Join Ryan Kittleson for an in-depth discussion in this video Making a tire with radial symmetry, part of Modeling a Female Android in ZBrush.
We're going to start making the wheels in a fresh ZBrush scene. So and let's go ahead and get rid of the light box by hitting comma, and let's go to cylinder. And click that once more so we can get one of the primitives. I want to get the ring 3D. So let's go ahead and click and drag that into the canvas. And let's go into Edit mode. Now, since this is a primitive, we have access to its initial properties. So what we can do is change its radius, for example. So I want this to be like a thinner racing tire. So something like that looks good.
And let's also zoom in on it. Because I want to take a look at its subdivisions. So right now we can see that all the polygons that make this up are really long and stretched out. So I want to adjust the L divide and the S divide. Let's try a wire-frame to make this easier to see. Shift+F. So, let's crank up L-Divide all the way, and then S-Divide, let's crank that down a little bit so that the polygons are more square. That looks pretty good. Okay, so next thing that we need to do is make this an actual, sculptable object. So make a polymesh 3D will convert it from a primitive to a sculptable mesh.
Alright, hit Shift+F to turn off wire frame. Next thing I want to do is give this some more detail, because we need to sculpt the tread pattern in here. We just don't have enough polygons to do that. So I'm going to hit Ctrl+D a few times, to see the active points increasing up here each time, and we want to get this somewhere around 2.8 million. Somewhere in the low millions. So let's zoom in on this and I just want to show you as an example. If you were crazy, you'd want to come in here and try to sculp all this tread pattern by hand.
But that would just take forever and there was no way you could get it very precise. So let's not do that. I'm going to hit Ctrl+Z to undo. So instead what we're going to do is use radial symmetry. So let's go into Transform and turn on Symmetry. So right now, it's the standard symmetry but what we want to do is have it be radial and we also want a lot of different radial points. So right now its at eight, so let me zoom out a little bit. So, you can see it's creating this radial pattern of symmetrical points.
So, we want to actually have it going in a different direction and more of them. So let's go to Transform. Let's crank up the radial count, and then let's also set this to z. And let's turn off x. So, ZBrush did something really weird right there. The radial count, the numbers stayed the same, but the, the little slider drop-down. You actually want to crank that back up to 100 now. That's really weird, I'm not sure why ZBrush is doing that, but we want 100 radial count. And we want it to be in the z axis. So now you can see, we're getting all these dots, all the way around the wheel.
That's great. So let's zoom in on this now. Okay, so now you really just draw whatever kind of tread pattern you want. I'm just going to draw something out here, that looks sufficiently futuristic. Feel free to make whatever you want there, alright, that looks pretty good. Okay, so there's one last thing I want to do. This ring is now at 2.8 million points which is actually half the number of polygons in the object. So there's actually over 5 million polygons in this object. It might weigh down the scene so, what we can do is simplify this.
I'm going to go into z plugin and let's go to Decimation Master. And click Preprocess Current. So what this is going to do is analyze the object for any unnecessary polygons. And then it's gong to prioritize those. And allow us to strip out any polygons that aren't contributing to the shape. And now this can take a couple of minutes to do because it's analyzing millions of polygons. Okay, so after a few minutes it's done. And now that it's prepossessed that, we can go into z plug in again. And set a Decimation amount.
I usually find about 10% works pretty well for most circumstances. We can always undo and change it if it's not quite right. Alright, so click Decimate Current. And what this is going to do now is strip out all those unnecessary polygons. So, let's zoom in here, and see what we've got. So, I'm going to hit Shift+F. So you can see, now the model is a lot less dense, and it cut out polygons more in places where there wasn't much happening, and it left more polygons in, in places that had detail, and it brought the total polygon count down to less than one million.
However, from a distance, you would never tell that there was any less amount of polygons. Radial symmetry is one of those features that I don't really use a whole lot but in the right situations, like with this tire, it's a really great way to work.
- Gathering reference materials
- Getting a base model
- Stylizing the android's body
- Exploring design concepts
- Making pivoting joints
- Creating precise mechanical shapes
- Adding thickness to panels with Panel Loops
- Making a foot with DynaMesh
- Making a tire with radial symmetry
- Reducing polygons with Decimation Master
- Preparing for rigging and posing
- Applying materials