[Closed] Deleting user property?

You can get and set the complete UserPropBuffer string and perform operations on it.
Since it is just a large string with a new line for each property, it should be as simple as either using a stringStream and readLine() to collect all lines, check against your properties and skip those you want to delete, then build a new string from the remaining lines (VRay for example uses that buffer for render properties, so clearing everything is usually a bad idea) and assigning the new string to the buffer.
Alternatively, get the buffer, call (filterString theBuffer “
“) to create an array of all properties, loop through the array and collect only the ones you want to keep into a string delimited with “
“, then assign that string back to the buffer.

denisT posted a function for it here a few months back.

-Eric

I had similar case where i needed to check for invalid user props and add and delete some properties. What I did was that I used [font=Verdana]getUserPropBuffer()-method to get whole property buffer into a string and then I just parsed it to my own structs. Then I had whole buffer neatly organized and I could easily check for valid entries and possibly fix them. After everything was checked, I just created new buffer string based my structs and put whole buffer back to node using setUserPropBuffer(). I dont know if parsing buffer string is best way in your case, but in my case it was only reasonable method I could figure out. [/font]

If you’re just setting a short term string var on the object, consider AppData… Especially if you expect to execute on large scenes as it’s way faster…

(
start = timeStamp()
for g in geometry do setappdata g 79901 "My Value"
end = timeStamp()
format "AppData Processing % nodes took % seconds
" geometry.count ((end - start) / 1000.0)

start = timeStamp()
for g in geometry do  setUserProp g "My Att" "My Value"
end = timeStamp()
format "SetUserProp Processing % nodes took % seconds
" geometry.count ((end - start) / 1000.0)
)

AppData Processing 2000 nodes took 0.015 seconds
SetUserProp Processing 2000 nodes took 0.047 seconds

Clean up’s is real easy and fast too.

for g in geometry do deleteAppData g 79901

The ‘79901’ is an arbitrary value I’ve selected for the demo code, check the MSX help file for more info on this…

“Access to MAXWrapper AppData [left]
NOTE:
[/left]
[left][i]The AppData is stored in the scene file only if its object is in the scene—if, for example, you create a material in MAXScript and do not assign it to any object or the material editor, it will not be saved in the scene file nor will its AppData.

[/i]Access to MAXWrapper AppData[left]If you want to associate certain AppData strings with the scene as a whole, it is recommended that you create a hidden dummy node with a unique name and attach the scene AppData to that node.”
[/left]
[left]

[/left]
so what if i merge nodes ?
is that why it´s good to use a ‘hidden node’ to store AppData ?
[/left]
[left]
[/left]

AppData might be used with any MAXObject including nodes, modifiers, materials, controllers, etc.

if you merge any MAXObject to the scene it will be merged with its appData
[/left]

One thing to note if you copy an object the copy doesn’t have any copied appdata in it.

-Johan

denise’s function works great, thanks a lot