Procedural Texturing in Maya and V-Ray

In this lesson we're going to tweak the VRayFur to get the look that we're going for the pili. So this is where we left off in the previous lesson, and this is the render that we did. So now let's go ahead and start tweaking the VRayFur. So to tweak the VRayFur, just select the hair and now open up the Attribute Editor. And let's go over these and tweak them. So here we can tweak the lengths of the hair, so I'll just zoom in. And for this, for the cell, I'm going for a really, really short kind of hair, so something around 0.1. Again, feel free, you can you make the pili, or the hairy tentacles, as big as you want. But for the look that I'm going for I'm just going for those small, hairy looking surface on the cell membrane. For the thickness I'm going for really small. I'm not going to add gravity. If you look at this, I'm just going to make this, for this example, just to make it clear for you guys so you can see it, gravity will make these guys look down. And I just turn off gravity and go up to minus, something like this. If you go up to 0, you'll see these guys will stand up. So I think something around, can leave it to 3 if you want. Something around this is good. For the bend, this will add some bend to the hair. You can leave it straight, but I will add some bend to it, just to make it look more natural. Something around 0.5 is good. Taper, we won't need taper, because these are going to be really thin. So we don't have any large thickness to it. This will just add some taper to the ends of each hair. For the sides, this is the sides of each. So think of each hair as a cylinder, and it's three sides of a cylinder, and the knots are all the parts that make the-- it's the vertical subdivision on how many subdivisions does this have. So this is good if you want to add a lot of bend to it. So I think 0.5 is good. Now we're going to play around with the direction, with the variances. And this will add-- just that we can add a more natural look and we have each hair looking into other, so we don't have this straight, artificial look to it. Just something around 5, 5.6, around that. Length variance again, just so we get a variety in the lengths of the hair, something around 0.7. Again, feel free to play around with these settings to get the look that you're going for. Thick variance, I'm going to leave that, because I said, these are going to be really, really, really, really thin. So it's 0.010. They're going to be really small, because we need them just to make a really subtle effect. Now, for the gravity I'm going to tone these, just so we can get a more interesting look. So we have a couple looking down, the gravity effecting them more, a couple less affected by the gravity, and so on. And for distribution, on each face I'm going to add three. I think it's enough. And let's go ahead and do a test render and let's see how this looks. So as I said, I'm going for a really subtle effect. So here you can see the hairy surface of the cell membrane on top of the pili mesh. But if you look close to this, you're going to see on top here we have more hair than on the side, and the same thing happens on the bottom. And this is because the distribution of the hair happens per face. And we added this to a sphere. And usually spheres, if we go ahead and press Shift I to isolate the sphere, you're going to see, usually spheres have a lot of faces when it comes to the poles. And this is why we're getting more distribution here and we have more hair on the top and bottom poles of the sphere. So how do we go about fixing this? We can try to create a sphere with no poles, maybe a subdivision sphere, but that means recreating the sphere. It might not be a problem to recreate the sphere, because by the end of the day it's just a simple primitive, but think if you have a really complex shape and it's not that easy to go back and just remake it to work on it. But there is a solution for this. So the first thing to do is to go back and press Shift I again, just so we can get out of the isolation mode. You can do that, the same thing. You can select the sphere. It's the same thing when you go to show Isolate View Selected, but these shortcuts with the Shift I. Now, to fix this we just have to do a couple of small steps. So we go to Window, Outliner. Again, go to Show All. And here we're going to have the cell and we have the pili mesh. So what I'm going to do is I'm going to select the pili mesh and the cell membrane and group these by hitting Command G, or Control G if you're on a PC. And what I'm going to do is I'm going to go into my rendering camera and go to Panels, Perspective Render Camera, and I'm going to rotate the group, not each one, so both of them move. And I'm going to make the poles to face the camera. Now if we go ahead and do a test render, I'm going to close up the outliner, keep this, and do a render. So this is what we get. So why did we go ahead and rotate the spheres? We did that because this way, if we look