I have several curves which I resample and turn on Curve U Attr and I like to group the points which are @curveu == 0. But in the group node if I toggle Expression on at the Base Group field only one point shows active. Expanding the String Value shows 1 and not all the points which are @curveu == 0.
If I visualize the curveu attr than I should get point ids like 0 27 54 81 108 135 162 189 …

Added hip file.

Thanks for the help.

Stephan

The “Base Group” field is a string parameter that's evaluated only once. In your HIP file, it's set to be evaluated as an HScript expression. @curveu isn't defined in HScript, so it seems to be defaulting to 0. 0 == 0 is true, so it evaluates to 1. That gets converted to the string 1 for the parameter, so Base Group is then just 1.

If you remove the expression and just put in the string @curveu==0, (see attached), it seems to work as expected, because the group parsing identifies @curveu==0 as something that it needs to evaluate as a group. This should work the same in other Group parameters as well. Hopefully that helps clear up the confusion!

Thank you for the clearing that up.

GREAT