All language subtitles for 1月29日 (6)

so with the 5.0 release of unreal

I've noticed across

many message boards and forums

that a lot of people are actually

pretty confused about some of the

changes we've had so far

notably with the lumen reflections

refractions and even

things like how do we even turn on the pathtracer

so this is going to be a very quick and dirty video

just to help clarify a few issues

that some of you may have run into

and I'll be pointing you towards some other

videos on my channel

that will go more in depth about those topics

now for starters Lumen does not require

RTX or hardware ray tracing to work

UE5 will work with older GPU like the 1070 to 1080

Lumen is not dependent on that

but those of you coming from UE4

will undoubtedly have noticed that

the lumen reflections and refraction

are not nearly as good as they were with

raytrake reflections in ue4

but don't worry

this is not a step back

there's just a few settings that we need to change

to get both the benefits of the GI and lumen

and gorgeous ray traced reflection

and the easiest way to do that

is when you're creating a brand new project

just turn on the little ray tracing checkbox right here

that's going to enable all of the ray tracing settings

but you're also going to keep illumin as well

but of course

if you have an existing project that you want to just

enable hardware ray tracing on

let's take a dive into the necessary project settings

to get that to work

we need to go to the settings tab here

go to project settings

and we're going to go down to the

rendering tab down here on the left hand side

and scroll down

and the following

settings are the one that you really need

to have

dynamical illumination set the lumin reflection method

we can leave that aluminum for now

we can override this in the post process volume later

but what we really want is

support hardware ray tracing

turned on and

here in the Lumen tab

use hardware ray tracing when available

make sure this checkbox is turned on as well

you may

get a message that says something along the lines of

enabling the skincache

when turning on the hardware ray tracing

just click yes you need to have that enabled

we're also gonna turn on the

path tracing checkbox right here

I believe it's actually off by default so

if you want to use the path tracer

you can turn it on right here

I have a more detailed tutorial on the path

tracer right here

so check that out if that interests you

and one last thing that

should be on by default but isn't always it

we're gonna search for Direct X

and be sure that it's set to Direct X12

and Direct X11 and 12

SM5 is turned on

I've seen some people who project were set to Direct

X11 and that was breaking a whole bunch of things so

just

keep that in mind

Pro Pip now with the project setting changed

you may need to restart the engine

it's going to have to recompile the shaders

but once that's done

you're good to go

and now if we go to the lit tab here

you should have the path tracer show up

and it'll work as intended

just a bit of a quick Segway here

the path traitor doesn't work with nanite

if you turn a path

traitor on with a whole bunch of nanite meshes

it's only going to path trace the nanite

proxy mesh and not

the actual high red nanite mesh

is

another thing you really need to keep in mind because

neonite is not exactly what we call real Geo

it's virtualized Geo

and the path

tracer doesn't really know how to read that

it's the same thing if you use ray traced shadows

and not the virtual shadow map that Lumen uses

the ray traced shadows will be tracing on the

nanite proxy mesh not the hi rez model

so if you use hardware ray tracing for a few things

nanite might not behave the way you expect it to

just keep that in mind

also if you've noticed that

you cannot find the Quasal Bridge

or you can't access any of the Mega Scans assets

directly within Unreal

Legend 5 like you could previously

you're going to have to go into the Epic Games Launcher

and in the library tab

in the Search Vault section you need to search for

bridge and install the Quixel Bridge plugin

to your version of the engine

once that is done

the Quixel Bridge plugin will work correctly

as intended so now with the project setting changed

I want to show you

some tips

for getting better reflections and translucency

and refraction

using lumen so for starters I've got a blank scene here

I'm going to make the lighting from scratch

so we're going to go to the Windows tab here

go to environment light mixer

and I'm going to create a skylight

atmospheric light zero sky atmosphere

volumetric fog and height fog

and so right now I have a very

very simple quick and dirty scene

I'm going to click my skylight here

and set it to real time capture

like that

so now we got some proper sky bouncing in my scene

and using the Control

L shortcut I can move my son like this

and as we can see we get this nice

gorgeous indirect lighting on the underside of this

very bare bone scene

with the quick demo scene

I know it's not super pretty

