[Sidefx-houdini-list] vops and point clouds

Olex P hoknamahn at gmail.com
Thu Aug 20 07:48:40 EDT 2009


Humm, I made a test but for some reason I see the clipping that you have on
your screenshot. The rest seems to be fine.
Have to check what exactly causes that clipping.

On Thu, Aug 20, 2009 at 12:33 PM, Olex P <hoknamahn at gmail.com> wrote:

> Hi Nicholas,
>
> I believe all what you need is just go through all the points in radius and
> sum all the values of alpha on them. The order doesn't really matter.
>
>
> On Thu, Aug 20, 2009 at 11:54 AM, Nicholas Pliatsikas <
> nick_p102 at hotmail.com> wrote:
>
>>
>> Didnt realise the refract limits would affect the point cloud data. I will
>> check into that.
>>
>> I had a good think about what was causing the problems last night, I think
>> its due to how a random ID variable is working in relation to the order in
>> which the point cloud data is being seached.
>>
>> For example if the current points random ID value is bigger then the
>> random ID value of the next point it will be ignored, that point will be
>> ignored. I guess what is really needed is some way of sorting the point
>> datas random ID values then bring those in sequential. But I have a feeling
>> thats not possible at all. So im trying another approach, and changing the
>> order of where the random call is happening, i.e clipping it with the alpha
>> map then running the if statement to check what the highest visible layer
>> is.
>>
>> This is much tricker then i first thought..
>>
>> Cheers
>> Nick
>>
>> > Date: Wed, 19 Aug 2009 09:40:51 -0700
>> > From: daveinengland at gmail.com
>> > To: sidefx-houdini-list at sidefx.com
>> > Subject: Re: [Sidefx-houdini-list] vops and point clouds
>> >
>> > I can't get to the files you referenced because of our firewall, but
>> have
>> > you checked the refract limit on your objects? If this is too low, the
>> rays
>> > will be limited by this. Also, there is the opacity limit in the ROP may
>> be
>> > limiting your rays.
>> >
>> > Just a thought.
>> >
>> > Dave
>> >
>> > On Wed, Aug 19, 2009 at 2:25 AM, Nicholas Pliatsikas
>> > <nick_p102 at hotmail.com>wrote:
>> >
>> > >
>> > > Hey guys and gals.
>> > >
>> > > After doing a good bit of work on the point cloud shader ive hit a
>> problem.
>> > > To me it seems that there is some optimisations happening with the
>> point
>> > > cloud data or its just a bug with code/mantra .
>> > >
>> > > Basically when layering the point cloud circles it looks as if mantra
>> is
>> > > cutting out much of the underlying circles, creating a problem when
>> layering
>> > > images using alphas. i.e parts of the underlying images are cut off.
>> > >
>> > > I can't see a problem with the code i added, so I went back to the
>> example
>> > > Olex sent me and changed it to be additive. This illustrated the same
>> issue.
>> > > You can see a screen grab here
>> > >
>> > > https://rcpt.yousendit.com/727895459/45f82a647fbe6eae52df9dc836f604f3
>> > >
>> > > If it is a bug/limit with mantra I wills end this off to sidefx
>> support.
>> > >
>> > > I have also saved out the additive version of the hipfile, you can
>> download
>> > > it here.
>> > >
>> > > https://rcpt.yousendit.com/727894133/de680b2c71c2c8d61f6dc0700d9d57a4
>> > >
>> > > I hope this is something we can get around as it will be a really nice
>> way
>> > > to add controlled details to scene. Just a note it also seems as if
>> there is
>> > > the odd point radius that isnt being added correctly either (the green
>> > > circles at the bottom right of the screen for example)
>> > >
>> > > Cheers
>> > > Nick
>> > >
