Vray gpu 5.1 Max Ray intensity

[luisgamino2]

Hi slavcho brusev, Konstantin and Peter Chauchev

I did some experiments yesterday, i complete understand that this button in optimizations is very important to check it since it avoids fireflies.

What i checked and surprised me is that if You increase it to 40 or 60 You get a real brigth image Even brigther than using 20 by default and if You decrease it like 10 You don't get fireflies but the image is a Lot more darker.

For example lights on floors and walls looks really amazing if You increase MRI to 40 or 50, and all the global ilumination looks a Lot better using 40 or Even 60.

It seems that if You select 20 at MRI, some bright source of lights hdr or artificial lights are going to see a Lot darker... You can't see the real light but if You increase it to 60 You get some real and nice reflections.the all image looks a Lot better with 40 or 60 values.

Can You explain it a little bit. I'm using vray gpu 5.1

Thanks in advance

[Muhammed_Hamed]

Hi Luis,

Max Ray Intensity is basically your GI clamp, this affects performance as well as quality. Getting brighter renders with higher values like 40 or 60 is expected to happen, although the differences should be minor in most cases and this might lead to slower renders
You better leave this value at its default in V-Ray 5 ,if you use progressive mode and in some edge cases it might help to change this to suppress some GI fireflies. But I personally don't recommend that, there are other ways to deal with this kind of fireflies

Role of thumb in V-Ray's workflow is to use default settings, they work very well for both quality and performance.

Best,
Muhammed

[luisgamino2]

Hi Muhhamed

Yeah!!! I think i found something really interesting here!!!

I did 5 test... First test MRI with 20 the default ( default settings), second test with MRI 10... It looks darker but without fireflies.

Third test... MRI at 40... looks quite interesting global ilumination and artificial lights looks a little bit brigther and Also better reflections on tables and chairs.

Four test MRI at 60... A bit brigther, it looks Nice too.

Five test MRI at 100... This is too much, lights looks really bright and Also You don't get any contrast. It looks like a washed render.

And the last one one render with out MRI. It looks horrible, real awful since i get tons of fireflies it doesnt look right.

I found too muhammed that if You increase MRI You get a slower render times since You already posted this topic.

If You increase your MRI You get slower times for render but lights and global ilumination looks a little bit better.

In My experiment Muhammed since i want to understand how this software works i found that the Best settings are between 20 and 60 for MRI.

With the pandemic i have a Lot of time to try a Lot of things.

Thanks for the advice, i was just playing yestarday with some settings... This optimizations are very important.

I'm going to show some images as an example of what i have found.

[Muhammed_Hamed]

Thanks for all information Luis,

I added a task for myself to look into this, hopefully soon. If this improves visual quality, I will talk to devs and see what is appropriate here

Best,
Muhammed

[luisgamino2]

Here is the examples Muhhamed

First is with 20 at MRI the default

[luisgamino2]

Here is the other example with 50 at MRI i found this is the Best option not too much dark and not too much bright.

A little bit brigther than normal or dafault behaviur but at the expense of a little bit slower than normal.

About the time of the render is not that much... Is 10% the render time. You increase your render times by 10%. ( Not too much but i really like how with 50 looks)

The light is 60 wats.

Best regards

[luisgamino2]

Here is kind of the same Muhhamed

But light is 40 wats in real life

I tried to simulate the same light in the render than in My room.

If You compare it... It looks more like the render with 50 MRI and is only 40 wats.

[Muhammed_Hamed]

Very interesting findings, I will test on my side and report back soon
We might consider changing the default value, if 50 or 60 don't affect performance as much

Best,
Muhammed

[luisgamino2]

In this experiments i found that between 20 and 50 You get a better lights and better global ilumination and better reflections is not that much how it changes, Just a little bit, but for interiors this works very well.

Sometimes i used to see that vray lights don't reflect the real light that is inside the volume like in the pictures. But with this change i get a little better renders with a slighty slower render times.

Best regards