And here is the renders with reflection on/off for the bottom water layer.


No reflection



with reflection

IOR value for refl and refr is 1.33, no roughness, blue tint for refraction color.

Lighting and HDR are the same in both, however I found that in Blender the hdr is rotated to back (may be while exporting/importing fbx applied world transformation to the whole scene). Rotating the hdr to 180 solved the highlight mismatch. For further comparison I turned off the real lights and rendered the scene.


The bottle is made of double sided mesh with very thin thickness.
bottle water is solid geometry and is scaled down to 0.96 in x and z and 0.99 in y. To solve the intersection problem.
Droplets are hemisphere without any holes (I will remove the droplets and make another render soon!, may be the droplet placement has some issues, both renders shows strange result).
ice is a cube
water body is a cube with displaced top.
outer is a tank geometry with thickness


RPR render Blender



High contrast turned on in color management, view transform = standard


No color management, view transform = standard

Here is the render settings
ray depth = 16
Diffuse = 2
Glossy =8
Refraction =8
Glossy refraction =8
Shadow =4
Ray epsilon=0.02

Max samples=356
min samples=128



Centileo

iteration =2
raybounce =14


with post effect


without post effect

RPR seems to produce more lights/exposure than Centileo with same HDR. There is no exposure/ camera values changed in both renders. RPR may be shooting more rays?


with ray bounce =25 and post effects on


with c4d filter exposure=0.5






is liquid= on for water inside bottle, droplets, ice, water body, centileo exposure = 1

May you drop a scene to me to info@centileo.com for experiments with icecubes? With HDR texture, maybe using dropbox or google drive or some other filesharer.
Probably we can start with Transmission and/or Absorption = white and then start changing to get where it become different.
Also there seems to be the difference with gamma on rendered image or HDR itself. Or with expsure that you multiply for CentiLeo to get less dark, but still there is a difference.

Thank you for scene! Will check it and get back to you. Currently I don't have installed Blender, but will analyze the situation with the icecubes.
I would like to share some specific thing that can be relevant to this scene as well. Have a look at Maxwell Render documentation last figure:
https://nextlimitsupport.atlassian.net/wiki/spaces/maxwell/pages/22684680/Nested+dielectrics I hope they don't mind )
So looking at the last figure you may see that a good way of modeling the overlapping refractive objects like bottle glass and water object is to use the concept of nested dielectrics. According to this concept the water object borders (see red line on the figure) overlap the glass object. Both are refractive and have different IORs. To resolve this physically some renderers use the priorities but CentiLeo uses "Is Liquid" setting in Transmission Tab. Is Liquid should be set On for liquids like water in this case in case of overlap and it will help to make correct refractions.
The other nice thing is the ability to set IOR smaller than 1. In this case you can use not the overlap but model the bottle-water objects as one object with the borders between glass and water mediums. And on the interface (the surface) between both mediums the IOR of material should be relative IOR equal to IOR(glass) / IOR(water). This can take some computations, but it will result in another way of correct modelling. However the "Is Liquid" concept is simpler Sure I will describe all of this in a documentation with examples

Yes, CentiLeo renders internal reflections within the glass very efficiently. Less noise than other renderers. Keep in mind CentiLeo has Direct Light Clamp parameter in render settings, it's global, not per-material. This paramter has influence on the brightness of the highlights also for internal reflections.

Video tips are more time consuming to produce than text + images. So the documentation itselft will come first and next the videos, I will invite more people for that of course.
As for now, I am doing some complex technology improvements but the end for them is approaching fortunatelly

@Kirgman Thanks,
The ice and water look nice now. I never tried increasing the clamp values before.
Changing the IOR of ice to 1.5 and absorption color and distance seems to solve the issue. I have tried these settings before but was stuck at distance value and also with the default clamp light settings there wasn't much clear refraction happening on the middle ice cubes.

In prorender, there was refraction color added to the ice and tried the same color in Centileo before, it is rendering in different way. It seems like both renders handle things differently. I used the same material settings from Centileo (your settings) to RPR and the render is extremely different.




The post effects influence the scene very much, I did a couple of test.



Centileo with post effect (default)


Centileo post effect turned off


Centileo with custom post effect (override)

Did some adjustments on the same renders using c4d filter.

Centileo post effects default + c4d filter adjustments


Centileo post effects off+ c4d filter adjustment


Thanks a lot looking into the scene and providing the solution. It may take a while I shift my workflow into this amazing render. Waiting for the next update, have you finished yet?

Quote
Kirgman wrote: Thanks for sharing the images! Btw, I like the look of the icecubes you did. However there is probably needed to improve the water droplets on the bottles, they are too spherical

this site called Noedle has great water dripping Alpha texture maps for free.
I wonder if using that in displacement would look good?

I was thinking maybe instead of a surface material the water drops could be cloned soft body spheres with random effector for size, that run down the surface of the bottle.
I did a test the other day with soft body balls and with only 14 segments and a Subdivision surface applied it ran smoothly. I just needed to keep the soft body tag attached to the sphere object. So with them cloned to the bottle surface as render instances (multi instance I believe doesn't allow for dynamics) it might render well.

Maybe subsurface scattering for the ice cubes if you wanted to make a frosted inside look to them.
I just watched a neat video showing how that can make glaciers look nicer.

Quote

ssjenforcer wrote: Quote Kirgman wrote: Thanks for sharing the images! Btw, I like the look of the icecubes you did. However there is probably needed to improve the water droplets on the bottles, they are too spherical this site called Noedle has great water dripping Alpha texture maps for free. I wonder if using that in displacement would look good? I was thinking maybe instead of a surface material the water drops could be cloned soft body spheres with random effector for size, that run down the surface of the bottle. I did a test the other day with soft body balls and with only 14 segments and a Subdivision surface applied it ran smoothly. I just needed to keep the soft body tag attached to the sphere object. So with them cloned to the bottle surface as render instances (multi instance I believe doesn't allow for dynamics) it might render well. Maybe subsurface scattering for the ice cubes if you wanted to make a frosted inside look to them. I just watched a neat video showing how that can make glaciers look nicer.

Thanks for the site info, I will check.
Displacement may work good for simple geometry, may be for the above bottle. I have done several test with other renders using displacement map for similar scenes, but couldn't get the desired look. Too much jagginess and weird refractions with displacement.
The droplet is actually cloned hemisphere. I used it for simplicity. I have other scenes with properly modeled water droplets cloned on the bottle surface. I followed a tutorial long ago and created some dripping effect with thinking particles. Unfortunately I don't have access to those scenes now (my hard disk has some issues).
Here is the link to the tutorial https://lesterbanks.com/2013/01/creating-animated-water-drops-on-an-apple-using-thinking-particles-i...

Frosted look for ice cube is also done with other render, I used bubbles, cylinders inside the ice and applied different ior, for ice used some bump map and roughness in the refraction.
I never used sss with highly refractive scenes, too much to calculate. But with Centileo I may try.
Thanks for the tips.