Render Artifacts with XSI 7 / MR 3.6
Martin Weber
I have run into weird troubles with a couple of scenes I need to render.
I have separated a character into it's own passes and now have weird
rendering artifacts (see the streaks in the attached image).
I was using the render settings from the default pass. When I reset them
to default on the Optimization tab (most notably mesh splitting factor
to 1.0, primary rays to scanline) they did disappear for some frames but
resulted in artifacts in other frames and different streaks in most
frames that had artifacts before.
I am a bit puzzled now how to get rid of them. Naturally this all
happens when you have a tight deadline also. I cannot go back to XSI 6.5
as I set the whole project up in XSI 7 and also make use of ICE.
The artifacts are there regardless of rendering locally from the GUI,
commandline or remotely through batch.
The character is animated using PointOven caches.
Funnily though, when I render a separate reflection pass the artifacts
are gone (character is only visible to secondary rays there). Same is
true for a reflection matte pass. The alpha and raster motion channel
for the character pass also shows the same artifacts. Using raytracing
for primary rays in the character pass also did not help (see the
settings screengrab).
I would appreciate any help.
System is Vista 64bit, XSI 7 64-bit, MacPro 8-core Xeon, GeForce 8800 GT
Thanks,
-Martin
André Adam
Subdivision Surfaces which looks pretty much like the artifacts shown in
your images. Basically you get geometry streaks at random. Does this
scenario apply to your scene?
-André
> ------------------------------------------------------------------------
>
>
> ------------------------------------------------------------------------
>
---
Unsubscribe? Mail Majo...@Softimage.COM with the following text in body:
unsubscribe xsi
Stefan Andersson
change in the render settings (motion blur) can solve the problem. Or
go up a even higher SubD lever (3 or 4).
regards
stefan andersson
--
Stefan Andersson / vfx supervisor / Swiss International AB
S:t Eriksgatan 48 B / SE-11234 Stockholm / Phone: +46 8 662 24 60
christian keller
instead of normal ...
hm, they did not fix this bug :-(
---
André Adam
to be the only solution working for us.
-André
Frantisek Hradecky
Francesco.
kim aldis
settings for anything really. For that character, 0,2 or 1,2 and get the
threshold good and low.
> -----Original Message-----
> From: owne...@Softimage.COM [mailto:owne...@Softimage.COM] On
> Behalf Of Martin Weber
> Sent: 28 August 2008 14:02
> To: X...@Softimage.COM
> Subject: Render Artifacts with XSI 7 / MR 3.6
>
---
Harry Bardak
I have just finished a job when I got the same issue with 6.5
This bug is present only when you try to motion blur any point oven driven cache and when you subdivide the mesh at the rendertime.
workaround are :
- render only one frame per machine ( the first frame is ok, the second will have these spikes ) That can be problematic when you got scene that take more time to load than render.
- Remove any subdivision at rendertime and make physcal subdivision on your mesh ( local subdivision operator after point oven operators )
- Use another system of point cache than point oven.
It seams that there is a new point cache system with ICE but I am not sure.
I was stuck to 6.5 when 7 have been released
Harry Bardak
TD / Compositor.
Http://www.harrybardak.co.uk/+44 781 661 4147
----------------------------------------
> Date: Thu, 28 Aug 2008 15:02:05 +0200
> From: martin...@codesign.at
> To: X...@Softimage.COM
> Subject: Render Artifacts with XSI 7 / MR 3.6
>
_________________________________________________________________
News, entertainment and everything you care about at Live.com. Get it now!
http://www.live.com/getstarted.aspx
Martin Weber
Yes, render subdiv plus motion blur was the culprit. I am now using
local subdivision on the meshes and see what I can get from it. I need
the raster motion.
I have attached a quickly hacked script that I use now to apply the
local subdivision to all polymsh within my model. It's certainly not
foolproof but it does the job and allows me to change the subdiv level
of all polymsh in the model afterwards also. To use just select the
model or an object within and run. Change the settings in the call of
SetLocalSubdivision at the bottom.
Use at your own risk. Works for me but probably not for you ;) At least
I can apply local subdiv on top of the pointoven op this way.
Thanks for the help!
-Martin
kim aldis wrote:
> Purely an observation, 0,3 threshold 0.15 isn't a particularly good set of
> settings for anything really. For that character, 0,2 or 1,2 and get the
> threshold good and low.
Thanks Kim. Yeah I know. Had the settings remain from the default pass
which had some nasty stuff that could use anti-alias of 3 at times but I
did not want it to go there unless for high contrast areas. Anyways, not
really a good setting like you said. Still have many miles to go with
Mental Ray until I can pretend to know how to use it ;)
Cheers,
-Martin
Frantisek Hradecky
Votch
smooth UV's. If you character is textured this will cause all kinds of
wacky texture bending. The only method I've found to smooth the UV's
to match rendertime subdivision is to use the "Duplicate with
subdivision" command.
