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Skill Level Intermediate
- [Instructor] When you're working with 3D renders in After Effects, there are few ways to make the comp process more flexible and faster. One of my favorite methods is to use the Open EXR format to save multiple passes and then combine them later in After Effects. This can save you ton of time in post and can help you out direct and tweak the result without the need to re-render it in 3D. So, let me show you how to set it up inside Cinema 4D and then how to make the most out of this format by using a new feature in the latest version of After Effects. So this is what we are going to create, but for now, I'm just going to close this footage window as well as say goodbye to this file, and switch over to Cinema 4D, which in my machine is running in the background. Now, before I continue, I should say that this project is part of a soccer World Cup package that was created by Pro Mathias Post House in Tel Aviv. If you like you can check their amazing work at promots.tv. Anyhow, what we are seeing here is three babushka dolls, one for Japan, the other one for Australia and the other one for Mexico. Now to save some time, I'm going to just demonstrate with this steel frame render. But of course, these can also be an animated sequence. So to set up the passes, in Cinema 4D, we need to click on the render settings icon. Over here, the first thing that I want to make sure is that I'm rendering to the desired size, in my case, full HD, then I'm going to enable the multi-pass render. Now for the multi-pass, I can use these list and add a couple of passes. So for example, let's choose the RGB image, although this is usually an unnecessary step because cinema will render an RGB image anyhow. I'm also going to click again here and I'm going to select ambient occlusion as well as the depth pass. I'm also going to add the diffuse, then click again on this list and add the shadow pass. And then I'm going to add three instances of the object buffer. Now, I'm just going to edit over here, this will be group number one and then I'm going to return and add another one, set it to group number two and then another one, this will be group number three. For a moment, I'm just going to take this window outside of the screen and show you that here inside the main interface. I've already applied the compositing tag, which in the recent version of Cinema 4D, you can find under the render tags, so this is it and I've set each one of the different doors here to be a different object buffer. So the Japan door is object buffer number one, the Australia one is number two and the one with the Mexican flag is set to a buffer number three. And this way when I'm using it over here, by setting three different object buffers I will get the transparency or the alpha channel for each one of those individual object. Alright, this is all we need to set over here. Now I'm going to click on the Save option and I'm going to make sure that under format it is set to open EXR. However, I don't need to save a regular image, I'm just want to make sure that under multi-pass image, I'm going to take this which in my case is already been set, I'm just going to place it over here the desktop and say save. Make sure the format once again is set to open the EXR, 32 bit per channel. And this is very important one multi layer file should be checked. Okay, it looks that everything is set to be rendered. So I can close this dialog and I can click over here where it says render to picture viewer. And this is going to start rendering this frame. And while it's rendering it, we can go to the Layer menu. And over here, we can see that it's actually rendering different passes the same way that I just defined. And if you want to take a look at them, each one individually here inside the picture viewer, we can move to single pass, click on one of them and just verify that indeed, we have all the desired information that we want to bring into After Effects. Right, so this is all we need to do in this case, once again, I'm demonstrating it using a single file. But if you are rendering it to a sequence of animation, the process is similar. Alright, so let's bring back After effects to the foreground. And here inside After Effects, I'll double click on a great portion inside the project planner. And this, of course, will invoke the input dialog and I'm going to navigate to the desktop where I save the babushka doll EXR. On the new feature assuming that you're using After Effects 2020 or above, is that you can create a composition. So make sure that this is checked, when you are bringing these open EXR. When you select this option and click Open, you'll get another dialog. Now you can choose if you want to create a composition out of it, as well as maybe pre compose the layer or use a contact sheet. So I'm going to leave out the pre compose option. But I will create a contact sheet and show you immediately what it will do. So let's click OK. And now that will click on the comp over here which says Babushka contact sheet and we can see that we have a split screen with all the different passes just to make sure that we indeed got everything that we wanted out of this 3D package. In my case, I'm happy with the result. So let's double click on the babushka column and over here we can see that we have separated all the passes to individual layers. Now note that we also got text file, if I'll enable it, this is automatically being set to a guide