but it gets the point across

so taking a look at these five spirits here I've got a

black one an 18 percent gray one

a white one

this here is supposed to be glass using the same

right traced glass material I use in

this video right here

which again

you should go watch if you want to learn how to make

a nice glass material

and here I've got a

chrome material a perfectly reflective chrome material

a mirror ball if you will

I'm just gonna select these and hide them for now

the two problematic ones are these guys now obviously

this glass material looks like but it's really bad

we're not getting proper refractions in there it just

does not look right

in any way and on the right here I've got a

chrome material

but you'll see the reflections are kind of

they're very mediocre not super great

this is the classic case of lumen reflection

now the cool thing

about lumen reflection is

as I move the sun around

you actually see the global illumination

being reflected

in the chromeball which is great

we were never able to get

global illumination

to reflect with ray trade reflection to you before

but you know the reflections are not super great

as I zoom in here you'll see they're very

blurry and not sharp

for people who work in archvis I hear you

this does not hold up

this is

usually fine for anything that's kind of like a soft

chrome a soft metal like the table here

this works fine it's usually good enough

but for those of you who need the absolute

best possible reflections

this is not good enough

so what do we do

there's a few things that we can do here

we're going to select our post process volume here

and of course

make sure that it is unbound

to make sure that the post process

volume affects the entire scene

and we're going to search for Lumin

and here is where we have a whole bunch of

options to choose from

the one that we want right here is

the reflection section at the bottom

and we've got the aluminum reflections quality

now if I zoom in here a little bit

now to aluminum quality if I toggle this between off

you'll see it softened a little bit

it doesn't

really do that much so I'm going to leave this at 2

but what really is interesting is the ray lighting mode

if I click on this and set this from Project Default to

hit lighting for reflections

notice how suddenly our reflection got a whole

lot sharper I'm going to zoom in as much as possible

pay attention to the floor here

if I toggle this

back to default

it went from

this which is very soft and kind of blurry

to

this which is much sharper and actually does look

substantially better

it is quite a big improvement

I'm gonna go over here where I have some other

chromeballs here and in the shadowed area

just to get a different camera angle on this

I'm gonna revert this to default

so this is the default lumen reflection

and this is the hit lighting for reflections

the reflection got a bit sharper

but notice the reflection

of the reflection

right here as I zoom closer we kind of see

this

we don't see the reflection of the reflection in the

chrome ball in theory

this chrome ball should be reflecting

its neighbor here

and it sort of does

but only on a screen space basis

okay so if not a perfect solution

with a bit of a tradeoff

you get some sharper

cleaner reflections at the cost of losing

subsequent bounces

so if you have a lot of shiny object

reflecting one another

this might not be the best approach

but I did want to point out that you can absolutely get

sharper cleaner reflection using lumen reflections

with the hit lighting for reflection method here

again this is default settings

and this is with the

hit lighting reflection

so this is a very useful tip to know about

now as you know this is not perfect

it's not exactly what we're looking for

so we're going to go ahead and

instead of using lumen reflections

we're going to use the hardware ray trace reflections

which we have access to now

because we changed our project settings earlier

so again

in the post process volume I'm going to search for

ref for reflection

and you'll see here in the reflections method Lumen

I'm going to turn this off

and I'm going to set it to

standalone ray traced deprecated

and you'll see our reflections got

super tac sharp like

really really crisp and clean reflections

pay attention to the shadows in the reflection

this is lumen

and this is hardware Ray trace

everything is way sharper weight cleaner

you get much better reflection that way

but now you'll notice that

we kind of lost our global illumination in our scene

pay attention to the whole top of the chrome ball here

hardware Ray tracing

never did reflect global elimination

and that's kind of a bummer we kind of lost that

nice lumin reflection

feel here right if I reset this to lumin reflections

we get a better reflection

it's not a sharp but it's a more accurate one

but we still have a few tricks of our sleeve

so again I'm going to set my

reflection method to

ray traced in the post profit volume

and we're going to go to the

ray tracing reflection section here

