group object for only one frame

[SpencerL]

I have a group DOP that brings in objects based on its color using the expression

if(prim($OBJID, 0, "Cd", 0)>0, 1, 0)

What I need is for the object to only be in the group for one frame and then be dropped out of the group. I could also do what I need to do by starting a "counter" once the object is in the group. Im just not sure how to do this in DOPs. If this were in POPs, I would assign the group an attribute called "count" and set the value to be $COUNT + 1. I can then use the count value to activate/deactivate values. I cant seem to figure out how to do this in DOPs. Any suggestions appreciated.

Thanks!

Edited August 10, 2009 by SpencerL

[bhaveshpandey]

I'm not sure but can we make a custom global variable or add an attrib to be the on particular frame you need..and then group it using that attrib? (i havent really tried anything like this )

edit: if attribs dont work..can we use a custom global variable instead?

Edited August 11, 2009 by bhaveshpandey

[SpencerL]

I'm not sure but can we make a custom global variable or add an attrib to be the on particular frame you need..and then group it using that attrib? (i havent really tried anything like this )

edit: if attribs dont work..can we use a custom global variable instead?

Well, Im sure something like that would work if all the objects entered the group at the same frame, but in my case my objects are entering the group at different frames. Once the enter it, I only want them to be in the group for a single frame. Again, if there is a way start a counter on the frame the object enters the group, that would be enough for me.

[mrice]

Maybe this is something you could do using two groups?

dop_timestep_grp1.hipnc

[SpencerL]

Maybe this is something you could do using two groups?

I ended up doing a SOP based solution so that the object is only "red" for one frame, but your idea looks like it could work as well. Thanks!