Architectural Visualization with C4D and Octane: Creating Dielectric Materials

Photo of Brandon Clements

Instructor Brandon Clements

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  • Duration: 11:39
  • Views: 2689
  • Made with Release: 18
  • Works with Release: 18 and greater

This video explains proper creation and ideas behind physically based dielectric materials.

Note: Due to the file-size of the project files. It has been split up for easier downloading.
Project File without tex can be found here: Using Substance Plugin
Tex, Part 1 can be found attached to this tutorial.
Tex, Part 2 can be found here: Creating Conductors In Octane and C4D

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Transcript

Hello again, and welcome back. In these next two videos, we're going to be talking about how to create dielectrics and conductors inside of Cinema 4D in Octane So, in this first video, we're just going to be talking about dielectrics. Dielectrics are essentially anything that is not a conductor, anything that exhibits some traits like may be the bricks on a fireplace, we have the shiny hardwood floors and then we also have this kind of faux leather that's going to be on this chair right here. So, that's what we're going to focus on, is this blue chair. And if we come into this other scene that I have, we can see that we just have the actual mesh inside of a room, and this is basically the same lighting setup. We're just going to focus on the chair and making this look as good as possible. And I have a camera in here as well, which is set up almost the exact same way as the last scene. So, this allows me to just focus on one material type, and make that look as good as possible. And the great thing about PBR Rendering is that if it looks really good in this scene, it's going to look great with our other objects in our other scene. Okay, so let's go ahead and create a shader, octane material. And the material type that we're going to be using from these different models is the glossy type. Just as an overview, diffuse is something that has incredible irregularities on the surface, and we don't really see the reflection so much on the surface. So, this is something like a clay vase maybe, or sand, something that's incredibly diffuse. Glossy is going to be the one that we're going to focus on. And that's going to allow us to have a nice, shiny reflection if we need to or you can increase the roughness to make it irregular. So, what I'm going to do is I have a texture map that I'm going to load in. So I'm going to go to C4D Octane, and image texture, and I'm going to navigate to that texture. And all theses textures that I'm going to be loading up have been created inside a Substance Designer. So as an overview, I just would like to talk about what makes this texture map so important to this chair asset. Unfortunately, we won't be going into Substance Designer in this course. It would just take a little bit too long to do that in all one series. Okay, so, what I have here is just kind of my base color in the diffuse and this is going to be the overall color and we also have some variation across the surface, so that we have some different details in other places. As just a general note, adding variation to your texture maps inside of your diffuse, is going to give you a little bit more realism just because surfaces in the real world are not perfect and we don't have the same color going across an object. We have gradations of tone. We have dirt, wear, things like that that are going to help it make it look a lot better. Okay. So, down here, just for the type, we're going to have it set to Normal. Normal type is going to be RGB, so we're going to load up any RGB maps with this Normal type. Float is going to be for like our roughness maybe our specular and our bump maps are going to be float. Just because we want to use gray scale values, we don't really care about RGB as much, we just want use those black and white values and work on the float. The alpha type is used when you have RGB and an alpha channel included. So your corresponding image format can be used for transparency. We don't have to gamma-correct this since this is an SRGB image. We don't need to set the gamma to 1. Octane is going to be able to take care of this for us. So, this is what we need to just go ahead and work with texture maps. If we come down to roughness, I need to also load up a roughness map, so I will do so right now. So, the roughness map is going to create some variation of irregularity across the surface. So at the black end of the spectrum, at the very dark end of the spectrum, we're going to have a very shiny smooth surface. And as we increase in values, once we approach white, we're going to have a very irregular bumpy surface. And that's going to create a rough reflection across the surface of our material. Okay, so let's go ahead and load up our Normal. And let's go to our index, and we're going to change this to a...index is familiar to dielectrics and plastics, so let's use 1.5. And we're going to take a look at this very soon. What this number actually means. But first, lets go ahead and see what this looks like. We're going to open the live viewer. We're going to drag this material onto our object. Go ahead and select it, right here is our chair. Just drag and drop that on there. Make sure it is set to UV mapping, which it is. And we're going to load it. And this will take just a moment. And we can see in the newer versions of Octane, we can see what takes the longest time, and exporting materials in the geometry is being cached on to the GPUs. All