 | | | Subject: flicker amd drop out | Subject: flicker amd drop out 2005-07-06 - By Bright, Jason
Back
No worries.
The problem with the regular rendering modes is that you're still
effectively point sampling your geometry. Doesn't matter how high you crank
up your res/sampling -- it *will* have artifacts if the geometric frequency
is higher than your sampling frequency. Sometimes you can hide it with
jitter or a filter, but thats just trading aliasing for noise.
The 'rapid' mode starts from the other end and dices up the geometry into
small triangles, shades them and then collapses them into pixels. So even
when an object gets small (subpixel), you're unlikely to completely miss it.
prman is popular for a reason ;)
Hopefully one day mental images will remove the last few limitations about
rapid, make it the default, and throw out the old scanline renderer. Unless
you need tracing effects that are incompatible with rapid it's already a
beneficial default to always have on.
j
-- --Original Message-- --
From: owner-xsi@(protected) [mailto:owner-xsi@(protected)] On Behalf Of
Lawrence Chandler
Sent: Wednesday, July 06, 2005 2:55 PM
To: XSI@(protected)
Subject: Re: flicker amd drop out
Jason!!!!!!! Works like a charm. Thanks so much!
LC
-- -- Original Message -- --
From: Bright, <mailto:Jason.Bright@(protected)> Jason
To: XSI@(protected) <mailto:XSI@(protected)>
Sent: Tuesday, July 05, 2005 5:54 PM
Subject: RE: flicker amd drop out
A suggestion when you're dealing with thin geometric features that pop and
alias --- force on rapid scanline rendering (doesn't matter if you are using
motion blur or not). "ray3 -scanline rapid -shutter 0"
It uses a totally different tesellator and behaves MUCH better with small
features. More in the style of prman. Has saved my butt a number of times.
A lot of the time it's worth keeping this on as a default unless bad things
start to happen (it can still occasionally freak out on time or memory if
you have the right scene).
(If you were silly enough to pay to see Catwoman [my apologies] - there is a
shot that pushes through a building that had mirror windows with all these
really tiny modelled features around the glass panes. You'd think it was
simple, but that would not render at (3,3) without bad aliasing and hours a
frame. Turn on rapid and it came out perfect in a few minutes).
This only helps if your features are real geometry --- if they're coming
from textures then thats a whole other issue.
j
-- --Original Message-- --
From: owner-xsi@(protected) [mailto:owner-xsi@(protected)] On Behalf Of
kim aldis
Sent: Wednesday, July 06, 2005 7:44 AM
To: XSI@(protected)
Subject: RE: flicker amd drop out
I'm working on architectural shots right now, probably the worst anyone's
likely to get for aliasing. I'll keep you posted and if you want to nudge me
in a couple of weeks then that's fine, but for this kind of work I'm pretty
sure:-
min/max: 1,2 or 2,2. at 1,2 set threshold to around 0.1, less for fine but
contrasty detail is probably not going to get you much and at 2,2 the
threshold is irelevant. And Chris is right, turninng on dithering will amke
a big difference.
__ __
From: owner-xs[ i@(protected) [mailto:owner-xsi@(protected)] On Behalf
Of Chris Marshall
Sent: 05 July 2005 16:30
To: XSI@(protected)
Subject: Re: flicker amd drop out
Lawrence Chandler wrote:
II had my aliasing settings at 0 and 2 with the default threshold and .the
Mitchell filter. I did a quick test of Chris Marshall's suggested settings
(thanks Chris) and there was a definite improvement but still noticible
tearing with that chaser light effect on many edges. Do I try a higher
threshold or min max setting?
Thanx in advance,
LC
You need to play with this, but a lower threshold, maybe .025, and maybe a
min max of +1,+3.
Try changing the min max first.
Like Kim said, architecture is always a pain!
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<DIV><SPAN class=140034405-06072005><FONT face=Arial color=#0000ff size=2>No
worries.</FONT></SPAN></DIV>
<DIV><SPAN class=140034405-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=140034405-06072005><FONT face=Arial color=#0000ff size=2>The
problem with the regular rendering modes is that you're still effectively point
sampling your geometry. Doesn't matter how high you crank up your
res/sampling -- it *will* have artifacts if the geometric frequency is
higher than your sampling frequency. Sometimes you can hide it with jitter or a
filter, but thats just trading aliasing for noise. </FONT></SPAN></DIV>
<DIV><SPAN class=140034405-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN><SPAN class=140034405-06072005><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=140034405-06072005><FONT face=Arial color=#0000ff size=2>The
'rapid' mode starts from the other end and dices up the geometry into small
triangles, shades them and then collapses them into pixels. So even when
an object gets small (subpixel), you're unlikely to completely miss it. prman
is
popular for a reason ;)</FONT></SPAN></DIV>
<DIV><SPAN class=140034405-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=140034405-06072005><FONT face=Arial color=#0000ff
size=2>Hopefully one day mental images will remove the last few limitations
about rapid, make it the default, and throw out the old scanline renderer.