Votch
Martin Weber
Yes, so far it is not really noticable. I am rendering at PAL resolution
and so far have no real close ups. I actually wish there were some
options for the subdivision of UVs with geometry approximation as well.
The tools I use (XSI, Modo, Cinema 4D/Bodypaint) handle UV subdivision
quite differently - especially when dealing with UV island borders.
Cinema 4D/Bodypaint has a couple of different options for borders and
Modo can use subdivided or un-subdivided UVs. At least having these two
options would be great.
Cheers,
-Martin
Votch wrote:
> One thing to look out for, Local subdivision refinement does not
> smooth UV's. If you character is textured this will cause all kinds of
> wacky texture bending. The only method I've found to smooth the UV's
> to match rendertime subdivision is to use the "Duplicate with
> subdivision" command.
>
> Votch
---
Frank Lenhard
just point caches. i am quite shocked it did not got fixed, as it now
turns out that a lot of ppl have it happen...
ciao
franky
Thursday, August 28, 2008, 4:22:40 PM, you wrote:
HB> This bug is present only when you try to motion blur any point
HB> oven driven cache and when you subdivide the mesh at the rendertime.
Votch
Softimage knows about the issue and I believe they have identified the
source of the problem.
Consequently I've removed the use of render time subdivision from our
pipeline. It's kind of a drag but many render problems have now
disappeared. And even though the triangle count of models has
increased (by using local subdivsion), I've noticed a drop in render
time with motionblur. However I have yet to do any tests involving
displacement.
Votch Levi
Martin Weber
Too bad this seems true. I am now having the same problems with a
sequence where I applied a Local Subdivision operator above the
PO_Reader operator.
I noticed that the artefacts are related to the Deformation Motion Steps
in the mental ray Rendering settings. When I turn them down to 1 the
artefacts are gone.
See the attached image. At render subdivision I also do not get the
artefacts with deformation motion steps of 1.
If you have an idea how to fix the issue I really would appreciate it. I
cannot rendering .mi archives though as I only have XSI batch licenses.
Naturally deadline is in two days. Gonna see how to handle that :(
Thanks,
-Martin
Martin Weber
Just wanted to add: when I render a reflection pass with exact the same
settings the artifacts are gone. I was wondering if rendering through a
transparent plane would help as it would use secondary rays too but it
did not work.
Cheers,
-Martin
Votch
will still have problems with motionblur. Motion Blur is calculated
incorrectly when rendertime subdivision is enabled and moving
camera's.
The only solution I have found is to apply a local subdivision op as
you have. But make certain subdivison is set to 0 in the geometry
approximation editor. You may also have to render in groups of 1. This
is best accomplished via a script and XSIbatch or in a managed render
queue (deadline, royalrender, etc..)
Frank Lenhard
V> Even if you can get the "Poly distortion" artifacts to disappear you
V> will still have problems with motionblur. Motion Blur is calculated
V> incorrectly when rendertime subdivision is enabled and moving
V> camera's.
its the same with static cameras. actually i only got it with static
cams....
ciao
franky
Schoenberger
If it is not a problem in reflections, then it is seems to be rendered right with pure raytracing.
But you say you need the rasterizer option?
BTW: If you use transparent objects, then you still keep the rasterizer for the transparency.
Try raytracing only with low AA settings, just to check if the bug appears.
Holger Schönberger
technical director
The day has 24 hours, if that does not suffice, I will take the night
Frank Lenhard
and the artefacts just changed, when using raterizer, raytracing,
scanline, they never went away...
all this only happens when using 3d motion blur in any flavour...
ciao
franky
Tuesday, September 2, 2008, 12:52:47 PM, you wrote:
S> If it is not a problem in reflections, then it is seems to be
S> rendered right with pure raytracing.
S> But you say you need the rasterizer option?
S> BTW: If you use transparent objects, then you still keep the rasterizer for the transparency.
S> Try raytracing only with low AA settings, just to check if the bug appears.
S> Holger Schönberger
S> technical director
S> The day has 24 hours, if that does not suffice, I will take the night
S> |> -----Original Message-----
S> |> From: owne...@Softimage.COM [mailto:owne...@Softimage.COM] On Behalf Of Votch
S> |> Sent: Tuesday, September 02, 2008 2:50 AM
S> |> To: X...@Softimage.COM
S> |> Subject: Re: Render Artifacts with XSI 7 / MR 3.6
S> |>
S> |> Even if you can get the "Poly distortion" artifacts to disappear you
S> |> will still have problems with motionblur. Motion Blur is calculated
S> |> incorrectly when rendertime subdivision is enabled and moving
S> |> camera's.
S> |>
S> |> The only solution I have found is to apply a local subdivision op as
S> |> you have. But make certain subdivison is set to 0 in the geometry
S> |> approximation editor. You may also have to render in groups of 1. This
S> |> is best accomplished via a script and XSIbatch or in a managed render
S> |> queue (deadline, royalrender, etc..)
