# Screw Wheels: A Car that goes sideways

http://www.vimeo.com/1643553

Seen in the video above is the fruits of my labour which didn’t take too terribly long. Could have been even more OCD perfect, but the fact that it works is maybe just cool enough. If you were making a real game out of this, it would need some cluges to make gameplay go faster - this is more of a tech demo than anything.

So what is it? It’s all in the tires. Each tire to the car has eight roller-arrays made up of three narrow rollers. If you added up all the wheel-ish constraints up, this car has a hundred wheels. The physics are cool though.

If you’ve ever played Katamari Damacy, controlling the car should be really easy. Just use
WASD for the left side, and UDLR right the right side. Diagonals on either don’t work so well. Use some common sense. update: Diagonal combinations work just fine!

up+up = forward
up+nothing = forward right turn
nothing+up = forward left turn
down+down = backwards
up+down = spin right (0 degree turning radius)
down+up = spin left
right+right = slide right
left+left = slide left

Since there’s an unnecessary amount of inertia you can theoretically mix these controls up. It’s pretty slugish. I’m not sure how to go about improving the speed because making the smallest objects much smaller causes Bullet to get angry. In any case, enjoy

http://www.osysi.net/projects/blender/screw_wheels.blend

Controls are pretty strange, but it’s as you say “like katamary and use common sence” XD
Good going.

Really cool!

Hey this is great.

I got the car to go a lot faster by setting the DYN friction material setting for the floor and the little wheels much higher (that’s why they make tires out of rubber). It’s a lot of fun faster, I could actually catch some air off of the halfpipe.

I didn’t get any results from changing the DYN parameters, but I did get results from tidying up all the masses. The rollers are now 0.05kg, the body is 5kg, and the main wheels now only get roughly 100 in however you measure torque. It runs about the same really… Wheels with wheels is just silly. As soon as the big force tries to apply a reaction forward force, a little wheel transforms a lot of that force in to a rotation. There’s not a whole lot we can do without crippling the rig all together.