into perspective, if we look to the side, I'm just going to show edges. If you look to this side you're going to see that this here, we have an even distribution of faces, rather, on the poles. But on the poles we do have a lot of hairs because we do have a lot of faces. But when we rotated this we're facing a new problem. Because the poles, now, are facing the camera, we're getting some hairy splotches facing the camera. Although the pili shader, to look into the hypershade, the pili does have a pili sample linked to the pili opacity with a facing ratio. But no matter how low you put the opacity, you're still going to get those splotches in the middle. But there is a solution for that. So to fix that what we're going to do is we're going to use a mask. And to create a mask we're just going to have to create a simple ramp. Let's go ahead over into the hypershade, and I'm going to go into the-- just close up the attributes, press Space to expand the work area, and under 2D Textures I'm just going to go ahead and clear the graph. And the 2D Textures, go ahead and select a ramp. For this ramp I'm going to keep it really simple. It's going to have just two colors. Again, this is a mask, and for mask and bumps, I think you're used to it now. You're using black and white colors. So this is going to be black, this is going to be white, and this is going to be black. And I'm going to go ahead and link this into Maya Lambert. I'm going to drag and drop this into the default. Why am I doing this? Well, we're doing this just to visualize easier where we want the hair to grow, and where we want the hair to be visible and where do we want the hair to be invisible so we can take out the guesswork. The best way to do this is to go ahead and just add the mask that we're going to use to mask the hair on a Lambert, and then just right click Assign Material To Selection. If we go ahead and press Select Texture or press 6-- and just remove edges-- we're going to see the mask on the sphere. And this makes it easier for us to visualize and see what to tweak to achieve the look that we're going for. And now we see that the ramp is repeating itself, although I added only one line. To fix, this, just select the pili mesh, so make sure it's the pili mesh, I have pili mesh. Under Edit UVs select UV Texture Editor. I'm going to resize this a bit. Now zoom out, and you're going to see that this is really big. And this is because we converted from nurbs into a poly. And now just right click Select UVs, go ahead and select all the UVs, just press R on your keyboard, and just resize these so they fit into the texture area. You can resize them a bit and make them fit into the texture area, just so we get-- Now, if we close this and we look, we can see that now we have one line. But we want this line to be along these faces, not along the poles. If we're doing it along the poles we're not doing anything new. So to fix that we go back into the hypershade, select the ramp, under VRamp now just select URamp. You're going to see, this will add a uRamp on the middle of the surface. And now it's going through the faces that we want them to go. Again, we can go into the ramp and tweak this to get the thickness that we're going for. Now let's test this out to see how we're going to make the hair grow only on the white part. So to do that, select the hair, the VRayFur. Go under Pili Mesh VRayFur Properties, scroll down to the end of it, and you're going to find a slot called Density Texture. You're going to drag the ramp to and drop it into the density texture like this. Select this one, scroll down, and drag it on top of the density texture. Immediately we can see the changes happening into the [INAUDIBLE]. So you can see, we don't have any hair here, not at all. The only area where the hair is growing is on the white line. Now, if you go to the Panels, Render Camera, we see the hair is only on the edges. Now we can go ahead and tweak the ramp to get the look that we're going for. So if you want the hair to grow a bit, we can see it more from the camera, just move the black color. Again, the same. Now select the pili mesh, go into the textures, and select the pili shader. Right click Assign Material To Selection. And now, if we open up the render and do a test render, just make sure we're rendering the correct camera. If we zoom in, we can see that the hair is now growing only on the edges of the sphere. So now we can go ahead and tweak the hair so we can get a lot more fur per face. So just go ahead and select the hair, and now, under the VRayFur Properties, where we have Per Face, just go ahead and add 20 per face. And now, if we go ahead and do another render-- now you can see we do have a lot of hair, and this is growing only on the edges, just because we added that mask to the density shader. And feel free to make these as long or as short as you want them. Now, in the next lesson we'll adding some lights to the scene and do a couple final touches to the nucleus and the cell membrane shaders.