Your online Softimage Educational Resource

The blog has been online for more than 4 years and there’s still not a single post even remotely related to the delicious brew called coffee… Perhaps it will someday, but in the meantime you can read the articles about Softimage. Most of the material are tutorials and Q&As I’ve written for 3D World Magazine sometime between today and 2003. If you have any questions please don’t hesitate sending me an email.

Thanks to Letterbox Animation Studios for hosting all the scene files.

Make sure you visit their for 100s of hours of free XSI video tutorials.

Tuesday, August 5, 2008

Modeling a Tire

Save different versions of your scene before you freeze the object to ensure you’ll easily be able to go back and make changes to the original tread pattern.

The first thing to do is to get hold of good reference material; such can easily be obtained by searching Google or any of the manufacturer’s WebPages. Once settle on what type of tread pattern to create, either load it as a Rotoscope image in XSI or use it as it is.

Start by creating a Grid and lower the Y Length to 1.5. Increase the U Subdivisions to 19 or so and the V to 2. Select the middle V edge row and, in the top viewport, move it downwards so its just above the end of the grid. Move each of the U edge rows to form the proper gaps between the treads (additional screenshots can be found on the cover CD). Next move the polygons so you get sort of a V-shaped pattern. Select all the polygons that are to form the height of the tread, press [CTRL + D] to duplicate them and move them slightly upwards. With the polygons still selected, from the Modify>Poly.Mesh menu choose Bevel Components.

With the first section completed it’s time to create the remaining part of the tire. With your object selected, press [CTRL + Shift + D] to open the Duplicate Multiple PPG. Enter 45 as number of Copies and switch to the Transform tab. In the Z Translation box, enter 1.5 and click OK. Select all objects and from the Create>Poly.Mesh menu choose Merge. Lower the Tolerance to about 0.1 and click the Delete button in the PPG to freeze the new object. In the Transform Panel, click Transform>Move Center to Bounding Box before applying a Modify>Deform>Bend operator. In the PPG, change the Axis to Z and set the Angle to about -382. Change the Radius to about 11 and set the Z Offset to -37. To weld the seam together choose Modify>Poly.Mesh>Boundary Points/Edges. Hold down the [Alt] button and click with the middle mouse button on one of the edges at the very end at each side of the tire (hold down [Shift] as well to add to the selection) to select the entire row/loop. Duplicate the edges and scale them down a couple of times to form the side of the tire.

The project files used in this tutorial can be found at:

By focusing on a single section of the tread pattern you can allow more attention to go in to details; a technique that works for just about any type of tire.

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