Parametric Equation from Two Points

With line $l$ through points $P=(x_1,y_1,z_1)$, $Q=(x_2,y_2,z_2)$

• $x=x_1+(x_2-x_1)t$
• $y=x_1+(y_2-y_1)t$
• $z=z_1+(z_2-z_1)t$