[Sidefx-houdini-list] Procedural primitive group deletion

Antoine Durr antoine at floqfx.com
Wed Feb 18 18:36:19 EST 2009


On Feb 18, 2009, at 3:23 PM, eetu at iki.fi wrote:

> Or, just put a Delete SOP inside the foreach loop, with expression  
> set to
> nprims("../each1") < 20   :)

Yeah, I guess that would be a whole bunch easier, wouldn't it!

-- Antoine

>
> (Only the current group's geometry exists inside each loop iteration)
>
> eetu.
>
>
>> I would add a prim float attribute to the whole geometry, set it to
>> 1.0; then do a foreach SOP, go by groups; attribpromote that float
>> prim attribute to a detail attribute, using 'sum', which will add up
>> all the 1.0's and give you your prim count in that chunk; then delete
>> the whole thing if below threshold before delivering it to the
>> 'foreach'.
>>
>> I was also thinking about another approach involving the hasprim()
>> and primlist() functions, e.g. args(primlist("../previousSOP",
>> pieces_0)) would give you the prim count of pieces_0, but I couldn't
>> think of a way to get an answer to "if I am primitive 4, how do I get
>> the answer to 'what group am I in'".  If I could, i.e. if I knew that
>> primitive 4 was in pieces_3, then you could do the args(primlist 
>> ()) gag.
>>
>> -- Antoine
>>
>> On Feb 18, 2009, at 2:50 PM, Rick Fuentealba wrote:
>>
>>> Hey gang,
>>>
>>> I'm looking for a way to delete primitive groups that have a  
>>> specified
>>> number of primitives in the group.
>>> For example:
>>>
>>> 10 Primitive Groups:
>>>    114 primitives in pieces_0
>>>     88 primitives in pieces_1
>>>     50 primitives in pieces_2
>>>     27 primitives in pieces_3
>>>    141 primitives in pieces_4
>>>      8 primitives in pieces_5
>>>    117 primitives in pieces_6
>>>    160 primitives in pieces_8
>>>      2 primitives in pieces_7
>>>    129 primitives in pieces_9
>>>
>>> So now say I want to have the the groups with less than 10  
>>> primitives
>>> deleted, in this case 5 and 7.
>>>
>>> Anyone have a method for this?
>>>
>>> Thanks,
>>> Rick
>>> _______________________________________________
>>> Sidefx-houdini-list mailing list
>>> Sidefx-houdini-list at sidefx.com
>>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>
>> -- Antoine
>>
>> Antoine Durr
>> Floq FX Inc.
>> 10659 Cranks Rd.
>> Culver City, CA 90230
>> 310/430-2473
>>
>>
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>>
>
>
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-- Antoine

Antoine Durr
Floq FX Inc.
10659 Cranks Rd.
Culver City, CA 90230
310/430-2473





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