[Sidefx-houdini-list] pcfilter point number

Olex P hoknamahn at gmail.com
Fri Aug 5 06:15:50 EDT 2011


Hi Nick,

That point cloud solution is simplest ever and most efficient (as it
samples just 1 point). And a setup is just one VEX (or VOP if you
want) operator. I would upload a hip file but I don't know any
pastebin like service that supports bin files.

On Fri, Aug 5, 2011 at 10:56 AM, Nick Zutphen <nvanzutphen at live.com> wrote:
> Hi Oleg,
>
> Thank you your your reply.
> I guess you're describing a similar approach to the one I mentioned in my first message.
>
> Initially I found it a rather complicated solution which I tend to avoid, especially in VOP's, that's why I tried to use pcfilter. It turned out that  'Attribute Transfer' works perfectly in this case.
>
> Cheers!
> Nick van Zutphen
>
> ----
> http://www.nickvanzutphen.com
>
>
>
>
>
>
>
>
>
> On Aug 4, 2011, at 11:35 AM, Olex P wrote:
>
>> Hi guys,
>>
>> Hi guys, the first entry in a point cloud lookup is always a nearest
>> point. A following snipet of code will give you the number of nearest
>> point and a distance to it
>>
>> [code]
>> sop
>> pcnearest(string       pcfile  = "";
>>                float        radius = 1.0f;
>>
>>                export int   num = -1;
>>                export float dist  = -1.0f)
>> {
>>    int handle = pcopen(pcfile, "P", P, radius, 1);
>>
>>    if(pciterate(handle))
>>    {
>>        pcimport(handle, "point.number",   num);
>>        pcimport(handle, "point.distance", dist);
>>    }
>>
>>    pcclose(handle);
>> }
>> [/code]
>>
>> On Wed, Aug 3, 2011 at 9:14 PM, Alvaro Castaneda <varomix at gmail.com> wrote:
>>> I think you're trying to do something more complex than it need to be
>>> we get sometimes caught in that, but always the best thing is a simple
>>> solution
>>> simple to develop and simple to use.
>>>
>>> Cheers
>>>
>>>
>>>
>>> 
>>>
>>>  *.:varomix:.*
>>> MIX Studio
>>> 3D Artist/Generalist TD
>>> www.varomix.net
>>>  My profiles: [image: LinkedIn] <http://www.linkedin.com/in/varomix> [image:
>>> Twitter] <http://twitter.com/varomix> [image:
>>> Facebook]<http://www.facebook.com/varomix>
>>> On Wed, Aug 3, 2011 at 2:00 PM, Nick van Zutphen <nvanzutphen at live.com>wrote:
>>>
>>>> @ Andrew
>>>> Ghehe, well with all due respect but your solution, compared to what I was
>>>> doing, is almost ridiculous due to its simplicity. But I like it! :-). It
>>>> works perfectly. Thanks a lot.
>>>>
>>>> @Mike
>>>> I have to keep this in mind because I'm pretty sure I'll run in to this one
>>>> again. Pcfilter works perfect if you would like to get position of 1 or
>>>> especially an average of multiple points, to bad it doesn't do the trick in
>>>> this case. Thank you for your input, it's much appreciated. Though Andrews
>>>> solution is, in this particular case, the way to go.
>>>>
>>>> Case closed, (with that paper file and red 'case closed' stamp on it ;-)
>>>> Nick van Zutphen
>>>> ------------------------------**--------------------
>>>> From: "Andrew Lyons" <tstexture at gmail.com>
>>>> Sent: Wednesday, August 03, 2011 9:12 PM
>>>>
>>>> To: <sidefx-houdini-list at sidefx.**com <sidefx-houdini-list at sidefx.com>>
>>>> Subject: Re: [Sidefx-houdini-list] pcfilter point number
>>>>
>>>>  Not totally clear on the problem - but I've always used the attribTransfer
>>>>> SOP to get near points:
>>>>>
>>>>> 1./ Create custom point "ptnum" int attr. Store $PT in there.
>>>>> 2./ attrTransfer ptnum to new geometry. (Set "Max Sample Count" set to 2
>>>>> if
>>>>> feeding same SOP into both inputs. Set to 1 otherwise.)
>>>>>
>>>>> Cheers
>>>>>
>>>>> On 3 August 2011 11:32, <mdunkley at gmail.com> wrote:
>>>>>
>>>>>  Hey Nick -
>>>>>>
>>>>>> I've had some fiddly problems using pcfilter for point numbers in the
>>>>>> past.
>>>>>> I was attempting to create a float point number variable called ptnum and
>>>>>> just look it up with no interpolation (ie 1 point lookup) from pcfilter,
>>>>>> but
>>>>>> even then i would often get incorrect values - I think the filter is
>>>>>> doing
>>>>>> some kind of filtering no matter what. Sometimes the ptnum value it
>>>>>> returned
>>>>>> would just be a number off, as if it was getting ceil'ed or floor'ed,
>>>>>> some
>>>>>> times it came back with a floating point component, so clearly there was
>>>>>> some sort of interpolation happening.
>>>>>>
