What is exactly 3d perspective?

[geuz]

Hi.

I'm wondering about the meaning of property "perspective" of 3d objects.

Are the x,y,z coordinates of the object, the rotation angles, the rotation pivot and the vanishing point not enough to calculate everything?

[geuz]

Hi.

I'm wondering about the meaning of property "perspective" of 3d objects.

Are the x,y,z coordinates of the object, the rotation angles, the rotation pivot and the vanishing point not enough to calculate everything?

Edit
I found an explanation
"The perspective angle determines how quickly parallel lines converge to the vanishing point. The greater the angle, the quicker the convergence, and therefore the more severe and distorted the illustration appears."
from

But still a bit unclear. If I draw a room on paper, with one vanishing point, I make horizontal lines and straight lines from the vanishing point to where I need them. Is the length of lines making "depth" not calculated only using the "real" length and the vanishing point? do I need "perspective" value?