View Full Version : area light + shadows + gi = no specularity on glass
markalanthomas 03-24-2010, 04:12 PM On this scene I have disabled shadows on my area light because, due to the camera angle, shadows hardly show up anyway:
http://homepage.mac.com/markalanthomas/.Public/eiglass/noshadows.jpg
But when I turn shadows back on to compare the difference, and enable GI to make them render faster, the result is no specularity on the glass:
http://homepage.mac.com/markalanthomas/.Public/eiglass/shadows+gi.jpg
If I disable GI (but keep the shadows enabled), specularity reappears on the glass:
http://homepage.mac.com/markalanthomas/.Public/eiglass/shadows.jpg
Most curious.
Not a problem at the moment, since the scene looks fine and renders fast with no shadows enabled, but I'd be bummed if I wanted quick soft shadows to show up and had to lose my glass specularity in order to get them.
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arketype
03-24-2010, 05:05 PM
Hi Mark-
Can you post your project somewhere so we can look at it?
Dave
markalanthomas
03-24-2010, 05:57 PM
Here's the collected project:
http://homepage.mac.com/markalanthomas/.Public/eiglass/eandtproject.zip
markalanthomas
03-24-2010, 05:58 PM
I just noticed that enabling GI also affects the refraction.
arketype
03-24-2010, 08:59 PM
Mark,
This looks like a GI related bug, to me.
I posted your project and a bug report over at EIAS3D
http://www.eias3d.com/forums/tracker/issues.php?issue=24
We'll see what the Igors say about it.
Thanks,
Dave
markalanthomas
03-24-2010, 10:10 PM
Sweet. Thanks!
arketype
03-25-2010, 10:03 AM
Mark,
For a workaround, you could use the layer shader to render only the Specular for the scene (with GI off) then composite this in Photoshop with a full GI/ RT soft shadow render.
Dave
markalanthomas
03-25-2010, 03:27 PM
Good point! If I do another angle, I'll probably have to do that. For now, though, I don't even really need the shadow since from this angle it's nearly invisible anyway.
Thanks for the help!
buggsy
03-26-2010, 08:18 AM
Nice looking glass Mark. I find myself looking at it a second, and third time. Can you share your glass material setup and lighting if you haven't already somewhere else.
Buggsy
markalanthomas
03-26-2010, 10:10 PM
Thanks!
I talked about it a bit in another thread a few weeks back, but it's pretty basic really. One main light, which is an area light, and a spotlight putting the highlight on the wall. Nothing fancy about the glass settings, but I do always make sure to use low reflectivity values for glass and liquid objects — sometimes even zero — with a Fresnel value to drive up reflectivity at the edges. The Fresnel value to me is important.
I posted the project above, so you're welcome to download it and poke around.
It might seem like I have the raytrace recursions really high, but it needs to be high considering that I have four overlapping transparent objects.
One thing EI could use is some transparency absorption controls. Volume transparency doesn't give the same effect, unfortunately.
But I love the look of EI's renders. I have this same scene in modo, but modo's renders, while very realistic, always seem to lack warmth and magic, if you get my meaning. Plus modo's anti-aliasing is just terrible. I'm constantly fighting with it and always end up with ugly artifacts in transparent objects. The EI render just looks so lush and warm and seems to have weight to it, and the anti-aliasing is nearly flawless. Very nice.
markalanthomas
03-26-2010, 10:12 PM
Oh, I should mention that I have two vertically-oriented luminous planes in the scene which serve just to add specular highlights to the glass — a white one on the left, and a green one on the right. Really adds some beauty, I think.
PaulS2
03-27-2010, 01:59 PM
Good looking project!
I wish everything had EI's render quality.....it's so forgiving when jobs need to be done quickly. I really find the interface and just general work-flow for GI and the newer features, feeling very awkward to use.
Give me EI's output quality and hi-res with Modo's IPR and speed (for some stuff) I'd be very happy. Modo's material system is such a let down...powerful but so kludgy and so busy.
Oh well, don't mean to turn this thread into modo bashing:-). Good work, Mark!
markalanthomas
03-28-2010, 05:47 AM
Anytime I need something done fast with killer quality it's EI I end up using. Every damn time. And usually I don't even need GI.
