The final rendering of the bubbles still presents a black problem.

[66175545]

Please tell me, the rendering depth is set as shown in the picture, but the final rendering bubble still appears black, is the transmission depth not enough?

[lee_griggs]

Have you enabled standard_surface.caustics? Also, try to ensure that there are no intersections and the normals are correct.

[66175545]

Enabled standard_surface.caustics but the blacks seem to disappear when using arnold CPU rendering mode, I wonder if this is related to the arnold GPU limitation (flaw), also it's hard to avoid bubble interspersions when using c4d particles (is this a reasonable request for the user?). Is the suggestion to look at optimising the arnold GPU engine to solve the problem occurring, thus bringing better ease of use and friendliness?

[lee_griggs]

It may be due to the particle shape. Try assigning the same shader to a sphere to see if it still renders black.

[66175545]

Ok, thank you very much for your careful pointers, after trying to use arnold CPU mode to render the output image as below, where it is the same render depth setting as arnold GPU, and there is no black colour when projecting the small bubbles in CPU mode, to answer your question:I am giving them (particles) the same material sphere.

[peterDTE7K]

with GPU you need to dramatically increase specular ray depth to fully get rid of black patches on transmissive objects

[66175545]

Thanks for your reply, I tried again to modify (crank up) the render depth, but the result still comes out with black artefacts on the projected material, as shown.

[peterDTE7K]

You need to increase specular ray depth not transmissive ray depth. Sorry I wasn't clear - 48 transmissive is way too much and the amount you need depends on scene, simple bubbles don't need such high amount.

Try this:

Increase specular ray depth to 20 and set transmission ray depth to 20. If it fixes your problem then decrease those values until you have result which you are still satisfied with.

 

[66175545]

Thank you very much for your careful guidance, I tried the GPU model under changing specular to set to 2 and 32 respectively and transmission to set to 48 and 32 respectively. is that they give me the same result in the output graph display.

[wernienst]

Maybe a glass material setting? Have you activated some of the surface effects like Coat (right half of my rendering)?

[66175545]

Thank you very much for your guidance, I packaged up my project (which uses c4d particles), if you would like to take the time to look at it.

[wernienst]

Unfortunately, I don't have an Arnold licence for Cinema4D, so I tried to recreate your scene in 3dsMax as close as possible using the geometry provided and Tyflow for the bubbles. I get this:

Here are the Render Settings:

I've also added a Denoiser Oidn Imager.

Below is my bubbles material.

[66175545]

Roger, thank you very much for your kind help, may I ask if you are using arnold[...] I am using DCC C4D + arnold CPU rendering mode does not show black shadows, but while testing arnold GPU I found this black shadow appearing problem, so I would like to optimise and demand help in arnold GPU mode.

[wernienst]

For my scene I used Arnold (7.3.2.1, MaxToA 5.7.2.1) as Renderer in GPU mode and Standard Surface materials only. Have you tried my provided bubble material? (Just import the bubblemat.ass file above. Look here how to do it:

https://help.autodesk.com/view/ARNOL/ENU/?guid=arnold_for_cinema_4d_ci_Utilities_ci_Material_Import_...)

[66175545]

Ok, thank you very much, I'm in the process of rendering a certain project, I'll render the files you've taken the time to help me with, thank you very much, and I'll report back to you with the results of my rendering after that (expected next Monday).

[66175545]

Hello big guy, after testing (importing the ass file material you provided into the previous project and rendering it with arnold GPU), the result is as shown.

[66175545]

Hello big guy, after testing (importing the ass file material you provided into the previous project and rendering it with arnold GPU), the result is as shown.

[wernienst]

Sorry for not being helpful! Maybe someone with access to C4DToA may jump in now.

[66175545]

Thank you very, very much for your patience and detailed help, our common goal is to help make the Arnold GPU renderer even better.