Question

When applying transformations to objects we use glPushMatrix/glPopMatrix. But why don’t we use glLoadIdentity only instead?

Thus

    glPushMatrix()
    ..apply tranformations
    ...draw object
    glPopMatrix()
    glPushMatrix()
    ..apply tranformations
    ...draw object
    glPopMatrix()

This is how its supposed to be done right?

can become

    glLoadIdentity()
    ..apply tranformations
    ...draw object
    glLoadIdentity()
    ..apply tranformations
    ...draw object

Answer 1

Because you wouldn’t be able to do this:

glPushMatrix()
..apply tranformations
glPushMatrix()
..apply ADDITIONAL transformations
..draw object with combined transforms
glPopMatrix()
...draw object without the additional transforms.
glPopMatrix()