dark juice

Use this forum for general user support and related questions.
User avatar
lacilaci
Donor
Donor
Posts: 1341
Joined: Fri May 04, 2018 5:16 am

dark juice

Post by lacilaci » Wed Aug 14, 2019 8:49 am

I had this problem before, where juice material got very darkened when looked at through glass. But before it was enough to setup volumes for glass and juice, now nothing helps and I'm not sure if I'm doing something wrong or not.

here's juice just as a volume and no glass
luxcore null juice base.jpg
here it is within glass object
luxcore null juice in glass base.jpg
also here it is not in glass but instead of null I use glass on volume itself
luxcore null juice glass material base.jpg
for comparison how I believe it should look here's cycles basic juice
cycles juice base.jpg
Anyone knows how to set this up properly so I don't get so dark juice? I tried shuffling around volume priorities and bunch of other stuff but it just doesn't help...

User avatar
FarbigeWelt
Donor
Donor
Posts: 772
Joined: Sun Jul 01, 2018 12:07 pm
Location: Switzerland
Contact:

Re: dark juice

Post by FarbigeWelt » Wed Aug 14, 2019 9:28 am

I the juice object overlapping the glass object at any point? Are normals okay (I guess so). Is internal and external volume correct?
Glass int. glass, ext. air
Juice int. juice ext. air
160.8 | 42.8 (10.7) Gfp / Windows 10 Pro, intel i7 4770K@3.5, 32 GB | AMD R9 290x+RX 5700 XT, 4/8 GB
17.3 | 19.0 ( 4.7) Gfp / macOS X 13.6, iMac 27'', 2010, intel i7 870@2.93, 24 GB | ATI Radeon HD 5750, 1 GB
#luxcorerender | Gfp = SFFT Gflops

User avatar
lacilaci
Donor
Donor
Posts: 1341
Joined: Fri May 04, 2018 5:16 am

Re: dark juice

Post by lacilaci » Wed Aug 14, 2019 9:45 am

FarbigeWelt wrote:
Wed Aug 14, 2019 9:28 am
I the juice object overlapping the glass object at any point? Are normals okay (I guess so). Is internal and external volume correct?
Glass int. glass, ext. air
Juice int. juice ext. air
juice object is inserted a little into glass yes, checked the normals the're ok...

however.. I have only set internal volumes for both objects as you can see on screenshots and I don't have a world volume... Do I need world volume and set up external volumes for objects aswell??

provisory
Posts: 163
Joined: Wed Aug 01, 2018 4:26 pm

Re: dark juice

Post by provisory » Wed Aug 14, 2019 9:57 am

Use glass material for juice instead of null, then tweak volume settings until it doesn't look fine.
After that it will look good in the glass object too.

User avatar
lacilaci
Donor
Donor
Posts: 1341
Joined: Fri May 04, 2018 5:16 am

Re: dark juice

Post by lacilaci » Wed Aug 14, 2019 10:08 am

So I made world volume (clear with lowest priority) and added it as external volume to all materials.. but it won't help

Also it doesn't matter if I make juice material null, glass or glass+architectural, it always turns way too dark.

It all looks ok without darkening unless I add scattering to juice volume, then everything becomes super dark.

provisory
Posts: 163
Joined: Wed Aug 01, 2018 4:26 pm

Re: dark juice

Post by provisory » Wed Aug 14, 2019 10:19 am

In your images it's not too dark in null material just in glass material.
My experience is that volumes much darker in glass material than in null.
So I suggest that use glass material for juice and set low parametets to the volume, then start to strengthen.

User avatar
lacilaci
Donor
Donor
Posts: 1341
Joined: Fri May 04, 2018 5:16 am

Re: dark juice

Post by lacilaci » Wed Aug 14, 2019 10:23 am

if I use normal glass I cannot make the juice look correct no matter what...

Does anyone have some material setup that looks somewhat close to cycles or this archglass juice? (but this one also turns dark once in glass)
juice_architectural_glass.jpg

provisory
Posts: 163
Joined: Wed Aug 01, 2018 4:26 pm

Re: dark juice

Post by provisory » Wed Aug 14, 2019 10:33 am

What happens if you switch to not arch glass and increase juice volume scattering?

(I'm away from my computer now.)

User avatar
lacilaci
Donor
Donor
Posts: 1341
Joined: Fri May 04, 2018 5:16 am

Re: dark juice

Post by lacilaci » Wed Aug 14, 2019 10:35 am

provisory wrote:
Wed Aug 14, 2019 10:33 am
What happens if you switch to not arch glass and increase juice volume scattering?

(I'm away from my computer now.)
it's just dark and weird colors...

User avatar
FarbigeWelt
Donor
Donor
Posts: 772
Joined: Sun Jul 01, 2018 12:07 pm
Location: Switzerland
Contact:

Re: dark juice

Post by FarbigeWelt » Wed Aug 14, 2019 10:35 am

lacilaci wrote:
Wed Aug 14, 2019 10:08 am
So I made world volume (clear with lowest priority) and added it as external volume to all materials.. but it won't help

Also it doesn't matter if I make juice material null, glass or glass+architectural, it always turns way too dark.

It all looks ok without darkening unless I add scattering to juice volume, then everything becomes super dark.
Correct setup of internal and external volumes is imminent according to my experience.
Camera volume should be set to air too. Automatically detection makes nonsense sometimes, with very strange results due to wrong refractive index ior or other settings.

Actually liquid in a glass is a three external volumes case. Where objects overlap the higher priority defines the border. The glass has two external volumes: air and juice. The juice has also two: glass and air. Intuitively external volume is omitted where objects overlap and only inner volumes matter, as noted the one with the higher priority, i.e. juice.

Absorption [cm] of juice volume is rather extreme.
Set it to at least the diameter of the glass.
160.8 | 42.8 (10.7) Gfp / Windows 10 Pro, intel i7 4770K@3.5, 32 GB | AMD R9 290x+RX 5700 XT, 4/8 GB
17.3 | 19.0 ( 4.7) Gfp / macOS X 13.6, iMac 27'', 2010, intel i7 870@2.93, 24 GB | ATI Radeon HD 5750, 1 GB
#luxcorerender | Gfp = SFFT Gflops

Post Reply