Car Tutorial Guide (Unity3d): Exploring an Alternative Physical Model (part 2 of 3)

Before we begin, I want to warn you that this is not a translation of the official manual, but my personal study of alternative physics in a car from the manual of the Car Tutorial.

Part 1
Part 2
Part 3

Exploring an alternative physical model:

Part 1
Part 3
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PS This article presents the main examples, in the video there are one and a half times more of them, so that anyone is interested in each of these examples, watch the video:



In this section, we study the mass of the car and the influence of the location of the center of gravity in our car.

So, as we know from the previous article, the mass of our car = 1445kg.



Center of gravity (CoG) - placed as follows:




With these characteristics, our car can be safely controlled. During the test, all the settings will be what we set in the previous article. In terms of speed with the characteristics above. we dial 102 km / h in about 6 seconds. ie, our car accelerates very quickly with the settings that we set earlier and with the center of gravity as shown in the picture above.



Increase the mass of our facility to 5000 kg:



Let's see what happens. We for 10 seconds on the same route accelerated only to 89 km / h. After stupidly drove to the slope and the speed naturally fell. That is, with the increase in mass, our "acceleration" of our car fell. Because our car has become heavier.



Increase the mass of our facility to 10,000 kg.



Let's see what happens. For 20 seconds on the same route we only accelerated to 69 km / h. After stupidly drove to the slope and the speed naturally fell. Ie with the increase in mass, our “acceleration” of our car again fell. Because our car has become heavier.



I could not help noticing the "tight" control - the car ate turned. And on the slope did not drive, rolled back down the slope, there was not enough engine power to accelerate up the hill.



From here we now know that in order to create a truck, an important factor will be the change in body weight, to a real one (like a real car).

With the mass of the car figured out a bit now I will present a dozen options for the location of CoG (Center of Mass) on the car. I will evaluate each CoG location on this car by three parameters. Speed, Stability, Handling . On a scale of 1-5. Change the weight of the car by default "1445 kg."

Option 1

Speed ​​- 5;
Resistance - 4;
Manageability -3;

In principle, a good mb option is slightly higher just below, to position the center of mass of the car and to lose the disadvantage of the car.
Speed ​​- excellent acceleration, high speed.
Resilience - when flying something with its nose, it bends a little bit, almost turned over from a high mountain, but quickly recovered.
Handling - lost control at high speed when turning on the slopes (skidded).

Option 2

Speed ​​- 5;
Resistance - 3;
Manageability -4;

In principle, a good option.
Speed ​​- excellent acceleration, high speed.
Stability - when flying as it is not clear, then it flies from a small hill with the front elevated, then it is dipped from the high mountain with its nose and turned on its side, with some repulsive defects.
Handling - control is quite good, only at high speed tugovat.

3 Option

Speed ​​- 4;
Resistance - 3;
Manageability -3;

The option is average.
Speed ​​- good acceleration, excellent speed, but acceleration on the slopes is slower than on a flat road.
Stability - when flying flies with a raised top.
Handling - control is quite high speed and a little tight turn and skids are created a little.

4 Option

Speed ​​- 4;
Resistance - 3;
Manageability -3;

The option is average.
Speed ​​- good acceleration, excellent speed. But on the slopes acceleration is slower than on a flat road.
Stability - when flying flies with a raised top.
Handling - control is quite high speed and a little tight turn and skids are created a little.

5 Option

Speed ​​- 5;
Resistance - 5;
Handling - 2;

The option is not very.
Speed ​​- good acceleration, excellent speed.
Sustainability - sustainability is even better than necessary (you need to try to turn the machine over).
Handling - lost control at high speed when turning on the slopes (very strong on light corners).

6 Option

Speed ​​- 5;
Resistance - 5;
Manageability - 4;

The option is almost excellent, a small contusion with drifts.
Speed ​​- good acceleration, excellent speed.
Stability - stability is excellent.
Handling is a small problem with skidding when cornering, but in principle for a racing simulator, that's the thing.

7 Option

Speed ​​-5;
Resistance - 2;
Manageability - 4;

The option is not very.
Speed ​​- good acceleration, excellent speed.
Resilience - Resilience machine can easily roll over.
Handling - minor problems with skidding on bends.

8 Option

Speed ​​- 5;
Resistance - 2;
Manageability - 4;

The option is almost excellent, a small contusion with drifts.
Speed ​​- good acceleration, excellent speed.
Stability - the machine can easily roll over.
Handling - minor problems with skidding on bends.

9 option

Speed ​​- 4;
Resistance - 5;
Manageability - 4;

The option is very good.
Speed ​​- average acceleration, good speed.
Resilience is great.
Handling - Tight turns.

Conclusions: Of course, not only body weight and center of gravity affect our characteristics. But setting the center of gravity correctly will solve some of your problems in the future. I believe that option 6 and 9 are the most acceptable, with option 6 for a car and possibly option 9 for a truck. Why is it possible? Because it must be individually selected and tested. And with already pre-configured scripts.