I'm so with you on modo's materials system. It actually hurts my brain sometimes just scrolling through the hierarchy trying to find what I'm looking for.
But those modo previews.… (Yeah, but that Trucoat™) That's its killer feature for sure. Every 3D app should have that.
PaulS2
03-28-2010, 09:16 PM
I agree every 3D app should have that....been checking out Octane. Looks like it might be worth investing some time into it.
http://www.refractivesoftware.com/index.html
markalanthomas
03-29-2010, 01:42 AM
Yes! I've been eyeballing Octane ever since I first saw the videos of its interactive previews. The DOF preview alone is mind-boggling.
arketype
03-30-2010, 05:26 PM
Hi Mark,
The Igors have confirmed the bug and it has been fixed (for the next official release).
They also said that it only happens when GI shadows are on and transparency is 0.00.
So a valid work around would be to use a non 0.0 value, like 0.005
Good luck. ;)
Dave
markalanthomas
03-30-2010, 06:10 PM
Fantastic news! Thanks so much for your help!
buggsy
04-01-2010, 01:16 AM
Just checked out your website! :bowdown:
Your one seriously talented artist. I love how you capture the lighting in so many of your paintings. I particularly like the portraits and the beach scenes. Have you ever had an exhibition? If not you should consider having one! :arteest:
Michael
markalanthomas
04-03-2010, 05:08 AM
Thanks, Michael — that's really cool of you to say.
I have had a few casual shows over the years, but I have this a tendency to avoid forced social situations, so I haven't been compelled to pursue that sort of thing even though I know it would probably benefit me. Plus I don't really feel like I'm breaking new ground with my work. But I do realize that an artist is usually the worst judge of his own work!
Ideas
04-03-2010, 02:45 PM
Yes! I've been eyeballing Octane ever since I first saw the videos of its interactive previews. The DOF preview alone is mind-boggling.
Probably somebody has posted this already: http://www.caustic.com/index.php
But the advantage is that it could work with Camera!
Real time feedback instead of those dozens or hundreds of test renders.
Michael.
futagoza
04-03-2010, 03:15 PM
I think this was already mentioned long time ago. However the disadvantage i see is that one would need to buy their Graphics Card too in order to use their technology. The better approach would be IMHO to use CUDA or OpenCL which would EIAS users cost nothing expect the regular software updates, assuming in the case of CUDA that EIAS users have an Nvidia Graphics Card.
Regards
Stefan
futagoza
04-03-2010, 03:28 PM
Ah, and one more thing... I believe GPU technology, wether from Caustics or the ones i mentioned would also need a good amount of memory on your graphics card, in order to render high res/high poly count images or animations. Maybe Paul can tell us a bit more about testing Octane with high-res work.
BTW. since you mentioned this, how would that work with EIAS?! I mean Animator and Camera are two applications. In order to have a nice realtime feedback, while applying shaders, setting lights etc., then a mini Camera app. had to be in Animator, or am i wrong?
Regards
Stefan
Ideas
04-03-2010, 07:46 PM
Ah, and one more thing... I believe GPU technology, wether from Caustics or the ones i mentioned would also need a good amount of memory on your graphics card, in order to render high res/high poly count images or animations. Maybe Paul can tell us a bit more about testing Octane with high-res work.
BTW. since you mentioned this, how would that work with EIAS?! I mean Animator and Camera are two applications. In order to have a nice realtime feedback, while applying shaders, setting lights etc., then a mini Camera app. had to be in Animator, or am i wrong?
Regards
Stefan
Good questions - which is why I've put it up on the EIAS3D forum.
Maybe the Igors could give some answers?
Michael.
futagoza
04-07-2010, 12:21 PM
Hi Michael,
now you have your answer. Not very convenient...;-) I assume after thinking about it for a while that it does not fit into the EIAS code base. I´m no programmer, but something tells me that in order to have new features like this or others like 64bit etc. for example, they would need something like a core rewrite of the whole system. EIAS even not has a standard OSX UI and i believe somehow in order that this should work you would need one, in a unified environment. Not to mention if old 3rd party plug-ins would work with that too.
Just my two cents.
Regards
Stefan
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