when i want delte groups by the group center, i found two way: copy_stamp and foreach, but both way are too slow,is there other methord to do it?

here is a hip showing what i want!

Is this what you are after?

You can use a primitive attribute prim(“../mountain1”, $PR, “P”, 0) which, according to the help, provides the X component of the centroid (or the barycenter, not sure, see this post: http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=19407 [sidefx.com] )

After that just a delete sop and it is waaay faster than copy-stamping and for eaches

Pagefan
Is this what you are after?

You can use a primitive attribute prim(“../mountain1”, $PR, “P”, 0) which, according to the help, provides the X component of the centroid (or the barycenter, not sure, see this post: http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=19407 [sidefx.com] )

After that just a delete sop and it is waaay faster than copy-stamping and for eaches

thank you for your reply,but $PR finds every prim value, what i need is each group's value

what about this?
precomputing Group Center as Primitive attribute before mountain SOP
so the foreach or copy will process only once
then after mountain delete by this attribute

it will work for your example since mountain is not moving pieces in X but if you
want centers to update according to deformation you'll probably need other solution like:

creating points for each group center, then deform, then delete groups whose corresponding point meets the criteria

look at the attached file for both methods
they are realtime now (after a few seconds of waiting for preprocess)

tamte
what about this?
precomputing Group Center as Primitive attribute before mountain SOP
so the foreach or copy will process only once
then after mountain delete by this attribute

it will work for your example since mountain is not moving pieces in X but if you
want centers to update according to deformation you'll probably need other solution like:

creating points for each group center, then deform, then delete groups whose corresponding point meets the criteria

look at the attached file for both methods
they are realtime now (after a few seconds of waiting for preprocess)

thank you very much!
it's helpful for me