AC3D :: View topic

-WOODY- · Joined: 16 Sep 2003 Posts: 65

Well I had to delete all my other stuff to make room for this, so here it goes.

Tutorial: How to make a tire with real modeled tread

Materials needed: AC3D ( of course ), tire_blueprint.zip, and tire_texture.zip ( optional )
You can download the files here:
tire_blueprint http://home.earthlink.net/~slwoodgraphics/tire_blueprint.zip (NOTE: Redirected - original link dead)
tire_texture http://home.earthlink.net/~slwoodgraphics/tire_texture.zip (NOTE: Redirected - original link dead)
If for some reason you no longer have access to download the files or you see nothing but X's where the photos should be, it's because I have limited bandwidth. You'll have to wait till next month to gain access to it again. Sorry

To begin:
Begin a new scene within AC3D and load your front and side Orth views with the "tire_blueprint.jpg" image. For your pan view, load the "tread_pattern.jpg" image.

( Pic 1 )
With your line tool and in side view, create an arch that follows the front view cut-a-way profile up to the blue line. Make sure that you only have one vertice on each side of the blue line then follow the guide down to the other side. To make sure that the line that follows the blue line is level, you can use the "grid snap" feature or just select the 2 vertices at each end and scale to "0" on the "Y" axis.

( Pic 2 )
After that is created, select the object then in the control panel, hit "move to" and make sure that the coordinance is set to 0, 0, 0. With the object still selected, go into vertex selection mode and control+click ( to only move along one axis ) and drag the selection back up until the top is level with the first blue line on your image guide. This is to insure that the object's center matches that of the tire's center.

( Pic 3 )
Now go into front view and with the oject selected, go into your object menu, then "Revolve" and enter the following settings:
degrees: 360
axis: Z
segments: 40
offset: 0.0
Now hit Revolve.
Making 40 segments will ensure that our object will be smooth without having to subdivide afterwards which will let us keep our sharp tread edges.

( Pic 4 )
While still in front view, select all vertices except for 2 colums at the top and delete which will leave us with a wedge shape. Don't forget to go to "object" and "optimize vertices" and "optimize surfaces" afterward.

( Pic 5 )
When that's done, select the object and rotate along the "Z" axis at 4.5 degrees which will make the top of our wedge level and flat. After that's done, click on "hide" to get it out of our way so we can work on the tread pattern.

( Pic 6 )
Now go into pan view and create a mesh that is 1 colum wide by 12 rows deep and scale to fit the image's width and half the image's depth. Go into vertex selection mode and and select each vertex on either side of a single line then contol+click and drag the line into position. Make sure that there is a line that is on top of each of the yellow dotted lines and that there is a line that intersects at each point where a tread pattern begins and ends at the boarder's edge. The image isn't perfect so just use your best judgement. Make sure that the very bottom line is at the half way point of the tread image.

( Pic 7 )
In surface selection mode, select the first top 2 rows of surfaces and divide once. Combine the doubled rows of surfaces in each colum and delete the leftover vertices until a single division line exists.

( Pic 8 )
Select the vertical vertices of the single line and control+click and drag the line over to the left side of the pattern to line up with the black edge in the upper lefthand corner of the pattern. Snap the bottom 3rd vertice to the vertice to the left on the border of the image. When sapping the line vertices to the border vertices, make sure you do the following...

( Pic 9 )First select the border vertice and in vertex selection mode, hit the ">" button to enter in the location coordinance in the control panel. Select the other vertice that is to be moved then hit the "move to" button to put it in the exact same position as the other vertice. After that, drag a selection box over both vertices then hit "control+T" to snap them both together. Don't forget to select the object then in the menu options select "optomize vertices" afterward. Do this every time you snap vertices together and optimize afterward so you don't run into any problems.

( Pic 10 )
Now in surface selection mode, select the top 5 rows of surfaces to the right of the line we just moved and divide once. Combine the doubled rows of surfaces and delete the leftover vertices.

( Pic 11 )
Move the resulting single line by control+click and dragging the vertices to the left to line up with the second longer edge of the black tread pattern.

( Pic 12 )
After that's done, select the upper 5 rows of surfaces to the right of that line and divide once ( are you seeing the pattern? ). Combine faces and delete leftover vertices to get the single line of division.

( Pic 13 )
Move the resulting single line over to the left and adjust to fit the next black edge of the tread pattern.

( Pic 14 )
You guessed it, do the same thing again to the right of the line by selecting the top 5 rows of surfaces then combining and then deleting leftover vertices.

( Pic 15 )
Move the line to the next edge of the black pattern.

( Pic 16 )
Now select the 3rd, 4th, and 5th rows of surfaces from the top and to the right of the single line and divide once.

