm going to leave it to black because i think it gives the best results next up is the specular now contrary to 426 the specular node no longer controls refraction okay for those of you who've watched my previous ray trace glass video specular used to control the refraction but that's no longer the case so you'll see right here if i set it to zero notice how pay attention to the highlights of my glass ball right here they are no longer as bright as they were if i set it to one they pop a little bit more now specular by default has a value of 0.5 i like setting it to one because you'll get a little bit more pings in your highlights as i can demonstrate right here okay if i set it to 0.5 as is the default value you'll notice that the reflection on the glass is not quite as bright as it used to be if i set it back to one you'll notice it's very subtle but glass is very dependent on reflections so i increased the specular value to one for this reason next up is the roughness which i said the 0.1 but it can be you know zero point one point two as you can see here you know it controls the roughness of the glass keeping a low value will ensure the most realistic results so anywhere between 0 and 0.1 is fine next up is the opacity and opacity you kind of need to have something there you can't just have the opacity to zero because as you can see here we lost all our specular highlights right here and if you set it to one it's just uh opaque material at this point right so you want to have it low enough that it's translucent but just enough so you can see your specular highlight so a value of 0.1.2 seems to be the best so of course there's no right or wrong answer here but i like having the 0.1.2 roughly around there and lastly is one of the major changes in 427 and ue5 and that's the ior also known as the index of refraction okay so now the refraction of your material is controlled by the refraction pin which is how it should always have been but that was not the case in 426 and earlier so now for example if i adjust the value of my ior you'll see this controls the refraction amount so you'll notice if i set it to one there's no more refraction consider 1.1 there's a little bit and if i set it to two for example now we're getting some different results everyone who's worked in vfx or archviz knows that the ior glass is 1.5 you can find information to back up the statement online pretty much anywhere so 1.5 is the value i'm going to use for glass but feel free to adjust this based on what kind of material you're making now previously in 426 in order to get a accurate ior value we had to divide the ior of air by the ior of the material in this case the glass which gave us a really random value of 0.66 and that was really irritating to work with because it would just no other renderer works that way but now you can just enter the actual ior of your material right here and in the case since we're working with glass it's 1.5 this makes a lot more sense for anyone who's ever worked with arnold v-ray redshift octane whatever so big thank you to the dev for getting this set up correctly now so again you may think it's really weird that the refractions inside the glass ball here are upside down but then again that is how refraction works in real life this is how a glass ball would look in real life as demonstrated right here right so you can see right here that the refraction happening inside this glass ball everything is upside down inside it this is how it works in real life again this works for both 427 and ue5 now you'll see i've brought in some more complex shapes in here to see how ray trace translucency works on more complex models and you'll see this glass right here totally black and the statue has these weird black lines in it right and that's because of the ray tracing setting the inner post process volume so let's open up post process volume again and again in the details panel let's type translucency and you'll notice here we have max refraction rays by default it's set to three you're going to need some more rays to get a really proper refraction in your glass okay so i'm going to set this to 10 and now you'll see we're getting some pretty nice results in our glass here same thing with our statue right this actually looks pretty good especially now that it's casting shadows properly this is going to make your glass object feel so much better in your scenes from now on now one thing you might want to change in the post process volume as well is the shadows so notice on the glass here we have these kind of dark patches and same thing on the statue we got these big dark areas here so what we can do to fix that okay and again this is really a case-by-case thing this is not a global thing that you should just do this is just a tip that may help you in some cases so let's click on our post process volume again and in the shadows section of the raytrade translucency we're going to set it to disabled and notice how now our glass feels so much better right if i reset it to default one more time you'll notice uh these dark areas don't look that good but setting it to disabled in some cases can be very beneficial but again not always right so let me unhide that sphere that we had before and you'll notice that things kind of feel weird in the sphere because it's not getting any shadows refracted in it right so let me show you what i mean so i'm going to select my post breakfast volume and i'm going to set the shadows to area shadows for example and you'll notice like okay in our glass ball here it's nice because we're actually seeing the shadows cast by object that it is refracting and if i set it to off or disabled it seems kind of feel a little bit odd right so again this is not a setting that is going to work in all cases you need to be the judge and figure out what works best for you i just figured i would show you how to get some various results and that concludes this week's video folks thank you so much for watching just so you know i'll be taking a bit of time off this summer to enjoy better the sunshine somewhere so don't worry i'll be back with some really exciting news coming towards the end of the summer so be sure to hit that subscribe button so you don't miss it and so with that being said have a great summer and i'll see you soon

Channel: William Faucher

Views: 75,415

Keywords: UE4, Unreal Engine 4, Unreal Engine, Cinematics, 4.26, UE4 4.26, UE5, Realtime, realtime rendering, rendering, CGI, 3D, 3D Artist, ue 4.27, 4.27, ue5, unreal engine 5, unreal engine 4.27, raytracing, raytraced translucency, translucency, glass, rtx, nvidia

Id: p8TnqBiWKyY

Length: 9min 18sec (558 seconds)

Published: Fri Jul 02 2021