How to use Shadow Pass with incandescent objects in RedShift & Cinema4d

today i'm going to be showing you how to put shadows on to incandescent objects with redshift and cinema 4d so looking at this scene here what we've got in here is i've basically just got a taurus which is made of glass a foreground plate and on this foreground plate i actually have a texture of these hands i'm going to just open up our render here just so you can take a look so this is our current render so this foreground plate has a texture of these hands which are with an alpha so they're cut out and then behind them we have another uh back plate or another plate which has a texture on it if i switch off the fg here just so you can see that's what the background texture looks like in the foreground gets popped on here and as you can see it's just separated and then what i've got is i've just put this ring that goes around the hands like this now also what i have in here is if i switch these both off and i switch on my dome you'll notice i actually also have the same thing but as a back plate and now i've just got this as a back plate just to illustrate something to you um in when we are doing this process now i'm going to leave the back plate on for now what we're going to be doing is we're going to be doing a drop shadow here on this plate now there are several ways of doing this i'm going to show you two the first way that most people do is if they have a back plate like this for example they will create something called a shadow catcher shadow catcher is basically here's here it is i'm going to switch it on this is my shadow catcher as you'll notice it's pretty much the same size as the the background layer that i've got in here or plate so this shadow catcher by itself is just a polygon with no textures on it but if i come into redshift tags redshift object and pop this in here and inside the redshift tag itself we have a whole bunch of properties and the property i'm going to go with here is under matte i'm going to switch on the matte which basically makes it a matte object switch on enabled you'll notice it disappears because redshift is taking over now it understands we probably don't want to see it and i'm going to switch on this shadow option down here and you won't see anything just yet okay we have an area light in here i need to switch the area light on there we go now i've switched my area light on the area light by the way is this huge light over here which is literally just a standard area light it's casting down on this and it's casting a shadow now the shadow catcher itself if i look at it here i don't actually see anything i might see some green down here but if i look at the alpha over here you just don't see anything however if i was to come down here and say effects alpha and switch that on now you will start to see the shadows that will appear in white on the back plate so when i go back to my rgb here if i was to uh if i was to input this if you watch if i switch off the area light here you'll notice that there's no green here anymore the reason the green is showing up is because this is actually transparent so our shadow is not going to be very defined but if i just went into our material here for a second and i just brought my refraction down so it was a solid color would start to see maybe more of a shadow in here just ever so slightly but this is generally how people do their shadows because they'd render it out and then out of it they would take this alpha and this would cut the shadow up and then they would apply it in after effects and that's great the problem is is if i want to put it on an incandescent object that is not going to work so i'm just going to switch off this shadow catcher here for now and i'm going to come back to my uh object i'm just going to pump up the reflection here now i'm not going to make this a hundred percent down here on the refraction because if i make it 100 it's going to be very hard to see the shadows that we're working on i'm just going to bring it down to maybe something like 0.8 just to give us a little bit of non-transparency in here so that it'll be a bit solidified i'm going to switch on my background plate first there comes the background plate and then i'm going to switch on my foreground plate and there are the hands and as you can see it looks like these things are wrapping around the hands which is pretty cool now we need the shadow to drop on here now the way we do this is in the fg if i was to literally just take this tag and drop it on here you'll notice it first of all the hands become transparent that's because it's affecting the alpha so it's cutting those shadows out of the object and we're now seeing the back dome light if i switch the dome light off for example you'll see that it's actually just creating a silhouette but if we look at our alpha you'll see the shadows are in the alpha which is cool but again not really what i want i like to control my shadows so let's just take this off here right now the way that i usually do this is i actually make my own shadow passes which i'm going to show you over here under takes on the right hand side now if you're not familiar with takes this can be a bit complicated but this tutorial isn't about takes so i'm just going to make a take and not explain the entire theory but if we go to takes over here and click plus this is the add new take now when creating a new take everything you touch will only exist on that take layer okay so with my take there it is i'm just going to go back to my main layer first though and what i'm going to be doing is i know that i'm probably going to want to be changing a few things on the take side so i'm just going to come in here red shift tags and i'm just going to add a redshift object to my foreground my background and i'm going to make sure that my taurus has one as well there we go just the default tags that's all these are okay nothing special now i'm going to go back to the takes over here i'm going