can't select diagonal of a grid with expression

[WLVL]

Hi Everyone!

 

I have a grid, i'd like to select the diagonal points.

Im using a group SOP, filter by expression: abs(TX) = abs(TZ);

The result is funky (does not select all "TX=-TZ" diagonal but only corner pts)

 

Any workarounds?

 

Thank you very much!!!

 

 

 

diagonal_select.hip

[konstantin magnus]

you can identify 'diagonal' points in a pointvop, as well.

grid_diag.hiplc

[mestela]

Huh, you're right, looks like a subtle rounding error with absolute and the if statement. Happens in your setup too konstantin if you put an abs vop on each wire before the equality test.

 

Might be worth sending to sidefx support a a bug.

 

In the interim, you can make it work if you subtract one from the other, and test if its within a very small range. Eg, for the group expression:

if( abs($TX)-abs($TZ)<0.0001  && abs($TX)-abs($TZ)>-0.001, 1 ,0 )

Or directly in a wrangle (slightly easier to read I reckon) :

 

float diff = abs(@P.x)-abs(@P.z);
float max = 0.001;
float min = -max;

if (diff<max && diff>min) {
  @Cd={1,0,0};
  @group_group1=1;
}

[WLVL]

Thank you very much!!

 

PS.sorry for the late response, i didnt realize the post was answered!

Edited October 29, 2015 by WLVL