right. So, here is what it looks like once it's updated, and it's in there. So, there is one thing that I want to point out. If you go into your roughness map which I mentioned could be a float value, you know, a float value that could actually be here from 0 to 1. We're just using this as a texture map, so we don't need RGB data. Now, keep an eye down here on my used vram. If we go into here, and we change this down to float, we're going to conserve a considerable amount of vram, just from using this float value here for our texture map. So, as you can see from the example, when you have a lot of textures, displacement and geometry that's going to fill up your vram very quickly. So now let's take a look at index, this index value, and let's talk about this index value. So, there is a great Website that you can go to called refractiveindex.info. You know, you just make this just a little bit smaller. What this Website is going to allow us to do is look up different types of materials that are in the real world, and get this n value which stands for index. This is the scientific value for n=.02 in this instance, but we're going to actually go to this three tab right here, so this is for a studio artist, and we're going to go down to plastics. Before, we were looking at metals, and we're going to allow this to load up the plastics. Okay, so as I cycle through these, we can see it goes from 1.4 to 1.5. In some cases, we can even reach up to 1.6 and 1.8. All right. So, we can test those in our scenes, see how they look. I'm going to leave it at 1.5. Now, in the next video, we're going to be taking in more in-depth look about metals. And they're a little more complicated than say, our just plastics here. All right. So, this is just scientific data that we have been able to record from the real world. Okay. So, we're almost done with creating this plastic look for our faux leather. So, what I would like to talk about right now is correlation between the specular channel and the index. So, the specular is basically asking how shiny is the surface. And that can be pretty tricky when you're working with index. And a lot of times, this is something that I'll just have to gauge just for artistic reasons. Right now, we can see we have a very specular, a very shiny kind of surface. And as I pull this down, we're going to see this effect diminish in the reflection. For our purposes, I'm going to go ahead and just leave it at .8. So, we take a look at our roughness channel. We have a variation of roughness going across the surface from these dark areas being very shiny, to the bright areas being very rough. Now, one thing that I would like to add to our shader here, is the phenomenon that happens a lot with the Fresnel effect which, of course, comes from this index number. But this index number is not allowing us to have on the glancing angle, very shiny surfaces. Okay. So, this is being controlled by this actual map. Now, what we can do is just add a multiply node, and we'll go ahead and drag that to the bottom here. I like to use this texture one input for a Falloff map. So, if we use the Falloff map, what this is going to allow us to do is actually have on the outside edge a value that's going to allow the surface to be very shiny and at the facing angle, something that looks very rough. Now...right now, just from using this a lot, the outer edge is going to be white and then the portion here at the facing angle is going to be dark. So, what we need to do is just go ahead and use an invert node. And I'm going to actually pull this factor down to around 1.8. And if we visualize this on a sphere, just very quickly, drop a sphere into our viewport, I want to go ahead and just illustrate what that is doing, just to make it clear. So, we'll just pull this up, and move this into view. And then we can grab our Invert Node, copy it and this is the invert of our Falloff map. We'll go into the test shader, and we can just paste this. And I like to have just a test shader handy, just so I can perform little experiments like this and show exactly what's happening. Okay. So, we can see that the edges are very dark and from the facing angle, we still have this bright value of 1. So, let's get a little better look at our material on our chair. One last thing that I would like to do to our chair is just come into the roughness channel and go into our texture map. I'm going to adjust the gamma to 1.25, and what that's going to allow us to do is push this texture map a little brighter. Okay, so we're going to pull this into the brighter end of the spectrum to get this to not be so shiny and so smooth. I'd like to show you another way to do that with your texture maps. It's pretty awesome to have this capability. If we go to C4D Octane, then we go to clamp texture, once that loads in, what this clamp texture is going to allow us to do is add the minimum amount and the maximum float values in here. So, I can rope this off and say, "I don't want this to be any shinier than .3, and I' would like the maximum to not be any greater than .6." And I also like to use this Render region just to kind of focus on one area and let my computer just render that area. Okay. So, you can see from the texture map that I have, we got a little bit wear and tear and some scratches. Give this chair just a little bit more character. All right. So, that will conclude this video. In the next video, we're actually going to look at creating some physically correct metallic surface for the chrome legs. So, thanks again, guys, and we'll see you in the next video.
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