Transforming Robot Production Pipeline Volume 5: Robot Texturing

In this lesson we'll learn how some of the channels, that were previously used for our robot, can be repurposed to create our specular map. All right, let's say that we're done painting the textures for our robot. And we're ready to begin thinking about sending our maps over to Kyle for rendering. Now before we do, there's one other element I want to consider. And that's the specular information. So let's go ahead and beef that up here. We'll just jump over to the lighting shader module, and crank up that specular gain slider, just so we can see what's going with that really clearly. Now if I zoom in here kind of on his torso, we can see that all the services in their current state, are reflecting light equally. Now we've painted in some elements on our robot here that would cause that not to be the case. Things like rust and dirt are going to break up that reflection. And they're not going to reflect that light the same as areas that don't have that information. So let's think about maybe some ways that we can use some of our existing channels to help bring that reflection down in those areas. So I'll go ahead and switch over to my default shader for right now. And if we look at our channels, I've gone ahead and duplicated some of the channels here we're going to use. I've duplicated both our dirt broad mask, and our dirt fine mask, as well as our rust channel. Now if you look here at the first two copies-- dirt broad and dirt fine-- you'll see that I've actually inverted those channels. Now the reason being is because here we were painting in white to reveal the dirt. And now we want those areas that were white to be black, so that they hide that reflection. So that's why these two channels have both been inverted. Now we're also going to utilize the scuffs mask channel. But we're going to utilize it in its current state. Because these are areas where the paint's been scuffed off the robot. And I want those to be a little more reflective. I see that to be kind of an area where raw metal has been revealed. So the last channel we're going to use is this rust copy. Now the rust copy's a little bit different here in that this channel has transparency, and it has color. So we're going to get rid of both of those. Let's go ahead and handle the color first. And in order to get rid of the color on this channel, let's just go ahead and run a luminosity filter, right here. And what this filter is going to do is it's going to go ahead and discard all color information, and leave us with only the luminosity values here. So we'll go ahead an apply that. And now we can see that we're now just dealing with black and white information here. Now I'm going to go ahead and invert these values really quickly here, and I'll show you why here in just a moment. It may seem correct in its current state with the rust being this black color, but let's go ahead and just invert that for right now. Go ahead and run the invert filter here on the entire channel. All right. So the next issue I'm going to address is the transparency. Now the transparency is created because we have an RGBA channel. And if we right click and choose convert channel, we can actually switch this over to just a normal RGB channel. Now when we do this, what's going to happen is it's going to fill all the transparency with black. So that's why I went ahead and inverted that, so that black will match up with sort of this black halo around our rust spots. All right there we go. So you can see here now our-- basically our channel has exactly opposite the information we need. And all we need to do to resolve this is invert the channel one last time. So we'll again run the invert filter here. You can see, based on the preview, we're going to get almost an entirely white channel with just a few areas that are going to be masked down here. Now if we really wanted to be meticulous about this, some of these areas around our rust have sort of this dark gray hue to them. There's kind of this halo around them. We could actually come in and run a contrast filter on this, if we want to kind of get rid of those areas. We'll come in here and pull that up. And maybe just adjust the amount slider, just a little bit. So we can get rid of some of those in between values. Maybe something like that-- All right great. So now we have all of our channels ready. Let's go ahead and jump over to our shaders. And what I'm going to go ahead and do is create sort of a dummy shader here. We'll just go ahead and create a new shader. And let's double click on it and just call this one spec. Now to start with, with this base diffuse shader module down here, I'm going to want to go ahead and fill that with kind of a 50% gray. And I'll show you why here in just a moment. So in order to do that I'll create a new channel. And let's just call this one base, there we go. Only need it to be a scaler channel, and we'll leave this at the default 50% gray. There we go. I'm going to go ahead and plug this in as my base diffuse texture. There we go. And now we can begin adding in shader modules for each of those channels we need. Now I'm going to go ahead and first add in the scuff's. And I'm going to add that as a diffuse blend. Go ahead and set that to the correct scuffs mask channel here. Go ahead and add another one in-- again, diffuse blend. And this one's going to be for the dirt broad. There we go. And let's go ahead and add yet another one. This one's for dirt fine. And we'll add one more here for the rest. All right, there we go. Now obviously in their current state, those shader modules aren't going to do us much good. So let me go ahead and hide those four that we just created. And we'll start here with the base diffuse. Now the reason I went with the 50% grey here, is because we can go both darker and lighter from here. Now thinking about how the specularity is applied to those surfaces, I want the yellow paint where there's no dirt, where there's no rust, or scratches. I want that to be kind of my 50%, kind of my medium. And we want to be able to go both shinier than that, and less shiny than that. So based on that, let's go ahead and first address the scuffs here. You can see if I turn those on, they are completely hiding that 50% gray. We could either set this over to something like maybe lighten. And you can see we're starting to get a little bit of those white spots in. I'm actually going to go and set this to maybe screen. And that's going to allow me to see all of those white areas kind of screened on to that 50% gray. So with that one in place, we're ready to go ahead and come in and address the dirt channels. Now for the blend modes on these, let's go ahead and set these to-- actually let's turn them on first here. Let's turn this one on, and then you can see here again, completely hiding everything underneath. So let's go ahead and change this to something like multiply. There we go, that's going to give us some nice dark values in there, Where the initial dirt pass is being hidden. So with that in place, let's go ahead and set the other dirt shader module to multiply, and reveal it. And also do the same thing for our rust. So all three of those are all set to multiply. Now this is kind of a preview, in the middle of our screen, of what this new channel is going to look like. That we're going to use to basically mask the specularity. So now to tell MARI that we want to combine all of these channels into one channel, what we need to do is bake this down. We're going to bake our shader by right clicking on it over here, choosing bake shader. We'll make sure the appropriate shader is selected on the left here. And let's go ahead and tell MARI we want to diffuse. Now I know we're baking out specular information, but I really just want to diffuse for right now. And I'll go and set that to bleed, so we bleed the edges of those shells. I'll go ahead and say all visible patches here. We'll just leave all the rest of the settings alone. And when MARI done baking down our shader, we can see here that if we jump over to the channels palette, that we have a new diffuse channel here with all that information combined on to it, which is exactly what we wanted. So let me just rename this. I'll just call this something like spec baked. And now we can add this in to a new shader module for our robot shader. So with that said, let's go ahead and add a specular gain shader module. I'm going to make sure that's right underneath my lighting module, just so there's nothing covering that up. Then I'm going to go ahead and set the gain texture to that spec baked channel. All right, now we can go ahead and crank this up even further here. And you can kind of see how some of these areas where there's no dirt-- maybe right here on his head, or right over here-- those are quite a bit more shiny than some of these areas that have dirt and rust on them here. So we're doing a really good job of masking out the areas that would not reflect light. Now thinking about kind of the initial materials that this robot would be made out of, I hadn't envisioned that everything would have the same initial specularity. So for example, these yellow areas wouldn't be quite as shiny as, say, these areas right here that are more of a silver. I kind of envision these areas to be kind of a chrome. So those would have more of a higher reflectivity than the yellow paint, or these shoulder pieces. So we're going to need to jump over again to our default shader module. And we're going to need to make some changes to this spec baked channel. So I tell you what, let's go ahead and do that in the next lesson.