How can i draw a grid diagram using 3D surface

[yanan]

I want to draw a grid, the size is 3x3(for x and y axis), however i got a result of 4x4.
Here is the example code: https://codepen.io/Yanan-Liu-the-sans/pen/dyBpBYV

Is there any way i can draw the gird to 3x3?

[AIMPED]

Hey @yanan , welcome to the forums.

I’m not sure I understand. You want to divide the edge in 3 equal distances. Therefore, you need to create two additional points.

Is that correct?

[yanan]

Thanks for reply this question, let me clarify it：