From the course: ZBrush: Tips & Tricks

Making cartoony eyes for 3D printing - ZBrush Tutorial

From the course: ZBrush: Tips & Tricks

Making cartoony eyes for 3D printing

- Traditional sculptors have been using ingenious tricks for thousands of years to carve believable eyes out of stone, without the use of colors or transparent, glossy materials. When sculpting a character for 3D printing, we can use some of those same techniques, along with ZBrush's new Boolean features for complete control over the look of the eyes. In this video, I'll show you how to use ZBrush's modern tools to duplicate some age-old tricks. Okay, so let's say we're going to be needing to 3D-print this elf with some eyes that will work sculpturally, but don't necessarily have the color, or the transparency, or the reflective properties of real eyes. Let's start out by just dropping in a new sphere. I'm going to come down to Append in my SubTool palette, and let's just append a regular old sphere. I'm going to select that, and let's come around to the side view. I'm going to hold down Shift so it snaps to a perfect side view. Let's move this into the center, and now I'm going to go into my Gizmo by hitting W, and let's just go ahead and rotate this forward a little bit just so the pull of the sphere is facing forward. Then I'm going to hold down Shift so it snaps to 90 degrees. You can see, if I hit Shift + F to turn on wireframe, you can see that pull is facing forward. It's not super important, but it's just something I like to do. Now let's get this eye ball sized appropriately. I'm going to turn on Transparent mode, make it easier to see that when it's inside the head. Let's see, I'll just move this forward somewhat, and since it's cartoony, we can play with the squash and stretch of it. I just want to move this and position it, and looks like we can scale it this way as well, somewhat. Going to hit Shift-F to turn off wireframe and just try to get this positioned, here. Playing a little bit with the proportions. Okay, now we can turn off Transparent mode, because the eye's now on the outside. Just want to adjust the position a little bit, here. Let's see how this looks. Maybe I'll squash this a little bit more in that direction. Okay, we can always finesse that later, but that's pretty good for now. This eye is going to be made up of several different SubTools that we're going to combine with Booleans, so let me rename this, so that I keep all of my SubTools straight in my mind. Let's just change this one to eye ball. Now let's make a pupil. For this, I'm going to cut the shape of the pupil out of the eye ball. We can just use the same eye ball shape we already have, so I'm going to duplicate that, and we'll rename this to eye pupil. We can set this to Subtractive mode, so it cuts out. I'm going to change the mode here to Subtractive, and we also need to make the eye ball a Start Group. Let's move that pupil forward just a little bit, and let's shrink it down somewhat as well. Okay, now, let's see what this looks like with a Boolean preview turned on. Come up here to Live Boolean and turn that on, and you can see, now, it actually shows us what it looks like with the pupil cut out from the eye ball. I'm just going to adjust some of these proportions a little bit. Maybe make that a little bit smaller, or not that small. I'll see what happens, we can try to move this around in different positions, I'll try to get that centered a little bit better. Okay, the next thing I want to do is create a little highlight shape. Basically, I want to make a shape that simulates the effect of sunlight reflecting off of the eye ball, but obviously, we can't do shiny material with 3D printing, so let's simulate this with a shape that's going to catch the light. Let's append a new SubTool. We'll go to Append, get the cylinder. Let's go ahead and select this, make it active. Now, I'm going to come around to a side view and hold down Shift, so it snaps to a perfect side view. Let's just rotate this down, holding down Shift so it snaps to a perfect 90-degree angle. Let's see, I'll adjust the size on this. Let's turn on Transparent mode so I can see this through the head. Let's move this into place, and let's see what this looks like from the front view. Okay, I need to shift it over to the side a little bit. Let's push that back inside. We can turn off Transparent mode. This is where it starts to get a little bit tricky. With Booleans, there's this order of operations of what gets cut out from what, and what gets added to what, and so on, and so forth. I'm going to go through a couple steps here that might not make a lot of sense, or be very intuitive, but in the end, you'll see that it works, and then hopefully you can replicate these steps to make something similar in the future. Let's rename this SubTool to something like eye highlight, and to make everything work together, what I'm going to do is create an object that envelops the entire eye. This is so that all the Boolean operations work appropriately, and it's probably not going to make a lot of sense as I make it, but in the end, we'll see how it all works. Let's create a new SubTool, append, and I'll just get a cube. That's fine. Basically, I want this cube to be overlapping the eyes. It's okay if it's much bigger than the eyes, just as long as it's completely covering up the eyes. I'll rename this one to eye envelope, and let's put this on the top of the eyes. We'll make this a new Start Group. Let's make this one no longer a Start Group, and I'm going to drop this eye ball down to the bottom. I'm