layer. And it will give you some information about whatever you just rendered. So in my case, it is redundant, I'm just going to select and delete it. And before we are going to move on, we need to set the project bit depth as well as manage the colors. So I'll click over here it says eight BBC and this will take me to the project settings. I'll change the depth to 32 bits per channel in parentheses float and I will select a working space. So in my case, I'm going to choose pro photo RGB but you can go with whatever you like. This is the most important thing you must click on Linearize Working Space to match the colors between After Effects and Cinema 4D. All right, now that we have all the technical stuff out of the way, let's take a look at the result. So we have this RGB layer, once again, I'm going to switch it off. In fact, I'm going To brush down on the eyeball and switch off all the layers. So we're actually going to start with the background here, I'm going to turn it on. And this is our layer, of course and as you can see there is an fx icon, which means that automatically when we did this move After Effects applied to the extractor effect, which you can find if you want under the 3D channel category over here and this extractor effect is basically going to read all the different passes that were defined inside your 3D application. Alright, so let's see what we can do with it. I'm going to start with the shadow pass. I'm going to enable it and as we can see, all of the channels are set to the shadow but we need to make sure that the blending mode is correct. In this case, it doesn't do the work for us. So let's just choose the appropriate blending mode, in this case multiply. This way we can see the contribution of the shadows and of course, we can make them stronger or lighter. So just to illustrate how we can do such a thing, I'm actually going to use the ambient occlusion pass. So let me just expand this so we can read what it says. Let's switch it on and bring it on top of all the other layers. So this is just the ambient occlusion. Once again, I'm going to set it to use the multiply blending mode. And in this case, since I want to darken these ambient occlusion, I'll go to Effect color correction, apply the levers effect, I'll take the input black and just crush it until the beginning of this histogram. And once again, we can switch it on and off to see the contribution. And now because we did this lever, we can say that the result that we got is a little bit grainy but here at the post stage, we can go to the blur and sharpen category at the fast box blur effect, repeat the edge pixels and let's set it to let's say a value of 10 or maybe eight, just to soften those shadows. So once again, this is the before and after, of course, we can do the same for the other layers. So here are the three object buffers layer that we have, I'm going to shift select all of them, enable the visibility switch and then bring them just between the ambient and the shadow pass. This means that I can just select each one of them individually, for example, this is the Australian flag and apply any effect that I like. So let's go under color correction once again, just to illustrate the flexibility that you have over here. Apply the hue and saturation. Maybe, let's just saturate this just a bit more because it is right in front of us. Alright, we have two more passes here that we can use. So this is the diffuse one, we can enable it. Once again, we can change the order, so let's just drag it above the object buffers. Then press T to show the opacity and reduce it to, let's say 20%. And now, last but not least, we also have a depth map. And this is something that you can use with a compound blare effect to determine the amount of blare in your shot. Now know that currently, the depth is set to the alpha channel. A good idea is to use one of the channel effects, in this case, I'm going to choose the shift channel effect. And then I'm going to take all of the other channels from the alpha information. And this means that now I'm going to just solo this effect, it's actually going to show us a black and white representation of the depth in our scene. And of course, if there is a need, we can use under color correction and another levers effect and just close the histogram so it will be even more evident in terms of the difference but since we are working with a 32 bit image and it's not really necessary. And to illustrate how this works, I'm going to switch off the visibility for this layer, make sure nothing is selected and then go under layer new and create a new adjustment layer, to this adjustment layer, I'm going to add the camera lens blur effect, which is a built in effect that can use a blur map. And our blur map should be the depth layer that we've imported from 3D and we want to take all the effects and masks. So now if I'm going to change the blur radius, we can get a sense of how this is working. And of course, we can also change the focal length to determine which one is in focus. And so this is it. So to summarize, if you want more control in the post stage render to the open EXR format, from the 3D application that you are using, just take under consideration that those EXR files are quite large. So make sure you have enough space as well as quick hard drives to be able to pull all of these data. But even with this limitation, this method offer much more creativity control at the post stage without the need to re-render the file back in 3D