[Sidefx-houdini-list] Rendering boxes with cusped edges anddisplacements

Sean Lewkiw Sean.Lewkiw at cis-vancouver.com
Wed Aug 24 13:49:34 EDT 2011


Hm, that did something interesting, I'll keep investigating but it looks promising.

I created the att that stored the smooth N, added the cusped vertex N, used my att as the N input in "displace along N VOP" with "ensure proper smooth shading" turned off, then added a "shading N" vop after the N output.  I get displacement, cusped edge, and no tearing.

Sean



-----Original Message-----
From: sidefx-houdini-list-bounces at sidefx.com [mailto:sidefx-houdini-list-bounces at sidefx.com] On Behalf Of Mark Elendt
Sent: Wednesday, August 24, 2011 9:23 AM
To: sidefx-houdini-list at sidefx.com
Subject: Re: [Sidefx-houdini-list] Rendering boxes with cusped edges anddisplacements

The reason this happens is that you're likely displacing along the
normal.  Since the normals aren't smooth across the polygons, you end
up with a discontinuity (leading to cracks).

You might try creating a separate point attribute to represent the
smooth normals and using that to displace (rather than the shading
normal).

Hope that makes some kind of sense.

P.S.  Even with vertex normals, you'll get discontinuities in the displacement.

On Wednesday Aug 24 at 09:09, Sean Lewkiw wrote:
> Thanks for the suggestions guys... this does indeed work (subd or polybevel) but it is not a practical solution in my case because I have tens of thousands of these boxes to deal with.
>
> Sean
>
>
>
> -----Original Message-----
> From: sidefx-houdini-list-bounces at sidefx.com [mailto:sidefx-houdini-list-bounces at sidefx.com] On Behalf Of Phil Spicer
> Sent: Wednesday, August 24, 2011 1:42 AM
> To: sidefx-houdini-list at sidefx.com
> Subject: Re: [Sidefx-houdini-list] Rendering boxes with cusped edges anddisplacements
>
> Hi Sean,
>
> I gave the edges of the box a polybevel of 0.001 without cusping N, and it gave me a bumpy box with no teared edges. Not an ideal solution I know, but the noise passes through the edges in a pleasing way whilst retaining the overall box aesthetic. It is not quite as boxy as a sugar cube however it is not that far off.
>
> Kind regards,
>
> Phil.
>
>
>
>
>
>
> On 24 Aug 2011, at 03:39, Christopher Stewart wrote:
>
> > Sorry Sean, but this is great to hear. Thought I was just all
> > brainless and thumbs.
> >
> > I've been making all affected geometry sub-d's with hella-creased
> > corners. It fixes that and some other shading issues.
> >
> > Not any kind of real solution and hopefully somebody here knows the score...
> >
> > --
> > ----
> > Christopher Stewart
> > Vancouver, BC
> > 3D | VFX | IT
> >
> >
> >
> > On Tue, Aug 23, 2011 at 6:49 PM, Sean Lewkiw
> > <Sean.Lewkiw at cis-vancouver.com> wrote:
> >> I'm pulling my hair out trying to get this to work.
> >>
> >> I have a bog-standard box.  I apply a simple shader and render, I get smoothed edges.  Slap on a vertex sop, cusp N, I get faceted edges.  Good.
> >>
> >> Apply a displacement using simple turbulent noise in a simple "material shader builder" shader.  Now I get the sharp edges, but the displacement tears.  It looks the same as you get with a unshared points box, only there are no holes.... the holes are just filled with a streaked displacement.
> >>
> >> Uncusp the vertex N, it looks nice, but now I have interpolated normals and it no longer looks box-like and shades weirdly at edges.
> >>
> >> Am I asking for the moon on a stick to expect this to work?  I need the non-interpolated normals of the cusped version, without the tearing of the cusped version.
> >>
> >> Sean
> >>
> >>
> >>
> >>
> >>
> >> _____________________________________
> >> Sean Lewkiw | DFX Supervisor
> >> method studios vancouver || 50 West 2nd Ave | Vancouver BC | V5Y 1B3
> >> p. 604.874.8700 | f. 604.872.2106 | c. 6043461228
> >> sean.lewkiw at cis-vancouver.com
> >>
> >>
> >>
> >> This e-mail and any attachments are intended only for use by the addressee(s) named herein and may contain confidential information. If you are not the intended recipient of this e-mail, you are hereby notified any dissemination, distribution or copying of this email and any attachments is strictly prohibited. If you receive this email in error, please immediately notify the sender by return email and permanently delete the original, any copy and any printout thereof. The integrity and security of e-mail cannot be guaranteed.
> >> _______________________________________________
> >> 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
> >
> >
>
>
>
> This email is intended only for the person to whom it is addressed and may contain confidential information. If you have received this email in error, please notify the sender and delete this email, which must not be copied, distributed or disclosed to any other person.
> Any views or opinions presented are solely those of the author and do not necessarily represent those of Bournemouth University or its subsidiary companies. Nor can any contract be formed on behalf of the University or its subsidiary companies via email.
>
>
>
> _______________________________________________
> Sidefx-houdini-list mailing list
> Sidefx-houdini-list at sidefx.com
> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>
>
> This e-mail and any attachments are intended only for use by the addressee(s) named herein and may contain confidential information. If you are not the intended recipient of this e-mail, you are hereby notified any dissemination, distribution or copying of this email and any attachments is strictly prohibited. If you receive this email in error, please immediately notify the sender by return email and permanently delete the original, any copy and any printout thereof. The integrity and security of e-mail cannot be guaranteed.
> _______________________________________________
> Sidefx-houdini-list mailing list
> Sidefx-houdini-list at sidefx.com
> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list

--
Mark Elendt
_______________________________________________
Sidefx-houdini-list mailing list
Sidefx-houdini-list at sidefx.com
https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list


This e-mail and any attachments are intended only for use by the addressee(s) named herein and may contain confidential information. If you are not the intended recipient of this e-mail, you are hereby notified any dissemination, distribution or copying of this email and any attachments is strictly prohibited. If you receive this email in error, please immediately notify the sender by return email and permanently delete the original, any copy and any printout thereof. The integrity and security of e-mail cannot be guaranteed.


More information about the Sidefx-houdini-list mailing list