Intersection Test Question.

Since the wheels are cylindrical, and the cylinder is ... "parallel" to the terrain below...

Check the distance from the center of the cylinder to the terrain. That is, from the line that is the center, to the plane that is the terrain. :-)

Scout

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All polynomials are funny - some to a higher degree.
Furthermore, polynomials of degree zero are constantly funny.

That works assuming I know that the wheel is contacting only one triangle, however, I want to be able to test for multiple contact points on the terrain. Also, there is the case of when the vehicle is in the air because of a jump, I need a way of figuring out when the wheels collide with the terrain.

Anyone else got any ideas on the subject?


Cbmeredith.

In your case, I'd go for ellipsoids, if the car wheel do not need to contact with things other than triangles. Ellipsoid intersctions are like sphere intersections, except you scale the triangle with the ellipsoid radius (stretch/compress the triangle on the X, Y and Z axis), do a sphere of unit radius collision detection with the modified triangle, and de-stretch the collision information back to the world.

The ellipsoid for your tyre will be quite close to a cylinder, and will model it nicely and efficiently. But doing col det of ellipsoids with things other than triangles and spheres is complicated.

[edited by - oliii on January 8, 2004 4:27:30 AM]