Hey what's up guys I'm back with another video and in today's video wait a second
I have to move this away from here in this video I'll show you a simple
solution to a problem with emissive lights inside mobian I never noticed
this myself until a user named Kailash message me on Instagram saying quick
question how do you use it alight in lumen for curved designs we can use
emissive material but if you can see them they won't render right do you find
any solution for this matter he means this type of designs which have hidden
lights facing the wall so I went further to distribute this issue and found out
it if the plane in which you have the emissive material is not facing directly
the render camera then it won't render any light so in this video I'll show you
how you can go from this to this with a very simple technique so let's get
started so I have here my scene inside mami on and what I'm going to do oh by
the way I just want my Lumiere course it's an in-depth course in which I'm
showing you all the techniques I use to achieve high quality renders with lumen
I'll leave a link in the description below this video I have here already the
emissive material to the back as you can see so it should give some light you
know the light would hit the wall and create this halo effect like we seen in
those photos but if I go and take a rendered let's see
you see no light is coming from behind these panels so we have nothing so we
could fix this several ways one could be we could add some spotlight to the back
and try to match it the best possible but my experience is not easy to do that
another way could be an area area light this area light is easier to do but I
don't think is the ideal solution but I will still show you how this would look
so models like this and like this and then I will just decrease this more or
less like so like a square shape and increase this make it yellowish and I'll
go here and side okay and move it down okay crystal brightness so this could be
a solution and it would look more or less like this let's see so you see it
now like this we have this effect on the back cover of it but first you will need
to do this to every shape and second if you would have something like let's say
like this effects here let me open this so like this effect you know with these
shapes or so this one is better to see or this so what would mean is that you
will have to go and duplicate each light and it make it like very small and
duplicate duplicate duplicate I don't think it's a nice way to work so that's
why we have the emissive material right so what I'd like to do is go here to the
back and I will just duplicate this material not duplicate I will copy it
and paste here on the front okay so now it's facing the
camera the missing material and I'll just take any render so you see now we
have on each panel we have this backlight hitting the wall so what we
need to do now we need to have a mask so it is therefore for us to select this
all these panels because we are going to edit this now in Photoshop okay so what
we can do is go again to render I'm just going to select this one material ID map
okay and let me just render it again
okay now we have our material D and I'm going to go to photoshop and inside
Photoshop I have the materiality the second render with the emissive lights
facing the camera and the ones without so what I'm going to do is that I'm
gonna copy this one and paste here then I'm going to copy the material ID I'm
gonna do the same thing and also let me just quickly crop this out like this
crop okay so now what I want to do I want to just
keep this part here because if you see on those images let's see see you have
the light on the back and then we have this part is not lit so what we'll do
here Photoshop will use this material ID to create our mask so just with a quick
selection tool and with the inner edge selected I'll just with the mouse drag
drag around like this okay let me just see if needs any refinements here you
can just click alt and remove if it's not very well so you can just use the
lasso tool and just make it more or less so now what we need to do go to feather
one pixel this you like this layer and here just press the mask on the bottom
okay now we are almost done another thing we need to do is to control click
the mask so it will create a selection for us go to select and modify contract
let's say five pixels we also want to feather this so let's feather five
pixels and now let's start erasing a little bit on on this area so we're
gonna select this larger brush and possibly about 25
and we're going to invert it okay and now and I just start erasing this areas
so it creates a little bit of this glow around the shape so it's not too too
perfect okay and this is the before and after so then after this you can just
create a new layer and image apply image and from here you can just go and start
making all your edits color correct color correction all of this so and this
is my final result so this lumen has this limitation this
is a quick way an easy way to achieve the same result as you saw in those
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