Here are a few tips and tricks to creating good ground vehicles in sp3. These include how to increase traction, speed, handling and quite a bit more.
Center of gravity(COG)
The first thing I'll teach you is how to stop tall vehicles, like buses, from tipping over when turning. This can be solved by moving the vehicle's center of gravity, or COG for short. From the orginal version to SP3 X the COG has always been the center of the blue bounding box that appears when you click on a group. The COG can be modified by making a group on the bottom of the vehicle and moving it down so that the distance from the bottom of the vehicle to the box is the SAME as the distance from the bottom of the vehicle to the roof. Then set the box at the very bottom to ignore or noCollision, and you're done, with an untippable vehicle that doesn't need any gyros.
Increasing traction
A lot of vehicles have serious problems when the speed is cranked up. One of the main known solutions is to make thrusters to produce artificial downforce. use the bodywork of the car as a thruster linked to the acceleration key, this will produce downforce when the speed is cranked up.
note; this method may cause unwanted effects, as it will pull your vehicle around in the air a small amount, if your vehicle isn't facing exactly downwards. If you are having problems, attaching extra non-collision objects to the wheels and/ or body instead can also work.
- An alternate method is to eliminate the need for traction. Connect the wheels to your vehicle with hinges so they spin freely. Then go to the wheels that turn and add another servo EXACTLY centred in between any existing servos. Set this new servo to rotate with the wheels. You can then connect a thruster to this servo. Play around with the thruster settings and controllers a bit and you can get a car running at the required speed with no need for any traction. This method can also be used to create amphibious vehicles that will move on the water plane such as this one.
Optimising your vehicles for better performance
A large problem suffered with using traction thrusters to push the car down is that when too much traction is applied the steering wheels start to crumble. This can be solved in two known methods:
- decreasing the traction: if the wheels are crumbling and your vehicle is not particularly fast then you should consider lowering the strength of the traction thrusters.
- increasing the strength of the steering wheels: this is only reccomended in high speed vehicles, because lwering the amount of traction is the best way in most cases. To do this you need to move the block holding the wheel to the car closer to it's steering servo, this will increase the strength by a lot and shoulld stop the wheels from crumpling.
For optimising models by reducing lag, go here: optimising sp models