Game Physics Engine Development, 2nd Edition

13.3 Simple Collision Algorithms 309

data->friction, data->restitution);

data->addContacts(1);

return 1;

}

Strictly, this isn’t a sphere–plane collison but a sphere–half-space collision.

Figure 13.10 shows the difference. The half-space is treated as if the whole region on

the back of the plane is solid. So, an object interpenetrating will always have its contact

normal pointing in the direction of the plane normal. Even if the object is completely

behind the plane, the contact will be generated. True planes are infinitely thin. An

object on the back side of the plane will have its contact normal in the opposite direc-

tion to the plane normal. True