Unless you need tracing effects that are incompatible with rapid it's already
a beneficial default to always have on.</FONT></SPAN></DIV>
<DIV><SPAN class=140034405-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=140034405-06072005><FONT face=Arial color=#0000ff
size=2>j</FONT></SPAN></DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT
face=Tahoma size=2>-- --Original Message-- --<BR><B>From:</B>
owner-xsi@(protected) [mailto:owner-xsi@(protected)] <B>On Behalf Of
</B>Lawrence Chandler<BR><B>Sent:</B> Wednesday, July 06, 2005 2:55
PM<BR><B>To:</B> XSI@(protected)<BR><B>Subject:</B> Re: flicker amd drop
out<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>Jason!!!!!!! Works like a charm. Thanks so
much!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>LC</FONT></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT:
#000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">-- -- Original Message -- -- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:<
/B>
<A title=Jason.Bright@(protected) href="mailto:Jason.Bright@(protected)">Bright
,
Jason</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=XSI@(protected)
href="mailto:XSI@(protected)">XSI@(protected)</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Tuesday, July 05, 2005 5:54
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: flicker amd drop out</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff size=2>A
suggestion when you're dealing with thin geometric features that pop and
alias --- force on rapid scanline rendering (doesn't matter if you are
using
motion blur or not). "ray3 -scanline rapid -shutter
0"</FONT></SPAN></DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff size=2
>It
uses a totally different tesellator and behaves MUCH better with small
features. More in the style of prman. Has saved my butt a number of
times. A lot of the time it's worth keeping this on as a default
unless bad things start to happen (it can still occasionally freak out on
time or memory if you have the right scene).</FONT></SPAN></DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff
size=2>(If you were silly enough to pay to see Catwoman [my apologies] -
there is a shot that pushes through a building that had mirror windows
with all these really tiny modelled features around the glass panes.
You'd think it was simple, but that would not render at (3,3) without bad
aliasing and hours a frame. Turn on rapid and it came out perfect in a few
minutes).</FONT></SPAN></DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff
size=2>This only helps if your features are real geometry --- if they're
coming from textures then thats a whole other issue.</FONT></SPAN></DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff
size=2>j</FONT></SPAN></DIV>
<DIV><SPAN class=546573600-06072005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT
face=Tahoma size=2>-- --Original Message-- --<BR><B>From:</B>
owner-xsi@(protected) [mailto:owner-xsi@(protected)] <B>On Behalf Of
</B>kim aldis<BR><B>Sent:</B> Wednesday, July 06, 2005 7:44
AM<BR><B>To:</B> XSI@(protected)<BR><B>Subject:</B> RE: flicker amd
drop
out<BR><BR></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=578184121-05072005>I'm working on architectural shots right now,
probably the worst anyone's likely to get for aliasing. I'll keep you
posted and if you want to nudge me in a couple of weeks then that's fine,
but for this kind of work I'm pretty sure:-</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=578184121-05072005></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT face=Arial color=#0000ff size=2><SPAN
class=578184121-05072005>min/max: 1,2 or 2,2. at 1,2 set threshold to
around 0.1, less for fine but contrasty detail is probably not going to
get you much and at 2,2 the threshold is irelevant. And Chris is right,
turninng on dithering will amke a big difference. </SPAN></FONT></DIV><BR>
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style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #0000ff 2px
solid; MARGIN-RIGHT: 0px">
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<FONT face=Tahoma><FONT size=2><B>From:</B> owner-xs<SPAN
class=578184121-05072005><FONT face=Arial
color=#0000ff>[ </FONT></SPAN>i@(protected)
[mailto:owner-xsi@(protected)] <B>On Behalf Of </B>Chris
Marshall<BR><B>Sent:</B> 05 July 2005 16:30<BR><B>To:</B>
XSI@(protected)<BR><B>Subject:</B> Re: flicker amd drop
out<BR></FONT></FONT><BR></DIV>
<DIV></DIV>Lawrence Chandler wrote:
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type="cite">
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<DIV><FONT face=Arial size=2>II had my aliasing settings at 0 and 2
with the default threshold and .the Mitchell filter. I did a
quick test of Chris Marshall's suggested settings (thanks Chris) and
there was a definite improvement but still noticible tearing with
that
chaser light effect on many edges. Do I try a higher threshold or min
max setting?</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>Thanx in advance,</FONT></DIV>
<DIV><FONT face=Arial size=2>LC</FONT></DIV>
<DIV> </DIV></BLOCKQUOTE>You need to play with this, but a lower
threshold, maybe .025, and maybe a min max of +1,+3.<BR>Try changing
the
min max first.<BR>Like Kim said, architecture is always a
pain!<BR><BR>--- Unsubscribe? Mail Majordomo@(protected) with the
following text in body: unsubscribe xsi
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