>>>>>> I can say for sure that the other method you mentioned *does* work.
>>>>>> Pciterate doesn't really do anything on its own - you need it to feed a
>>>>>> while loop (both ouside the loop, and then again on the inside). Within
>>>>>> the
>>>>>> while, you can then use pcimport with "point.number" / "point.distance"
>>>>>> to
>>>>>> pull all that info out. My impression of pcfilter is that its just a
>>>>>> quick
>>>>>> and dirty one-stop-shop way to slew values between points, not to
>>>>>> intended
>>>>>> to work with the other point cloud functions - if you need to do anything
>>>>>> very specific you'll have to roll your own with pciterate and a while
>>>>>> loop.
>>>>>>
>>>>>> If you haven't seen it, check out peter quint's point cloud videos on
>>>>>> vimeo
>>>>>> - the second one talks very specifically about some of the issues related
>>>>>> to
>>>>>> making your own:
>>>>>> http://vimeo.com/9108284
>>>>>>
>>>>>> Best,
>>>>>> Mike
>>>>>>
>>>>>>
>>>>>>
>>>>>> On , Nick van Zutphen <nvanzutphen at live.com> wrote:
>>>>>>
>>>>>>  I like to stay close to 'SESI' guidelines, or like the default tools
>>>>>>> work
>>>>>>> (something I inherited from my intenship). I guess giving a position
>>>>>>> vector,
>>>>>>> which can also be set by using a handle is pretty close to that.
>>>>>>> Obviously
>>>>>>> using a sphere would work, but it's not very neat, is it?
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>  Cheers,
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Nick van Zutphen
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>  ------------------------------****--------------------
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  From: "Alvaro Castaneda" varomix at gmail.com>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Sent: Wednesday, August 03, 2011 6:21 PM
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  To: sidefx-houdini-list at sidefx.com****>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Subject: Re: [Sidefx-houdini-list] pcfilter point number
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>  This might be a dumb idea, but why don't you
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  ask the user to place a sphere for initial position
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  use that to grab any points inside and start from there?
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>  I can use that :)
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>  
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>  *.:varomix:.*
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  MIX Studio
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  3D Artist/Generalist TD
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  www.varomix.net
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  My profiles: [image: LinkedIn] http://www.linkedin.com/in/****varomix<http://www.linkedin.com/in/**varomix>
>>>>>> <http://www.linkedin.**com/in/varomix<http://www.linkedin.com/in/varomix>
>>>>>>>>
>>>>>>
>>>>>>> [image:
>>>>>>>
>>>>>>>
>>>>>>  Twitter] http://twitter.com/varomix> [image:
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> Facebook]http://www.facebook.****com/varomix<http://www.**
>>>>>> facebook.com/varomix <http://www.facebook.com/varomix>>
>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  On Wed, Aug 3, 2011 at 10:06 AM, Nick van Zutphen nvanzutphen at live.com
>>>>>>
>>>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>  Hi!
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>  I finally figured out how this maillist thing works :-), at least I hope
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  so. It feels a bit like 'you're used to Internet, and you have to use
>>>>>> 'the
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  wire', telex or how ever it's called in English' ;-).
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>  I'm working on a tool which operates on scattered points and it needs a
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  starting point. I would like to give the user the ability to specify a
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  position vector and the tool will figure out what the closest point is.
>>>>>>
>>>>>>> This
>>>>>>>
>>>>>>>
>>>>>>  becomes need when you would like to start in a certain area and the
>>>>>> points
