Am following old tutorial to create system where one object aim to another object but in this tutorial they are using null and has option of look at. but null in houdini 16 does'nt has one how can i create the look at,please help me.

Look At option is deprecated since Houdini 16.
It is invisible by default.
To bring it again just select and right click on your null then select Parameter and Channels then Edit Parameter Interface.
Underneath Existing Parameters check Show Invisible Parameters.
Now you should see all Look At options under Transform folder just select whichever you want and turn off Invisible option for them.

Hi,

Do remember to check out the new version though… You can either find the Look At shelf tool under the Contraints shelf and see what it puts down for you OR check the ‘Enable constraints’ toggle on the object you want to constrain, and then hit the far right button next the ‘Constraints’ field that pops up below. This will show a drop-down menu which you can select Look At from and then follow the instructions in the viewport.

thanks