( Pic 17 )
After combing surfaces and deleting vertices, adjust the resulting line to match up with the edge of the black tread pattern and snap the top vertice of the line to the outside boarder vertice using the location and move technique. Be sure to optimise afterward.

( Pic 18 )
After completing the upper portion of the tread pattern, add one vertice to each of the 4 lines indicated and in vertex selection mode, select all at once and control+click and drag all of them over slightly to the right to create a slight bend.

( Pic 19 )
In surface mode, select the 10th and 11th rows from the top and divide once. Combine and delete as before.

( Pic 20 )
Move the resulting line over to the left to match the black edge of the small pattern next to the boarder. Snap the top vertice of the line to the one on the boarder and optimize.

( Pic 21 )
In surface mode, select the 9th, 10th, and 11th rows of surfaces from the top and divide once. Do the same as before

( Pic 22 )
Move the line over and adjust and then snap the top vertice of the line to the vertice on the boarder and optimize.

( Pic 23 )
Now select the 7th, 8th, 9th, 10th, and 11th rows of surfaces from the top and divide once.

( Pic 24 )
Do the same with combining and deleting and adjust the single line to the black edge of the pattern.

( Pic 25 )
Select the same number of rows to the right of the single line and divide once.

( Pic 26 )
Repeat as before.

( Pic 27 )
This time select the 9th, 8th, and 7th rows of surfaces and divide.

( Pic 28 )
Adjust line over to the right and snap the bottom vertice to the one on the boarder.

( Pic 29 )
Now select the 7th and 8th row of surfaces to the right of the line and divide once. Do the same as before.

( Pic 30 )
Now adjust as neccessary and snap the bottom vertices together.

( Pic 31 )
Well we're almost done with the tread part. In object selection mode, select the top tread object and dupicate. Now rotate it 180 degrees on the "Y" axis and control+click and drag the object downward to align it to the bottom part of the tread. Now merge the 2 objects together, snap vertices, and optimize. After that, combine the 2 adjoining surfaces together and delete the extra vertices as shown.

( Pic 32 )
Now unhide your sidewall and delete the top surface.

( Pic 33 )
In pan view, select your tread and scale to size. Zoom in as close as you can and size the tread to match up to the 4 corners of the sidewall. Since we wont be subdividing the tire, there is no need to add additional vertices to the sidewall edge to match up with the tread when we go to merge and snap vertices together. If you still want to subdivide your tire when you're done, then at this point, add 3 additional vertices to the sidewall edge and align them horizontally to match up with the 5 vertices in the top and bottom of your tread. If you don't do this and then subdivide, you'll end up with several open gaps in your tire.
If not, then just position the tread level and even with your sidewall and merge. Snap vertices together and optimize.

( Pic 34 )
Now go into side view and contol+click and drag each vertice up until they are even with the green line as shown.

( Pic 35 )
Now in surface mode, select all of the black area of the tread and extrude upward to the red line. Flatten the edge of each side by using the "move to" function with each vertice and optimize vertices and surfaces afterward. Select the vertice edges of each part of the tread and move it back toward itself to create a slight taper. The 3 lines that you created following the yellow dotted line on each side of the tread are now what make up your bend in the tread. Adjust these lines to create the neccessary bend and align the rest of the vertices so you don't see any curling of the surfaces above or below your line.

( Pic 36 )
Now select the surfaces that are directly aligned to the outside edge of your tread and sidewall ( shown in blue ) and delete. Do this as well to the other side.

( Pic 37 )
In front view, rotate your object -4.5 degrees on the Z axis till the right side of your object's vertices of the sidewall are vertical. Now select the upper vertices in your tread that are not directly aligned above the lower vertices and scale to "0" on the "X" axis to straighten them. Now control+click and drag all of them at once till they are directly aligned above the ones below them. Don't mess at all with the vertices in your sidewall because if your're off even slightly, it will make a big difference by the time you multiply these sections a few times. Now rotate the object the other direction in increments of 4.5 degrees till the other side is vertical and repeat this process.

( Pic 38 )
Once that's finished, rotate the object the other direction till the right side is vertical then duplicate. Rotate the duplicated section the opposite direction till the mated halfs are vertical. Now zoom in as close as you possibly can and align the objects together till the vertices are right on top of each other. Now select both halfs and merge objects together. With the merged object still selected, go to vertex selection mode. In your vertex menu, select "snap together by distance" ( trust me, this will save you mountains of time ). In the box that pops up, input this number "0.005" and then hit snap.
Once you do that, be sure to optimize your vertices afterward.

( Pic 39 )
Repeat this process of duplicating, rotating then merging objects till you end up with what you see here. Now you'll have to select 8 sections in surface mode and duplicate.
Rotate the last object in 4.5 degree increments to fit then position and merge.

Now all you have to do is create a rim, maybe a nice tire texture, and 32 pounds of air pressure and you're done.

Woody's AC3D Tire With Tread Tutorial