Errors when displaying caustics

Corona Corona for Cinema 4D Help Required
1

BELOW WE SHOW THE VFB AND THE CAUSTICS SETTINGS. THE AIM IS TO RENDER A SURFACE LIKE A LAYER OF WATER; CAUSTICS ARE ENABLED FOR THE WATER MATERIAL.

RENDER 01-CAUSTIC ON-INVISIBLE CAUSTICS
RENDER 01-CAUSTIC ON-INVISIBLE CAUSTICS1920×1021 225 KB

RENDER 01-PASS INVISIBLE CAUSTICS
RENDER 01-PASS INVISIBLE CAUSTICS1920×1021 89.2 KB
CAUSTICS ACTIVATED BUT NOT VISIBLE. INCLUDE/EXCLUDE: ONLY OBJETCTS

RENDER 02-CAUSTICS ON-VISIBLE CAUSTICS
RENDER 02-CAUSTICS ON-VISIBLE CAUSTICS1920×1021 268 KB

RENDER 02-PASS VISIBLE CAUSTICS
RENDER 02-PASS VISIBLE CAUSTICS1920×1021 212 KB

CAUSTICS ACTIVATED AND VISIBLE. INCLUDE/EXCLUDE: DON´T APPLY OBJETCS

RENDER 03-CAUSTIC ON-VISIBLE CAUSTICS
RENDER 03-CAUSTIC ON-VISIBLE CAUSTICS1920×1021 326 KB

RENDER 03-PASS VISIBLE CAUSTICS
RENDER 03-PASS VISIBLE CAUSTICS1920×1021 238 KB

CAUSTICS ACTIVATED AND VISIBLE. INCLUDE/EXCLUDE DON´T: APPLY OBJETCS WATER BUT VISIBLE CAUSTIC

RENDER 04-CAUSTIC ON-INVISIBLE CAUSTICS
RENDER 04-CAUSTIC ON-INVISIBLE CAUSTICS1920×1021 296 KB

RENDER 04-PASS INVISIBLE CAUSTICS
RENDER 04-PASS INVISIBLE CAUSTICS1920×1021 89.9 KB

CAUSTICS ACTIVATED BUT NOT VISIBLE. INCLUDE/EXCLUDE: APPLY ONLY OBJETCS WATER BUT NOT VISIBLE CAUSTIC

Can anyone tell me where I’m going wrong?

Firstly, it seems that INCLUDE/EXCLUDE works the other way round.

Secondly, in earlier versions of Corona with caustics, when I used the ‘selected object only’ option, it worked correctly and only displayed the caustics on the selected elements.

I’ve also noticed that render times with caustics have increased compared to other versions. Back in 2023, I used to render scenes with caustics enabled only in swimming pools, and the render times were fine. I think it’s taking longer now because the software isn’t correctly interpreting where I want to apply the caustic visibility and is calculating the entire scene with caustics.

I’m working on macOS Tahoe

Cinema 4D 2024.2.0

Corona Render 15 Hotfix 1

Thank you for your services and best regards from Spain.

2

Hi, sorry, but I don’t fully understand this report. I think this is mostly because of the formatting of the post where it’s hard to tell which description applies to which image. If you could fix that, so that it would be easy to understand what exactly each image is showing, that would be great.

If I understand correctly, you are adding the water object to the caustics includes/excludes list. Please note that this list only lists the objects which are included or excluded from receiving caustics.

If you add the water surface as the only excluded object, it will still generate caustics. It won’t receive caustics from other objects.

If you add the water surface as the only included object, then only the water surface will receive caustics. All other scene objects will have receiving caustics disabled.

This is exactly what we are seeing in your screenshots and it’s how this feature has always worked.

Please note that including/excluding objects will NOT reduce render times as it only “hides” caustics that would otherwise display on those objects, but caustics still need to be calculated for the whole scene.

If you can describe what exactly you are trying to achieve, I should be able to help you.