and we're gonna turn on a few things

I'm gonna turn on max roughness

Max bounces

and I'm gonna set the max bounces to something like 5

and before I hit 5 I want you to pay attention to

the black spot in the spheres here

and the ceiling

so when I set this to something like 5

you'll see suddenly

boom

we now have all those subsequent bounces

pay attention

right here

this sphere is reflecting

the reflection of the reflection of the reflection

it looks much more realistic

and we kind of got our reflections back on our roof

it's not quite the same as Lumen reflection

right if I go back to Lumen reflection we do get

a more accurate

visualization

and now we can also in a Mac roughness

I'm gonna set this to 1 for maximum quality

but keep in mind this could have a

performance impact on your scene

so again getting a little bit better

and if you notice that your

reflections are a little bit noisy

I'm not sure if you'll be

able to see this on YouTube

because of the compression

and the denoising that happens

but my reflections are very noisy so I can

fix that by increasing the sample per pixel down here

and set it to something like 10

and now again

this will have a performance impact but

it will clean things up nicely

so again

not the perfect solution because

you know

the reflection of the Chrome balls here are not

quite matching the

environment they are in

like we're not getting the same dark shadows

as we did with the lumen reflection right

again I'm gonna toggle it back and forth

just for demonstration purposes

does it with lumen reflections you'll see

the chrome ball here do seem to integrate

into the scene

much better

than they did with the ray traced reflections and

ray traced so

you know it doesn't quite integrate as well

but sometimes

you need this sometimes you need to get the better

crisper sharper reflections depending on your scene

so in true classic Unreal Engine fashion

you're going to have to pick the lesser of two

evils here you're going to have to pick and choose

which of these options

suits your specific use case the best

it's just something that you need to be aware of and

art direct accordingly

now with that out of the way

the last thing I want to touch base on is

the refraction here

you'll see the refraction here

it looks really really bad

and so this glass material is very simple

I just have a base color of 0 a specular of 1

a roughness of 0.05 and opacity set 2.1

and the refraction set to 1.5

1.5 because the IOR or the index of refraction of glass

is 1.5 then I have my blend mode set the translucent

and lighting mode set to surface forward shading

and that's it

hit apply I go way deeper into the

glass setting in this video right here

but obviously this glass doesn't look very good

so what do we need to do

what do we need to change

to get this to display properly

the same way it did in ue4

so again we're going to go now our post process volume

and in the search detailed panel of the post process

volume we're going to search for translucency

and we're going to change the type

from raster to ray tracing

and now this is actually behaving the way it should be

the same way it was in ue4

this is now possible

all because of the project setting that we changed

at the start of this video

so that's very very important

and it should go without saying

but I'm gonna say it again because

people seem to not realize this

if you're going to be using hardware ray tracing

you need to have a ray tracing capable graphics card

so ideally

an RTX GPU

I shouldn't have to say it but I'm going to say it

now the downside is

we seem to have lost the

shadows cast by the glass in UE5

in Unreal Engine 4.27 we did have

glass casting shadows so I'm not sure why we lost that

it kind of sucks because it was really cool to have

and we don't have any caustic

so we don't have any of that

refraction being cast

on the ground

the only way to get shadows and proper caustics

is with the path tracer

so I'm going to go ahead to the lit tab here

turn on the path tracing and you'll see now glass looks

way way way better

we're getting proper shadows

and caustics being refacted here

if I use this glass material on one of the tables here

you'll see it is actually casting its correct shadows

it's refracting light in a really pleasant way

it looks way better than

in regular lit mode like this just doesn't

this looks weird

real time

glass still does not look nearly as good as true

past trade glass

that's just a limitation of real time

engines at the moment

but at least now with raytray translucency

we can get proper refraction in our glass materials

and so that covers the main issues

I've seen a lot of people struggle with this week

if you want to learn more

about the Path Tracer or raytray Translucency

or Lumen or Nanite

you can watch all of my videos on the topic right here

so I hope you guys found this video helpful

and if you did

do consider subscribing

because I do have a whole bunch more

tutorials like this coming soon

so as always thank you so much for watching

and I'll see you next time