Hi everybody,
I have a problem with multiple objects having a glass shader.
In the example below I made a scene with 3 glass plates placed one behind the other.
The first render is done with standard renderer, the second with ray tracer.
In both cases ray detail multiplier is set to 1.0
For the ray tracer I used max paths per sample of 100.
The results are not really satisfactory.
Any ideas how to improve it ?
thx
test031_standard.jpg test031_raytraced.jpg
Set Render/Advanced/Subdiv Settings/Ray detail multiplier to 1 and
Render/Advanced/Max Ray depth in PT to higher than 5, until the glass isn't black anymore. Maybe this doesn't work in the raytracer, but it should in the path tracer.
Thx Hannes.
I have to correct myself: the second is made using the path tracer. Max ray depth is already at 100.
Doesn't work :(
Is it "Max Ray Depth in PT" (on Advanced tab) that is 100, or *Max Paths Per Sample* (on Quality tab)?
- Oshyan
Quote from: Oshyan on January 26, 2020, 08:16:54 PMIs it "Max Ray Depth in PT" (on Advanced tab) that is 100, or *Max Paths Per Sample* (on Quality tab)?
- Oshyan
hmmm - obviously i got that mixed up, thanks for the advice!
Much better, but still not perfect.
Max Ray Depth in PT is 13, it seems to be the maximum possible.
test031_pt.jpg
The black glass is gone, but did you set Render/Advanced/Subdiv Settings/Ray detail multiplier to 1? Otherwise the geometry behind the glass will be low res.
Quote from: Hannes on January 27, 2020, 05:55:17 PMThe black glass is gone, but did you set Render/Advanced/Subdiv Settings/Ray detail multiplier to 1? Otherwise the geometry behind the glass will be low res.
Yes, ray detail multiplier is 1.
The left side of the foreground element is not covering the second element and directly showing the terrain through this one single element.
If you observe the refraction the terrain detail is lower and that's why I agree with Hannes's question regarding the ray detail multiplier.
If the ray detail multiplier is really set at 1 then this a bug.
Can you doublecheck or post the tgd otherwise?
Hi, Not trying too hijack this thread but I had a go at this kind of setup as well.
Comment away, especially if there is anything noteworthy about the setup.
I find the results rather...I don`t really know wht to think.
CHeers, Klaus
here is the tgd for my scene...
thx for the support
test031d.tgd
Confirmed. Gasbutan, your settings seem to be correct. I also tried Klaus' file, and even reduced the IOR to 1.1 for testing. With the path tracer the detail of the terrain behind the glass objects is completely lost.
And there are still black glass objects even with the maximum Max ray depth.
Thanks, Hannes. Perhaps Matt or Oshyan should have a look at this then.
CHeers, Klaus
Thank you Hannes and Klaus for your confirmation.
Obviously a bug ?
Do you have 360 optimal crop region set? I don't see it mentioned and I notice some background reflection which would be controlled here i think (in KlausK's version). Perhaps it also makes a difference at multiple depths of glass refraction.
Here are some more test renderings with different settings.
All path traced. Settings not mentioned have not changed.
CHeers, Klaus
Looks like a bug indeed.
Yup indeed, won't take long until Oshyan or Matt will join this discussion here.
This should also affect underwater surfaces I'd tend to say, but those work fine with RDM., thus perhaps it might be an over-agressive optimization of the path tracer.
Interesting.
Did you guys try turning on "Ray Trace Everything", out of curiosity?
Quote from: KyL on January 29, 2020, 04:13:33 PMInteresting.
Did you guys try turning on "Ray Trace Everything", out of curiosity?
Yes, I did. No difference.
Okay thanks!
Hi,
I just installed the latest Frontier4.4.48 and gave the 3 glassplates another try.
Here is the result. Weird. This can`t be right, not?
This is the identical file which gave the top left result in the previous composited picture.
I attached the scene file again if anybody wants to take a look, again.
CHeers, Klaus
Quote from: KlausK on February 04, 2020, 07:27:47 AMHi,
I just installed the latest Frontier4.4.48 and gave the 3 glassplates another try.
Here is the result. Weird. This can`t be right, not?
This is the identical file which gave the top left result in the previous composited picture.
I attached the scene file again if anybody wants to take a look, again.
CHeers, Klaus
Huh. Wonder if this explains why my ocean is currently looking very speckled with black dots. Just installed latest frontier before working on the water. Refraction on even the top level don't look right.
This doesn't look right, especially at MPD 0.6 and AA6, everything is fairly smooth minus caching, but that water is atrocious. Just basic water shader, decay distance at 75. Foam is white so it's only where it's at and shouldn't be effecting this.
@WAS, What does it look like in previous versions? Could it be the roughness?
@KlausK, I'll work with your file to fix whatever's causing this. Thanks.
Quote from: Matt on February 04, 2020, 07:47:24 PM@WAS, What does it look like in previous versions? Could it be the roughness?
That's a good point. I did up the roughness up to .05, though I swear I do this for ocean water all the time. Could be the sun angle on the reflections. I'm throwing it at my render node tonight which isn't upgraded so I'll know if there is any real difference.
I have had some of these issues as well, but could not reproduce it really.
This is fixed in v4.4.49 (coming soon).
Thank you, Matt !
Great Matt, you're on a roll :)
hi,
just installed the 4.4.49 update version today and rendered the scene with the three glassplates with it.
These are the results: SR = Standard Renderer / PT = Path Tracer
That looks a lot more like what I / we expected with this setup, I guess ;)
CHeers, Klaus
ps: while rendering with the path tracer about 90 minutes of the the total time needed - that is about half of the rendertime - Terragen could only use a few cores on my machine because there were only two or three buckets left to work on.