My undestanding of the first condition is: the projection of **o** to **x** on the direction **d** should be between $t_0$ and $t_1$. But I don't understand how to get the second condition. Can anyone help me? <img width="585" alt="image" src="https://user-images.githubusercontent.com/12771564/225605699-651b11ef-a458-4411-bf95-f12c53c29239.png">
My undestanding of the first condition is: the projection of o to x on the direction d should be between$t_0$ and $t_1$ .
But I don't understand how to get the second condition. Can anyone help me?
