Physic Materials are materials that instead
of effecting the appearance of a game object
they effect the way that the object reacts
to the physics engine. Consider the difference
between how a basketball and a bowling ball
might bounce. Whilst there is a difference
in their mass, their surfaces are also
very different and they react to other
surfaces very differently. Physic materials
can be created from the Create button
on the project panel.
And they're edited in the inspector to
control how the surface reacts to another
surface. They do this by controlling friction.
Dynamic Friction is how much friction
exists whilst the object is moving
and Static Friction is how much
force is required in order to move the
object from a static position.
Bounciness does exactly what it sounds like.
It controls how bouncy the object is.
And the Friction Combine settings control
how they respond to another object
with a certain material. Friction Direction
will allow you to control friction
in a particular axis and the dynamic
and static friction 2 properties
will give you control over those three axes.
In this example we've applied this
particular physic material to our power cube
and our work bench.
The physic material is applied to the
collider in any given game object
and you can see that there's a slot for
material within the collider settings.
You can see that if I press play,
it bounces slightly and is also very slippery.
This is because I've used 0 for dynamic
and static friction, meaning there's nothing
stopping it from slipping around and
I've also made it slightly bouncy.
If I make it very bouncy
then it's going to bounce off of the table.
And for example if I wanted to restrict
it's movement in a particular axis
so I can see that the X axis is the direction
in which it's sliding, so what I could do
is go back to that material and I'll set
my friction direction of X to 1 and
increase the dynamic friction. I'm going to turn
bounciness back down to a lower number
so that it doesn't bounce off the table.
And you can see that it's slowing to a halt
because of the amount of friction involved there.
So we could make that slightly lower
and you can see it begins to slide.
So hopefully you can see that with
physic materials you can completely control
the surface of an object
and how it responds to others.