How to add a Group field to my OPs that's found in the standard SO

[magneto]

I am talking about the Group field that allows you to type into but also have a drop down where Houdini provides you with all the available groups.

Is it possible to have the same control in custom OPs/DAs so I can limit my OP to a particular group?

Thanks

Edited December 25, 2011 by magneto

[graham]

Depending on what you are doing you can usually get that information for free. If your asset has nodes internally that need to accept a group and have the normal prim/point Group parameter with the menu, the easiest thing to do is to just promote that parameter directly to your asset. It will create a String menu parameter that has its menu script using opmenu -l and pointing to that node/parameter. This basically asks that group parm for its contents and displays it up one level.

However, if you are using something that doesn't have that (say a Python SOP), you'll have to build the menu yourself by doing something like this in the menu script section of the parameter:

sopnode = hou.pwd()
# List of tokens/labels to return.
menu = []
# Make sure there is an input node before asking for its geometry.
if sopnode.inputs():
    # Optionally add in '*' for all groups.
    menu.extend(("*", "*"))
    geo = sopnode.inputs()[0]
    for group in geo.pointGroups():
        name = group.name()
        menu.extend((name, name))

return menu

Edited December 25, 2011 by graham

[TheUsualAlex]

Still checking the net while on vacation???

(ahem.. shame on me)

Edited December 25, 2011 by TheUsualAlex

[magneto]

Depending on what you are doing you can usually get that information for free. If your asset has nodes internally that need to accept a group and have the normal prim/point Group parameter with the menu, the easiest thing to do is to just promote that parameter directly to your asset. It will create a String menu parameter that has its menu script using opmenu -l and pointing to that node/parameter. This basically asks that group parm for its contents and displays it up one level.

However, if you are using something that doesn't have that (say a Python SOP), you'll have to build the menu yourself by doing something like this in the menu script section of the parameter:

sopnode = hou.pwd()
# List of tokens/labels to return.
menu = []
# Make sure there is an input node before asking for its geometry.
if sopnode.inputs():
    # Optionally add in '*' for all groups.
    menu.extend(("*", "*"))
    geo = sopnode.inputs()[0]
    for group in geo.pointGroups():
        name = group.name()
        menu.extend((name, name))

return menu

Thanks Graham, just tried it but got no attribute called pointGroups on geo. Do I have to create an attribute with that name? I assume it's not the name of the parameter of my group control, right?

Still checking the net while on vacation???

(ahem.. shame on me)

No vacation for the wicked

[graham]

My bad. It should be this for the 8th line:

geo = sopnode.inputs()[0].geometry()

[magneto]

Thanks Graham, that's awesome. I just tried it, the menu at least pop-ups, but doesn't show any groups that I created upstream? Do I have to add in more code for that?

Also I assume in the code I will have to get the name of the menu item clicked and set the text of the textbox to this value?

Lastly how can I read this value back from the textbox? Is there a single function that can get points/prims whether the user typed in point/prim indices or a group name or just *, etc?

Thanks again