to dive into this take i'm just going to rename this take shadow now we've got everything in place what i'm going to do next i'm just going to come over here and just make sure we're using our default camera so you guys can see what we're doing okay cool right so here we've got our shadow pass now what i'm going to be doing is we need to actually i'm going to take this take and i'm just going to undock it here and the reason i'm undocking it is just because it's easier to work with if i have it down here in my main object menu up here i can just drag things in here which is what we're going to be doing if i look at this here what we want to do is we want a pass in after effects that we can bring in which is just going to be the shadows now these materials if we look at them they're actually incandescent materials if i open up the shader graph here you'll notice it's a material that is incandescent which means it's not going to take shadows so we have to basically create our own paths so here's how we do it i've got the shadow in place what i'm going to do is i'm going to come in here got my override tag switched on so whatever i do it's going to record it for the take and inside the matte option of this fg i'm going to switch this on switch this on to enabled switch on shadow switch on effects alpha because we wanted to be on the alpha for this for sure and i'm just going to go ahead and switch off show background because i don't want to show the background and on top of it we do not need our background because the background is not having any shadow effected on it in this case we just want the shadows to affect the hands so i'm just literally going to go to this background and we can just come in here go to the visibility click on override and switch off primary so that we don't see it anymore the reason i'm not switching it totally off is because i still want to show up in the refractions of the glass now the other thing is you'll notice i'm still seeing this background here and that's because the dome light is basically got um this image in it so what i'm going to do is i'm just going to switch on i'm going to go to the back plate here and i'm just going to make sure that the back plate is black there we go so now it's now this is what we're getting all right now i do not really want the color of this either if we look at the alpha you'll notice we're getting the shadow which is what i want but i don't want this in here however i do want it to cut out the shadow so the shadows don't go over it so to make sure that happens let's just go back to our redshift tag here on the foreground plate which is the one with the hands and i'm going to come over here where it says matte and in this option down here we actually have an option that says uh alpha and if i take this down to zero you'll notice that the shadow disappears okay but what we want to do is we'll remove the ring so if we go to the rings tag there it is switch on the matte switch on enabled and bring its alpha down to zero now we have the shadow and it's cutting it out if we go to the rgb it's just going to show black and that is exactly what we want to do now we're ready to go if we look at our main this is our main if i just highlight the main layer here there's the main if we look at the shadow we don't see anything but we know it's in the alpha so let's go ahead and render these out in our render settings under here we've got redshift set already 1280 720 in this case when we go to my save options there is no multi-pass that i'm using in here i'm not using aovs i'm just using a custom take so what we need to do in here is make sure that we've got this rendering somewhere i've already specified where this is going to render but what i have done here is i've put an underscore and i've put in here a token this token is this one here which is take which will basically apply this take name to the end of the file so we're just going to go to our output here everything's good and we're just going to tell it to render all takes so first what i'm going to do i'm just going to highlight both these takes so that they're nice and ready to go and we'll just render the first one so i'll just highlight it something to keep in mind here as well is make sure that you have alpha switched on in your settings here and i'm using a png or else the shadow won't come through we'll just render it there we go and i'll go to the second one here highlight it i'll render that as well and there we go now we can go over to after effects so here we are in after effects i'm just going to come in here and i'm literally just going to import these two so if we just find those two here they are i'm going to bring them in here and here we have the two the first one as you can see it says main which is the name of the take there it is the color layer the second one says shadow and if i drop that above here watch what happens on the hands we get a bit of shadow coming in and you might not see it just like this but if i duplicate this layer the shadow layer look at this now we start to see the shadows being applied here the shadows are very soft and the reason they are very soft is because of my shadow settings and also because i'm using a transparent material so the shadows don't really show up that well but what i will do is i would usually put all of these in a row like this pre-compose them and now if i want to i can actually duplicate that pre-comp and now i get even more shadow attributes going on here and obviously if i'd use the higher sample size i wouldn't have this grain going on there well and there you go cool well i hope you guys have enjoyed this tutorial and as always please support us on patreon and youtube and follow us on instagram thanks again guys

Channel: Single Frame Studios

Views: 1,043

Keywords: redshift, cinema4d, c4d, aftereffects, adobe, shadows, takes, 3D, animation, VFX, incandescent, shadow matte

Id: p22bxEViqTQ

Length: 11min 9sec (669 seconds)

Published: Mon Aug 03 2020