There are 2 tutorials for the tires. This and the previous tutorial. The first is basic but this is a more complicated tutorial with a total of 4 different versions.
Congratulations on making it this far; you've proven you have what it takes to finish this book. At this point you don't need me explaining the simple things like the differences between or how to select vertices, edges or faces. Feel free to swivel the camera this way and that. I'll leave it to you to decide when to turn snap on or off "Limit Selection to visible". At every step I hope you think, “Ah-ha, now it looks more like a tire!” since that's essentially what I did. I'm writing this tutorial because I don't want this book to become outdated. Also... I really like tires!
== Build the Tire ==
This is the real world wheel we'll be modelling. It has three parts: 1) tire 2) rim 3) hub. We'll create the wheel laying down starting with the tire and working our way in.
=== The wheel ===
Delete the default cube and hit Num7 to go to the top view.
Center the cursor and add cylinder with 32 vertices, radius 4, and depth 2. Set Cap Fill Type to nothing.
Set snapping to Increment: Shift + Ctrl + Tab and enable snapping: Shift + Tab .
Next we will make a series of cylinders which will become the tire and the rim. Switch to edit mode. Extrude the cylinder inwards by pressing E Esc S Shift + Z 0 . 9 Enter . Do this a total of two times, then extrude another cylinder inwards by 0.8.
Unselect everything ( A ) then select only the vertical edges of the innermost cylinder, as follows: ensure "limit selection to visible" is turned off, switch to vertex-select mode, circle-select the innermost vertices, switch to side view ( NUM1 ) and edge-select mode, block-unselect the top edges with Shift + LMB , and do the same for the bottom edges.
Merge-collapse ( Alt + M >> Collapse) these vertical edges to create a circle that's vertically in the center of the other cylinders.
=== The Hub ===
The inner ring should be already selected. Extrude it and scale to 0.4. Move the new circle down by 0.5, then extrude it up ( E Z ) by 0.5. Extrude and scale to 0.25. Move the circle up by 0.15, and lastly press F to make a face in the inner circle.
To be safe before saving highlight all and remove doubles. We can add different types of tread to this simple tire. If you're feeling ambitious come up with your own tread design. Save your work now.
== Finish your tire several versions ==
Working on the vertical faces of the outermost cylinder in face select mode.
=== Type 1 ===
Subdivide the outer faces one time, and rotate, with Z-Lock, the newly created central edge by 12.
Stager select every other outer face and extrude size out 1.15 ("Ekey" then "Enter" then S and then 1.15). Make sure your sizing outward from the center of the wheel. For quick selecting, Alt-select the two rings of faces and press Select-Checker Deselect
What you can also do is Alt+E click on individual faces, 1.15 and then "S key" scale it down some points.
=== Type 2 ===
This tread is a little trickier but the extra work is worth it.
Subdivide the outer faces and change the number of cuts to 2. There are now 96x3 outer faces. Think of these as being on 3 levels bottom middle and top.
Select 2 of the bottom faces skip 4 faces then select 2 more go all the way around the circle. The pattern for the middle level is select 2 skip one select 2 starting at the top left vertex of the bottom level. The pattern of the top is the same as the bottom select 2 skip 4 start at the top right vertex of the middle level just not the same middle selection that the bottom is... see the picture :)
Extrude size out 1.15 from the center of the wheel "Ekey" then "Enter" then S then 1.15)
=== Type 3 ===
Evenly loop-cut the faces of the outer cylinder
CTRL-R, center the mouse on the outer cylinder -> Enter -> Enter.
Now subdivide the outer cylinder.
There are now 3 inner edges.
rotate, with Z-Lock the top inner edge by 12 and the bottom inner edge by -12.
This time make a Z-pattern with the faces and extrude size out by 1.15 from the center of the wheel "Ekey" then "Enter" then S then 1.15).
== Finishing ==
To get the wheel standing up lock the y axis and rotate everything 90°
The wheel object as well as the wheel mesh are both named Cylinder in the outliner lets rename both Wheel. Right click the name and select rename
Lets add a sub modifier and set shading to smooth.
Crease the hub edges. Shift EKEY 1 enter. By the way the easiest way to remove a crease is just to add a negative crease. Shift EKEY -1.
== Colouring ==
Now for some color.
By the way, think of diffuse as being the base color and specular as being the reflected color. If you're curious about words like lambert and fresnel just look them up in your favorite dictionary.
In the properties menu select the materials icon.
Create three material slots by clicking the plus button that's above the minus button 3 times.
Select each material slot and click new to add a material to it. Name the first material Rim, the second Tire and the last Hub.
We'll leave the rim default white. Select Tire and change the diffuse color to almost black RGB of 0.010 and the specular intensity to 1. This gives our tire a very shiny black look. Give the hub a dull gray look by setting the diffuse color to RGB 0.05.
The first material added becomes the default material for the entire object. So we only need to select the parts of the wheel mesh that are not rim.
Select the tire that's the two outer cylinders- with the tire material highlighted click assign.
To make selecting the hub easier close the subsurf eye in either the properties or outliner menu. Assign the hub material to the hub mesh. I've left adding the red hub oil seal up to you.
That's it! Hopefully my instructions weren't too painful. Be sure to save and good luck!
If you want you can create a more complex tire. Otherwise you can skip this.
== Creating a more complex tire ==
Start by loading a basic cylinder and rotating it so it rests on its side.
Next, remove the faces from the top, and bottom of the cylinder.
Now Press the num5 key to enter orthographic view.
Then press num7 to view the front of the cylinder.
Then click on "Loop cut and Slide" in the tools shelf and make a cut of ".5" to each side as shown in the picture (ctrl+R -> 3 -> Enter -> Enter) select the middle then (X -> edge loops).
Next, make 2 more cuts .4 on each side (ctrl+R -> 4 -> Enter -> Enter) select the unneeded then (X -> edge loops).
Next, press the b key to enter box select mode.
you will want to select all the middle faces.
Next. type "S key" then X or Y, dependent on direction your cylinder is in, then .5
Then press the A key to select everything, then "S key" -> X or Y, and type .5 to squish the whole wheel.
Then use the "B key" to reselect the middle faces.
Now, with the Middle faces still selected rotate them so they look similar to the picture shown by typing "R key" "X key" or "Y key" and then"10".
Next, select all the faces beside the middle and in the middle and rotate them all in the opposite direction so it looks similar to the picture shown by typing "R key" "X key" or "Y key" and then"-10".
Next press the A key to unselect everything.
Then start selecting faces as shown in the picture. Continue this all the way around the wheel leaving 1 space of unselected faces in-between each row.
With the faces selected press "Shift+S" then "Cursor to Center" then EKEY then ESC and then "S key" to scale them. While scaling type ".9" then press enter.
Next, select all of the side edges as shown and Then Press the "S key" and type .7 then press enter.
Type "S key" then X or Y, and then type "1.5" to move both sides outward slightly.
Type "E key" then "Enter" , then the "S key" type "0.75" as shown in the image.
Feel free to add the hub cap from the previous wheel, or one of your own design.