>> > > > From: nick_p102 at hotmail.com
>> > > > To: sidefx-houdini-list at sidefx.com
>> > > > Date: Fri, 14 Aug 2009 15:55:02 +0000
>> > > > Subject: Re: [Sidefx-houdini-list] vops and point clouds
>> > > >
>> > > >
>> > > > Thanks for that Olex :) thats a great example, I see what you where
>> > > meaning in your code about using the maxheight random calls. Just
>> trying
>> > > this out in vops, having some oddities but will try a few more times
>> until i
>> > > resort to vex coding ;¬) as i need to quite abit inside that loop.
>> > > >
>> > > > Cheers mucho!!!
>> > > > Nick
>> > > >
>> > > >
>> > > >
>> > > > > Date: Fri, 14 Aug 2009 13:46:49 +0100
>> > > > > From: hoknamahn at gmail.com
>> > > > > To: sidefx-houdini-list at sidefx.com
>> > > > > Subject: Re: [Sidefx-houdini-list] vops and point clouds
>> > > > >
>> > > > > Oops, that was toooo quick test. There is correct one
>> > > > >
>> > > > >
>> > >
>> http://www.hotmail.ru/download.php/?file=:pcdvd2.hip&host=alex-hawk.hotmail.ru/flashcard&user=alex-hawk&lng=ru
>> > > > >
>> > > > > On Fri, Aug 14, 2009 at 1:33 PM, Olex P <hoknamahn at gmail.com>
>> wrote:
>> > > > >
>> > > > > > Hey,
>> > > > > >
>> > > > > > There is a quick example
>> > > > > >
>> > > > > >
>> > > > > >
>> > >
>> http://www.hotmail.ru/download.php/?file=:pcdvd.hip&host=alex-hawk.hotmail.ru/flashcard&user=alex-hawk&lng=ru
>> > > > > >
>> > > > > > AA isn't included! :p
>> > > > > >
>> > > > > >
>> > > > > > On Fri, Aug 14, 2009 at 12:24 PM, <eetu at iki.fi> wrote:
>> > > > > >
>> > > > > >> >> >> Hey Peoples
>> > > > > >> >> >>
>> > > > > >> >> >> Im currently working on an image bombing point cloud
>> shader
>> > > and hit
>> > > > > >> a
>> > > > > >> >> >> problem i dont quite understand how to solve.
>> > > > > >>
>> > > > > >> Here's a thread from Georg which might well be relevant for you
>> > > > > >>
>> > > > > >>
>> > > > > >>
>> > >
>> http://forums.odforce.net/index.php?/topic/6967-a-shader-each-day/page__view__findpost__p__47148
>> > > > > >>
>> > > > > >> I vaguely remember another forum thread with someone battling
>> with
>> > > the
>> > > > > >> same problem, but can't find it now for the life of me. I think
>> it
>> > > was
>> > > > > >> about overlapping fakeshadow blobs, if you happen to be able to
>> find
>> > > it :)
>> > > > > >>
>> > > > > >> eetu.
>> > > > > >>
>> > > > > >>
>> > > > > >> _______________________________________________
>> > > > > >> 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
>> > > >
>> > > > _________________________________________________________________
>> > > > Celebrate a decade of Messenger with free winks, emoticons, display
>> pics,
>> > > and more.
>> > > > http://clk.atdmt.com/UKM/go/157562755/direct/01/
>> > > > _______________________________________________
>> > > > Sidefx-houdini-list mailing list
>> > > > Sidefx-houdini-list at sidefx.com
>> > > > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>> > >
>> > > _________________________________________________________________
>> > > Windows Live Messenger: Celebrate 10 amazing years with free winks and
>> > > emoticons.
>> > > http://clk.atdmt.com/UKM/go/157562755/direct/01/
>> > > _______________________________________________
>> > > 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
>>
>> _________________________________________________________________
>> Windows Live Messenger: Celebrate 10 amazing years with free winks and
>> emoticons.
>> http://clk.atdmt.com/UKM/go/157562755/direct/01/
>> _______________________________________________
>> 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