[SOLVED] Differences in reflection/refraction between H19.5 and H20

Forums Solaris and Karma [SOLVED] Differences in reflection/refraction between H19.5 and H20

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Siavash Tehrani: Member; 710 posts; Joined: July 2005; Offline

Dec. 2, 2023 11:51 a.m.

Hi all,
I was updating a scene from H19.5 to H20 and noticed some significant differences in how Karma is treating reflections/refraction. Has anyone else encountered this?

Edited by Siavash Tehrani - Dec. 24, 2023 09:35:56

Attachments:
beauty.gif (595.2 KB)
gcr.gif (1.2 MB)
gt.gif (364.6 KB)
dish_reflect_refract.usd (36.6 KB)


Siavash Tehrani: Member; 710 posts; Joined: July 2005; Offline

Dec. 22, 2023 5:54 p.m.

Bumping this with another example. Subjectively I feel like the H20 render is a downgrade, but I'm more concerned with physical accuracy. Is there some kind of optimization going on in H20 that's causing the different look?

19.5.733 vs 20.0.547
Karma XPU (but the results are the same with CPU)
Reflect/refract limits have been bumped to 50.
Scene files are attached if anyone wants to poke around.

Thanks.

Attachments:
reflectrefract_snifter.zip (10.3 MB)
brandysnifter_compare.gif (886.2 KB)


jsmack: Member; 7771 posts; Joined: Sept. 2011; Offline

Dec. 22, 2023 9:08 p.m.

Are the results the same when unclamped (color limit set arbitrarily high)?


Siavash Tehrani: Member; 710 posts; Joined: July 2005; Offline

Dec. 22, 2023 10:04 p.m.

Thanks for the suggestion jsmack. There is no visual difference when unclamping the color limit in this scene.


brians: Staff; 470 posts; Joined: May 2019; Offline

Dec. 23, 2023 3:18 p.m.

Perhaps the “Enable Internal Reflection” geometry setting?

Edited by brians - Dec. 23, 2023 15:19:01


tamte: Member; 8555 posts; Joined: July 2007; Offline

Dec. 23, 2023 3:33 p.m.

brians
Perhaps the “Enable Internal Reflection” geometry setting?

on my end I don't see it actually making any difference
EDIT: actually it does with increased limits

but it brings up an interesting point:
the rendergeometrysettings1 node in the original file doesn't have that property exposed
only a new instance of that node created in H20 will have it
and I don't see any of those properties in From USD section of Edit Parameter Interface, so it's not easy to know a new property exists

Maybe it'd be better to have an HDA wrapper around that node so that it reflects the definition of the current H version rather than being just a node with spare parameters that have to be managed separately

Edited by tamte - Dec. 23, 2023 15:52:10

Tomas Slancik
FX Supervisor
Method Studios, NY


jsmack: Member; 7771 posts; Joined: Sept. 2011; Offline

Dec. 23, 2023 6:35 p.m.

brians
Perhaps the “Enable Internal Reflection” geometry setting?

Shouldn't that be on by default. I can't imagine a situation that optimization would be worth the quality loss


Siavash Tehrani: Member; 710 posts; Joined: July 2005; Offline

Dec. 24, 2023 2:44 a.m.

Thanks everyone, "Enable Internal Reflection" did the trick! I was not aware of that parameter in H20.
I'd agree that it should be enabled by default. Too easy to miss, and the differences in the look are massive.

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