Front wheels - single axis rotation - for games

Rigging
1

Ok, I’m rigging a truck, and I want to make the rig very animator friendly. Here is a picture of my current front end setup.

So, the bar on the left steers the wheels, then the circles are meant for spinning the wheels, as well as up/down motion.

The problem I have run into is that when I turn the wheels, if I spin the them as well, they go all wobbly. I want to have a single attribute for the spin, but in order to make them spin properly, they need to spin on all three axis. The solution I found was to group the wheel joint. Then I turn the wheels by rotating the group, and spin them with the joint. This way the spin in on a single axis.

Works perfect, until I go to export and it tells me that there is more than 1 root joint, so I cant export it.

What’s the best solution for this? Ive been beating my head on this for a few hours now, which seems extreme for how easy this should be.

Ive tried 2 joints on top of each other, 1 for steering and 1 for rotating, but then skinning it 50 50 ruined that because it folds in itself.

Thanks

Stefan

edit: I should probably mention, this is for cycles, so the auto spin when translating the car wont work. I need to be able to spin them seperately

2

Instead of Grouping the joint, cant you just put the spin control under a group that is controlled by the turning control either via Set driven key or nodes? (grouping a joint doesnt feel like a kind solution for poor game exporters :): )

3

Bah, I figured it out. I feel really dumb now.

Thanks for the reply tistatos. It wasnt really the controller itself that was messing up. it was that when I spun the controller, the way it was connected to the joint, the joint would spin in more than the x axis.

I was trying to connect the controllers using constraints and driven keys. But the way I solved it is that I point constraint the spin controls to the joint for the up/down motion. Then I used set driven keys to make them steer with the other controller. And to get the rotation to spin properly, I used the connection editor, so that the x axis of the joint is directly connected to the x axis of the controller. I have no idea why it wouldn’t work with actual constraints, but it works perfectly now, and exports. So I’m happy.