going to make it an overlap mode, so now you can see with our Boolean preview, it's actually creating a nice eye. Let me get out of the Gizmo mode so you can see that more clearly. We've got, basically, the eye envelope is one object that's covering the entire eye part of the head, and then we've got an eye pupil as a subtraction mode. What this is doing is it's subtracting this pupil shape from the cube, so it's making this hollow space inside the cube. Then, below that, the next SubTool is the eye highlight. It's adding this cylinder shape. After cutting out the hollow shape for the pupil, it's adding a cylinder, and then the eye ball, it's using the overlap mode. Only the things that are overlapping are visible. There's the eye ball shape, which is overlapping this entire eye envelope, and also the eye highlight that's added in to leave us with, simply, an eye ball shape. The power of this is it allows us to make modifications to the size and placement of any of these components of the eye ball. Let's say we want to reposition the pupil, for example. So, we can go back into our Gizmo and we can reposition where this pupil lies. We bring it in a little bit, maybe, right here. We can change the size of the highlight, for example. We could make that bigger or smaller, whatever looks good. And then we could change the placement of all of it together. What I could do for this is go into Transpose All Selected Subtools mode by clicking on this, and now we can move multiple SubTools together at once. Now, as it is right now, it moves all of them. It moves everything together. But what if I just want to move the eye by itself? I'm going to hit Control + Z to undo that. In order to select just certain SubTools to move, it's kind of like making a selection with the selection brush, so I'm going to hold down Control + Shift and click on the head. Now, when I move this, it only moves the head, and anything with the hatch lines stays where it is. I'll just hit Control + Z to undo that. What I want to do is actually invert this SubTool selection, so I'm going to hold down Control + Shift, and click in an open area. That inverts which SubTools can move. Now you can see, we can move this whole eye assembly together as one. Let's see, I could shrink it if I wanted to, make it larger. I could rotate it. Whatever I need to do. Let's hit Control + Z, though, because I liked it where it was. When you're happy with the placement of everything, what we can do is get out of this multi-SubTool move mode, but first, I want to clear any of the hatch lines. To do this, I'm going to hold down Control + Shift, and click and drag over everything. Now we can get out of Transpose All Selected Subtools mode. Now, let's duplicate this eye over to the other side. I'll go ahead and start with the eye ball SubTool, and what I want to do is duplicate this over to the other side. Let's go to Zplugin > SubTool Master > Mirror. What I want to do is merge into one SubTool and merge across the X-axis. Looks good. Let's do the same thing with the eye pupil. Zplugin, Mirror, same settings, looks good. Let's do the same thing with the eye highlight. Zplugin, Mirror, looks good. One thing I want to change here is that the eye highlight shouldn't be symmetrical. It should highlight on the same side of the sphere, as if the light source is coming from the same direction. For this, I'm going to mask off one of these. Hold down Control, click and drag a mask over one of these. You're not really going to be able to see the mask in Live Boolean mode, but if I turn this off, you won't be able to see it because it's got that box over it. I'll just turn that back on, and we'll just know that it's masked. We'll go into Gizmo mode, and we'll just slide this over. Okay, looks good. Let's just clear that mask by holding down Control + Alt and clicking and dragging over everything. Now let's move this just to make sure it's cleared. Okay, good. I'll hit Control + Z to undo that. Now, you can still make adjustments to the proportions of any of this. So, for example, if we want to make the eye pupil bigger or smaller, what we could do is go to Scale, here, and scale this up. However, we have to make a certain adjustment here, because it's scaling both of them from this one point. If I hit Control + Z to undo that, what we can actually do is hold down Control as we click on this, and it will inflate. That changes the size up and down, 'cause it just inflates it in or out. Okay, we're almost done. Now we need to lock in all of these Boolean operations to create a SubTool that we could actually 3D-print, because right now, these Booleans are just a preview mode. Let's go back into our Draw mode and let's go ahead and convert all of these Booleans into a Boolean mesh. Let's go ahead and click on that. What this does is it creates a new tool here in our tool palette that is made up of the original elf head, and then also the eye balls that have now been combined into one solid mesh. If we hit Shift + F to turn on wireframe, we can zoom in here and we can see how it has combined these different SubTools into one by basically just cutting them and sewing up the seams. Now you could export this for 3D printing, and it's one solid piece of geometry that should print, no problem. There we have it. Some of this, unfortunately, can feel a little bit cumbersome, but as you practice with Booleans more, it will start to feel like a very natural way to work, especially if you need the ability to quickly make design variations.

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