View Full Version : Car Controls

TJ Graphics
06-24-2019, 06:39 AM
I've been working on building a vehicle rig using the "Remote_Controlled_Car_Plane.lws" as a reference and tutorial. It looks like a good starting point but there are some issues that I can't resolve. Mainly that the front wheels act in an unwanted manner. When the car makes tight turns the front wheels lean. If you rotate the view around and look at the wheel "head-on" you'll see the wheel is not perpendicular to the ground plane. I'm trying to lock down the wheel so it only spins on its axle and turns for steering purposes. The rear wheels don't do this so I'm thinking it's in the DoF constraint.

What I'm looking for some hardcore, in-depth documentation on bullet dynamics. I've watched all the videos on the internet (mostly on youtube) and read all the websites that I can find. Usually through google searches. Does anybody know of any additional information sources?


06-24-2019, 08:38 AM
Have you tried these rigs?

(Have not tried myself, please post renders if they work out for you)

/Edit, original thread with former commercial plugin, now freeware: https://forums.newtek.com/showthread.php?84102-Vehicle-Rigger-1-0-for-Lightwave-released!

TJ Graphics
06-25-2019, 06:21 AM
I was hoping to stick with the bullet dynamic system in Lightwave 2019 (since I spend the money on it). With a couple of minor problems it works great and is easy to use. I think the problems can be overcome if I understood more about its function.

Thanks for the sites though.

06-25-2019, 10:09 AM
Well, here are more tips, including an example rig using bullet physics: https://forums.newtek.com/showthread.php?157820-Stick-car-to-varied-ground&highlight=Vehicle

06-25-2019, 10:39 AM
FYI, when a real-world car is turning, the front wheels bend out of the vertical by intention:


I don't know if the Bullet car rig you're working with does this intentionally or not. Unless the Bullet Hinge for the wheel bearing actually breaks (i.e. the blue half of the hinge separates from the aqua half of the hinge), then it may be by design.

Yes, I regularly use a Degrees-of-Freedom constraint in addition to a Hinge constraint between the same two Bodies. One of the bugs (IMO) of LW's implementation of Bullet Hinge constraint is that even if the "Breakable" flag is clear, or the flag is set with a HUGE Breaking Force specified, the halves of the hinge are still able to separate.

IMO, when the "Breakfable" flag is not set, there shouldn't be ANY possibility that the halves of the Hinge will separate either linearly or rotationally (are those actually words? :) ).


TJ Graphics
06-25-2019, 08:23 PM
True the wheels move a bit but there is too much movement in the rig file. The also move forward and back with respect to the car body. It's like the wheels are just suspended from the body by a spring. Granted in the rig it technically is but in a real car the wheels are attached "rigidly" to the car but are allowed to move in only 2 ways. Up and down for suspension and rotating for steering. I'd like to restrict the motion to those 2 manners.

I'm thinking about separating the 2 motions, instead of having constraints that use a spring moving up and down PLUS the DoF to provide steering. If I isolate the up and down spring and the steering DoF to separate parts I'm thinking this will prevent the DoF from allowing the wheel to swing around in an unwanted manner. I still need to work out the bugs though.

I do appreciate any thoughts of ideas anybody has though.