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Getting good specular maps with the skin shader requires some extra work. The shader isn't really made for creating a variety of specular types on a single shader. For this we're going to have to go back to the values that we wrote down back in Chapter 8 when we first set up the skin shader. Then we'll use those values to manipulate the spec map that we made in Photoshop. So let's do a render of the Dewhopper as he is right now. I am going to click in the Perspective viewport and I am just going to hit Spacebar so we can see it nice and big and let's just zoom in so that we can get it really tight on this, so we can see what the renders are doing. All right! Go ahead and hit Render.
Okay, so we've got our finished render now. The problem that we are running into is that the entire model has the exact same shininess. The inside of the mouth, the boney plates, the leathery skin, they're all just kind of this medium amount of shiny. And what we really need to do is to control it with the map so that the leathery skin is very dull, may be slightly shiny if at all. The boney plates are kind of a medium shiny and we need to get the inside of the mouth to be very shiny. We are going to be able to make this happen with something called a remapValue node.
The remapValue node is going to take a specularity map and break it up into three different channels that we can control independently. So let's save this render so that we can compare it to the results later on. I am going to close the Render View and let's go to our Hypershade. So, I'll just hit Spacebar and we'll bring that back. All right! Let's look at everything that's going into the skin shader right now. So in our Materials, let's select the skin shader and now click this button up here and it's going to show us everything that's going into the skin shader.
So here is the normal map that we plugged in, the color, the ambient occlusion is up here. Now let's get our specular map into the picture. Open up the Textures tab and we've got the spec map right here. I am just going to middle mouse drag it into the work area. It's not connected to the shader yet. Now we are going to create some remapValue nodes. Those can be found over here on the Create side of the Hypershade. You might have to scroll until you find them. Here it is right here, the Remap Value node and just click that three times.
And actually, I want to scoot this over so we have more room to work with. I am just going to slide this over and let me select the specular map and I am just going to move it over here to this side. Now remember, there were three different specularity channels that we need to control. One of them was Overall Weight, the second one was Primary Weight, and the third one was Primary Shininess. So let's name all of these remapValue nodes to correspond to the channel that we are going to control. So the first one, let's rename this one to overall.
The second one, let's name it primaryWeight and the third one shininess. Now let's take a look at the attributes of this node. I am going to scoot this thing down so I can see more of the Attribute Editor. So the remapValue node takes a grayscale image like our specular map and it maps it along this value. So what you get is the black pixels down here at the bottom, get converted into a value of 0.
Our white pixels up here at the top get converted to a value of 1 and there is a linear gradation between the two. And what we're going to do is change how the map is interpreted by putting in different values so that we get a different output. So you could slide this up or down. You can even insert new values in between, so you can change the amount of gradation. I am just going to undo that; you can actually delete these by clicking the X down here. Okay, so now let's connect the specular texture map that we created into all these remapValue nodes.
Click with the middle-mouse button and drag from the texture map to one of the remapValue nodes and now click Default. What we need to do is to pick the outAlpha from the texture map and plug it in to the input value and just close it. Do the same thing for the other two. Middle mouse drag over > Default > outAlpha > inputValue and close, and just one more time; Default > outAlpha > inputValue.
Now we need to connect the remapValue nodes into the skin shader. So select the skin shader and we're here in the Specularity section of it. So we've got the Overall Weight here. So we want to take the overall (remapValue) node, middle-mouse drag it over to Overall Weight. Here we've got the Primary Weight, remapValue node, going to middle mouse, drag this over to Primary Weight here and then Primary Shininess, same thing. As it is now, we haven't changed any of the graphs in the remapValue nodes.
So the result we would see in a render is no different than if we simply plugged this specular map directly into the skin shader. Let's just do a quick render to see what that would look like. Okay, let's save this image and compare the two. So it's looking a lot better, but we still need to be able to control the values more specifically. For example, the inside of the mouth isn't nearly shiny enough. By creating remapValue nodes, we can have much finer control over how our map is going to interpret it in the renders.
It also will make it easier to adjust settings because you can tweak some sliders rather than having to go back to Photoshop and edit maps there. In the next movie, we're actually going to be making those modifications to the remapValue node in order to bring out more specularity in certain areas.
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