topic Cinerender Black Reflections in Visualization

Cinerender Black Reflections

Anonymous — Thu, 11 May 2023 09:38:25 GMT

Hi all,

I am having issues whilst using the cinerender engine when faced with multiple layers of glass. It seems that I have reached the 'maximum' number of reflections that can be calculated, and therefore within that area, the reflections/glass just appears as black once rendered.

I have tried to turn up the Ray Threshold, Ray Depth and Reflection Depth all to 50, however this has not made any difference to the final image.

Any ideas as to where to go from here would be amazing!

Thanks

Re: Cinerender Black Reflections

Erwin Edel — Thu, 11 Jan 2018 15:42:07 GMT

Treshold should be 0, not 50, for more reflections. Depth at 50 is a bit overkill, but that is the correct parameter to increase if you are missing layers of transparancy / reflection. I've generally not had to go above 12 here, so maybe dial it down to 20.

Treshold sets at what point cinerender will cut off rendering reflections, even at 1% this leaves scenes looking dull, in my opinion, so I just set it to 0 to show all reflections.

Also make sure that transparancy and refraction and reflection and such are ticked on in the general options (where you set everything to 50 before).

Re: Cinerender Black Reflections

Anonymous — Fri, 12 Jan 2018 11:09:54 GMT

Thanks for the advice Erwin. That worked a treat.

I got trapped into thinking the higher the number would mean more reflection bounces.

I also managed to get through to Graphisoft Support and they said the 'best' settings to try and stick to is as follows:
Ray Threshold: Between 1 - 2
Ray Depth: 9
Reflection Depth: 5

Re: Cinerender Black Reflections

Erwin Edel — Fri, 12 Jan 2018 13:05:37 GMT

Opinions differ, especially with interior renders, where you have a lot of glossy finishes, it looks heaps better with treshold at 0, in my opinion

Those depth parameters are quite low as well, if you have several layers of glass you will end up with missing surfaces at the back.

You need a setting of 3 for depth to see through one glass panel, so 5 would be only 2, if you have any tree objects (for example) with alpha channel leaves in the very background, you need 1 more level of depth, that is why I use an even number. 12 (what I ussually have), means I can see through 5 layers of glass and still see a tree through the last one.