S> |>
S> |> On Mon, Sep 1, 2008 at 1:32 PM, Martin Weber
S> <martin...@codesign.at> wrote:
S> |> >
S> |> > Too bad this seems true. I am now having the same problems with a sequence
S> |> > where I applied a Local Subdivision operator above the PO_Reader operator.
S> |> >
S> |> > I noticed that the artefacts are related to the Deformation Motion Steps in
S> |> > the mental ray Rendering settings. When I turn them down to 1 the artefacts
S> |> > are gone.
S> |> >
S> |> > See the attached image. At render subdivision I also do not get the
S> |> > artefacts with deformation motion steps of 1.
S> |> >
S> |> > If you have an idea how to fix the issue I really would appreciate it. I
S> |> > cannot rendering .mi archives though as I only have XSI batch licenses.
S> |> > Naturally deadline is in two days. Gonna see how to handle that :(
S> |> >
S> |> > Thanks,
S> |> > -Martin
S> |> >
S> |> >
S> |> > Frank Lenhard wrote:
S> |> >>
S> |> >> here it also applied in 6.5 with normal enveloped characters, not
S> |> >> just point caches. i am quite shocked it did not got fixed, as it now
S> |> >> turns out that a lot of ppl have it happen...
S> |> >>
S> |> >> ciao
S> |> >> franky
S> |> >>
S> |> >>
S> |> >> Thursday, August 28, 2008, 4:22:40 PM, you wrote:
S> |> >>
S> |> >>
S> |> >>
S> |> >> HB> This bug is present only when you try to motion blur any point
S> |> >> HB> oven driven cache and when you subdivide the mesh at the rendertime.
S> |> >
S> |> >
S> |> ---
S> |> Unsubscribe? Mail Majo...@Softimage.COM with the following text in body:
S> |> unsubscribe xsi
S> ---
S> Unsubscribe? Mail Majo...@Softimage.COM with the following text in body:
S> unsubscribe xsi
Martin Weber
I tested a few frames with Raytracing for primary frames and the
problems were gone.
To be clear, we talk about two different artefacts in the meanwhile.
Streaks in renderings caused by render time subdivision (render geometry
approximation > 0) happen with raytracing also.
Spikey meshes happen with local subdivision applied and no render time
subdivision. These artifacts seem to be gone with raytracing primary rays.
Frank, not interrupting at all but providing pieces for my mental
picture of the issue. Thanks.
Thanks for all your answers guys. They helped me to understand the issue
a lot better. Its a nasty one but for now I know how to handle it even
if it is a royal PITA.
Cheers,
-Martin
--
Martin Weber - TD & CG Generalist, Software Developer
www.codesign.at - martin...@codesign.at
Skype: codesign.at
Mobile Phone: +43 676 844180300
Villach - Austria - Europe - Timezone: GMT+1(+DST)
Frank Lenhard
MW> Spikey meshes happen with local subdivision applied and no render time
MW> subdivision. These artifacts seem to be gone with raytracing primary rays.
do these only happen in conjunction with mblur? or do they happen all
the time with you? i never saw these here... just the blurry
streaks...
ciao
franky
Martin Weber
They happen with motion blur on. I did not test without as I need the
motion blur. I am at the end of crunch right now with deadline tomorrow.
I'll see to make more tests after that.
Cheers,
-Martin
Frank Lenhard wrote:
> MW> Spikey meshes happen with local subdivision applied and no render time
> MW> subdivision. These artifacts seem to be gone with raytracing primary rays.
>
> do these only happen in conjunction with mblur? or do they happen all
> the time with you? i never saw these here... just the blurry
> streaks...
---
Stefan Andersson
we never seen it before. And then it struck me, this was the first
time in a long while we rendered something that had an envelope on it.
Usually we only work with point caches.
I'll see if I can do some tests comparing the two. It might be a
envelope OP problem as well.
regards
stefan andersson
--
Stefan Andersson / vfx supervisor / Swiss International AB
S:t Eriksgatan 48 B / SE-11234 Stockholm / Phone: +46 8 662 24 60
Michal Doniec
Halfdan Ingvarsson
From: owne...@Softimage.COM [mailto:owne...@Softimage.COM] On Behalf Of Michal Doniec
Sent: 05-Sep-2008 9:34
To: X...@Softimage.COM
Subject: Re: Render Artifacts with XSI 7 / MR 3.6
Alan Jones
<hing...@softimage.com> wrote:
> Well, what can I say... It's fixed now.
You rock Halfy :) Thanks for the relentless pursuit :)
Stefan Andersson
(again, we haven't forgotten... as Raffaele said)
;)
regards
stefan
--
Stefan Andersson / vfx supervisor / Swiss International AB
S:t Eriksgatan 48 B / SE-11234 Stockholm / Phone: +46 8 662 24 60
---
Doug Nicola
~Doug