# 3D Cartesian coördinates

How do you draw an Cartesian 3D-axis-system?
The Y-axis seems to have some perspective; what's the position of the observer?
What's the 'way' of placement, and why?

Dank u.

tiny-tim
Homework Helper
Welcome to PF!

Hi Valianth! Welcome to PF!

The convention is that you draw the z-axis up, and the y-axis anti-clockwise from the x-axis … but at an angle, so that it "looks" 3D!

This is so that it agrees with the usual way of looking at 2D graph paper. And so that the cross-product (i x j = k) looks right!

And you draw it from the perspective of someone in the x and z positive and y negative sector.