[Sidefx-houdini-list] ray sop fetching attribute values thatdont exist.

Simon Barrick simon at primalpictures.com
Tue Feb 2 03:13:34 EST 2010


I've found it's only really reliable on triangulated geometry.
I believe that is because of the barycentric coordinates used to interpolate the values.
I even had problems on a regular mesh grid until I triangulated it first.


-----Original Message-----
From: sidefx-houdini-list-bounces at sidefx.com on behalf of Andrew D Lyons
Sent: Mon 01/02/2010 22:48
To: sidefx-houdini-list at sidefx.com
Subject: Re: [Sidefx-houdini-list] ray sop fetching attribute values thatdont exist.
 
How many samples are you using? Are you using "average Ray" as the
combiner?You may be averaging multiple samples to get 0.

If you play with some of those settings you may get more desirable
results. ie. 5 samples and "longest ray".

Cheers

On 1 February 2010 14:39, Robert Kelly <isstuff at gmail.com> wrote:
> I am wondering if the ray sop can be trusted....
>
> I have a ray sop fetching attributes from some geometry but sometimes
> it returns values that are not there to be returned.
>
> I have an int attribute called curve and it is on 7 tubes the
> attribute goes from 1 to 7 according to the curve that each tube was
> made from. The value is never zero. so i take that geometry append a
> attributeCreate set the curve int value to -1. I put it into the first
> input of a ray sop and the geometry before the attributeCreate into
> the second input; I set the bias so it dosen't just get the same point
> it came from... i set the ray sop to return the curve attribute that
> it hits and the dist value.
>
> So i am getting Zero for some of the curve attributes, there are
> plenty of -1 values for all the points that miss, and some values from
> 1-7 for others that hit but some have 0 as the value. What could cause
> this?
>
> Any ideas?
> Robert Kelly
> _______________________________________________
> Sidefx-houdini-list mailing list
> Sidefx-houdini-list at sidefx.com
> 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


______________________________________________________________________
This communication is from Primal Pictures Ltd., a company registered in England and Wales with registration No. 02622298 and registered office: 4th Floor, Tennyson House, 159-165 Great Portland Street, London, W1W 5PA, UK. VAT registration No. 648874577.

This e-mail is confidential and may be privileged. It may be read, copied and used only by the intended recipient. If you have received it in error, please contact the sender immediately by return e-mail or by telephoning +44(0)20 7637 1010. Please then delete the e-mail and do not disclose its contents to any person.
This email has been scanned for Primal Pictures by the MessageLabs Email Security System.
______________________________________________________________________


More information about the Sidefx-houdini-list mailing list