V-Ray Irradiance and Light Cache and image resolution issue

[syrilgombert]

Hi there.

 

I have an issue with high res rendering using irradiance and light cache where it's causing light leaks.

I've tried increasing the settings for Irr and LC with no luck.

The image is being rendered at 5559x3706

Settings I tried and changed -

 

Irr.

Preset: med and high

Min rate: -3 to -5

Max rate: 0 to -2

Subdivs: 50 / 80 / 100 / 120

Interp samples: 15 / 20 / 30 (Did not really up this much and will kick myself if this is what would solve the issue) This does reduce detail the higher it's set and is why I don't tend to like adjusting this.

 

LC

Subdivs: 1000 all the way up to 5000

Sample size: 0.02 and 0.01

 

I've tried a bunch of combinations of the above with no luck at solving the issue. My final setting were as follows -

Irr.

Preset: high

Min rate: -3

Max rate: 0

Subdivs: 80

Interp samples: 20

 

LC

Subdivs: 2500

Sample size: 0.02

 

I finally gave up in trying to solve this and switched to irr and brute force, but sitting with a 80+ hours render that's currently running and I'm not to keen at having it render that long.

Would really appreciate help if anyone knows how I can solve this issue without losing a lot of the detail I'd like to keep.

 

3DSMax and Vray 3.0

[Francisco Penaloza]

It should not be 80+hours, unless you are using a very under performance computer, that's way too much.

 

When you see those "blobs" of light, it is always interpolation problem or low GI settings. I think your combination never hit it right,

With a medium preset on IRR and increasing the interpolation that problem should be resolved. for instance, 70 samples and 60 interpolation. LC to 1600 or 2000 everything else default, should give you a clean image. Maybe reduce the sample size.

 

When you increase the interpolation on IRR I will recommend to activate detail enhancement. that should take care of those small corners without the need of going all brute force. that could be your final option.

 

Having said all these, for interiors with VRay 3.x rendering Brute force +LC should not be that slow. But of course this depend of your scene, but for a decent computer rendering a 4K or 5K about 3 or 4 hours should be OK.

[syrilgombert]

Thank you Francisco.

 

I've got a i7 4790k with 16gig ram, so the PC's not the issue. I did use brute force as the secondary with a few setting that were needed to remove noise from reflective surfaces, so that would account for the huge time.

 

You completely right on that my combinations never hit the right spot as the settings you're giving now is not one of the many I've tried.

Will go give this a try this evening and from what I can see those setting will give me a very quick render, will just need to see if my fine details survive.

 

Will give the Brute force + LC a try as well. Never tried brute force as primary before, so very curious to see how that works.

 

Will post an update as soon as I know the results. Can't post the image, but if any issues I'll post a cutout again.

 

Thanks again Francisco, really appreciate the help and insight you just gave me.

[Chris MacDonald]

I always use Brute force these days, it just makes everything so easy.

[Francisco Penaloza]

I always use Brute force these days, it just makes everything so easy.

 

indeed.

[syrilgombert]

So I've been sitting here testing out all those settings suggested and still IRR + LC is not working.

Switched over to your suggestion of brute force + LC and I'm thinking that I'm starting to agree with you guys that brute force is just the better option than the headache of trying to get the IRR + LC to work.

Will be setting up for the final render now, so will see what type of time I'll be getting.

 

Again thanks this is helping a lot and looks like I'll at least be getting a render out in a reasonable amount of time. YAY!!!