Author Topic: VCM not so efficient with blurry refractions? (fireflies bzzzzzz)  (Read 7604 times)

2013-11-19, 05:06:03

CHRiTTeR

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Hi,

I'm new here and verry impressed thus far!

I was verry curious to see how the newish VCM method would perform (this is the main reason i decided to try corona).
Most tests i've seen use perfect glossy reflections/refractions and i find glossy/blurry glass sexy, i thought id test for myself how vcm handles it.
I found out it seems to be quite less efficient with blurry glass...

...or is it a bug? I wonder, because the fireflies have strange positioning (surrounding the object like a glow?)


Anyway, from all the tests i've seen with VCM i thought this render should've been 'done' by now, but clearly its not... (still rendering though, havent cancelled it yet).
Maybe it's me doing it wrong? Mostly using default settings though...


i have a small request/suggestion regarding this too: something like vray's 'affect shadows' option for refractive materials would be verry usefull for fast transparent shadows!


« Last Edit: 2013-11-19, 05:09:38 by CHRiTTeR »

2013-11-19, 10:01:32
Reply #1

Ondra

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this is most definitely a bug, can you post the scene?
Rendering is magic.How to get minidumps for crashed/frozen 3ds Max | Sorry for short replies, brief responses = more time to develop Corona ;)

2013-11-19, 11:59:21
Reply #2

CHRiTTeR

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Sure, here it is.
I cleaned it up a little; removed hidden objects, layers and unused maps. I also converted the glass object to an editable mesh (it was an npower nurbs object).

The settings i changed (and that i remember) are:
Main corona settings:
- max ray depth to 50
- use bdir with vcm
- mat editor quality to 10
- change location of primary solver to d: (c: is my ssd so i dont like it being spammed with writes)
Depth of field/Motion blur settings
fstop to 2
sensor width to 36mm
VFB Settings:
Display AA to 2
[EXPERIMENTAL]Renderer: PT/VCM:
initial lookup radius to 3

Hope you can replicate it and find the little troublemaker!

2013-11-19, 14:08:43
Reply #3

iliyang

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this is most definitely a bug, can you post the scene?

Please don't make me look bad and fix this ASAP :D

2013-11-19, 14:25:11
Reply #4

Ondra

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Please don't make me look bad and fix this ASAP :D

Are you open to a little extortion? :D
Rendering is magic.How to get minidumps for crashed/frozen 3ds Max | Sorry for short replies, brief responses = more time to develop Corona ;)

2013-11-19, 17:31:34
Reply #5

CHRiTTeR

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Had some more time to play around and apperently, the dof is also acting rather strange...

Heres the exact same scene, but i replaced the glass material with a near white diffuse one.
Left: dof on
Right: dof off
This time rendered using bdpt

Maybe its related to the other problem?
« Last Edit: 2013-11-19, 17:51:55 by CHRiTTeR »

2013-11-19, 17:34:13
Reply #6

Ludvik Koutny

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2013-11-19, 17:50:34
Reply #7

CHRiTTeR

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What exactly is wrong with that picture?

With that last one?
Notice the hazy/foggy look around the dof... especially at the top of the object, where it is brightest.
Its almost like a glow or ghosting of the object going on.

I think some dof samples might be spread too much out or something?
« Last Edit: 2013-11-19, 17:56:33 by CHRiTTeR »

2013-11-19, 18:55:57
Reply #8

Ludvik Koutny

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What exactly is wrong with that picture?

With that last one?
Notice the hazy/foggy look around the dof... especially at the top of the object, where it is brightest.
Its almost like a glow or ghosting of the object going on.

I think some dof samples might be spread too much out or something?

Is that VCM or regular path tracing?

2013-11-19, 23:48:48
Reply #9

CHRiTTeR

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What exactly is wrong with that picture?

With that last one?
Notice the hazy/foggy look around the dof... especially at the top of the object, where it is brightest.
Its almost like a glow or ghosting of the object going on.

I think some dof samples might be spread too much out or something?

Is that VCM or regular path tracing?

Those last 2 (with the white diffuse shader) were done with bdpt, the vcm option was not selected.

2013-11-20, 08:45:12
Reply #10

Ludvik Koutny

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What exactly is wrong with that picture?

With that last one?
Notice the hazy/foggy look around the dof... especially at the top of the object, where it is brightest.
Its almost like a glow or ghosting of the object going on.

I think some dof samples might be spread too much out or something?

Is that VCM or regular path tracing?

Those last 2 (with the white diffuse shader) were done with bdpt, the vcm option was not selected.

Ah, i see... only progressive integrator is currently fully supported in Corona. If you do just tests of various integrators, then keep doing so, as it helps a lot. But if you want to produce some actual work, then progressive is way to go. BDPT and VCM are not production ready yet :)

2013-11-20, 13:03:56
Reply #11

Polymax

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Do not use DOF with VCM, it not working properly.
Corona - the best rendering solution!

2013-11-20, 13:09:47
Reply #12

chilombiano

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this is most definitely a bug, can you post the scene?

Please don't make me look bad and fix this ASAP :D

Bulgarian technology! :p

2014-02-17, 21:09:01
Reply #13

Ondra

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Fixed
Rendering is magic.How to get minidumps for crashed/frozen 3ds Max | Sorry for short replies, brief responses = more time to develop Corona ;)

2014-02-18, 05:21:18
Reply #14

CHRiTTeR

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Awesome! I guess i cant download the version with the fix (yet?)