Group Expression Problem: Works for Some Primitive Only

[knightist]

Hi guys,

I have been running into this issue for a few times now and I really need help on this. The group Expression or sometimes even in VEX my group is not selecting all geometry intended, see image below.

See how primitive 159 is not selected even it has N val of {1,0,0}

I also attached a hip file as example.groupexpression.hip

[animatrix]

Hi,

It could be a precision issue, so might have to use some tolerance.

[knightist]

25 minutes ago, animatrix said:

Hi,

It could be a precision issue, so might have to use some tolerance.

ahh i see...but how did it happen tho? All i did was moving some points by index, there shouldn't be a precision problem

Edited March 16, 2022 by knightist

[animatrix]

I have to inspect the actual geo you have. Can you post your hip file please?

[eikonoklastes]

What happens if you try to use a Group node, set to Keep by Normals?

[knightist]

On 3/17/2022 at 10:40 AM, animatrix said:

I have to inspect the actual geo you have. Can you post your hip file please?

Hi Yunus, I already attached the hip file it's right above my first image. Sorry should've put it at the bottom so it's more obvious

[knightist]

On 3/17/2022 at 2:56 PM, eikonoklastes said:

What happens if you try to use a Group node, set to Keep by Normals?

it works surprisingly well when I set the direction to 1,0,0 and spread angle to 0. It didn't miss any primitive. But it is just frustrating that my groupexpression is set to @N==set(1,0,0) as well, yet it won't group all my prim

[animatrix]

Using the same code in a primitive wrangle yields the same result as Group Expression SOP is doing the same but when I change the VEX code to this it works:

if ( @N.x > 0.99999 && @N.y == 0 && @N.z == 0 )
    i@group_prims = 1;

You can use this in the Group Expression SOP:

@N.x > 0.99999 && @N.y == 0 && @N.z == 0