So I tried to setup lights made of meshes and using front back opacity so that I could have a light source(s) hidden from reflections etc.
It works but! rendering takes much more time to clean the noise... Is this normal?
front/back opacity
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Please upload a testscene that allows developers to reproduce the problem, and attach some images.
Please upload a testscene that allows developers to reproduce the problem, and attach some images.
Re: front/back opacity
By the way, much much cooler than having invisible light source would be having light linking!
Re: front/back opacity
Yes because MIS is disabled if the light can not be directly seen (i.e. instead of having 2 ways to sample light sources, there is only one). However the noise should take longer to clear on glossy surfaces (where MIS can be useful), not on matte surfaces (where MIS is less important).