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  might change due to a different seed or what so ever.
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>  I think of a pointcloud method, however I'm interested in the closest
>>>>>>
>>>>>>> point
>>>>>>>
>>>>>>>
>>>>>>  pointnumber. I know pciterate has the option point.number but that
>>>>>> doesn't
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  seem to work on pcfilter and ptnum doesn't give any luck either. I would
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  like to use pcfilter since it's about a single point and iterating over
>>>>>> 1
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  point doesn't seem to make much sense.
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>  So my question is: 'Is there a way to get the point number when using
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  pcfilter. If not, what's the alternative?'
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>  Cheers!
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Nick van Zutphen
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  ______________________________****_________________
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Sidefx-houdini-list mailing list
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Sidefx-houdini-list at sidefx.com
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> https://lists.sidefx.com:443/****mailman/listinfo/sidefx-****
>>>>>> houdini-list<https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list>
>>>>>> <https://lists.**sidefx.com:443/mailman/**listinfo/sidefx-houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>  ______________________________****_________________
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Sidefx-houdini-list mailing list
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Sidefx-houdini-list at sidefx.com
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> https://lists.sidefx.com:443/****mailman/listinfo/sidefx-****
>>>>>> houdini-list<https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list>
>>>>>> <https://lists.**sidefx.com:443/mailman/**listinfo/sidefx-houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>  ______________________________****_________________
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Sidefx-houdini-list mailing list
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>  Sidefx-houdini-list at sidefx.com
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> https://lists.sidefx.com:443/****mailman/listinfo/sidefx-****
>>>>>> houdini-list<https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list>
>>>>>> <https://lists.**sidefx.com:443/mailman/**listinfo/sidefx-houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> ______________________________****_________________
>>>>>> Sidefx-houdini-list mailing list
>>>>>> Sidefx-houdini-list at sidefx.com
>>>>>> https://lists.sidefx.com:443/****mailman/listinfo/sidefx-****
>>>>>> houdini-list<https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list>
>>>>>> <https://lists.**sidefx.com:443/mailman/**listinfo/sidefx-houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> ==============================**=========
>>>>> Andrew D Lyons | Digital Artist | http://www.tstex.com
>>>>> ==============================**=========
>>>>> ______________________________**_________________
>>>>> Sidefx-houdini-list mailing list
>>>>> Sidefx-houdini-list at sidefx.com
>>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>>
>>>>>  ______________________________**_________________
>>>>
>>>> Sidefx-houdini-list mailing list
>>>> Sidefx-houdini-list at sidefx.com
>>>> https://lists.sidefx.com:443/**mailman/listinfo/sidefx-**houdini-list<https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list>
>>>>
>>> _______________________________________________
>>> Sidefx-houdini-list mailing list
>>> Sidefx-houdini-list at sidefx.com
>>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>>
>> _______________________________________________
>> Sidefx-houdini-list mailing list
>> Sidefx-houdini-list at sidefx.com
>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>
> _______________________________________________
> Sidefx-houdini-list mailing list
> Sidefx-houdini-list at sidefx.com
> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>



More information about the Sidefx-houdini-list mailing list