Light leaks and GI quality issues

[teabag]

Hi guys,

We are experiencing some difficulties trying to find a right GI solution for our new WIP project.
Basically its a big room in classical style, with a set of four windows on both sides of the main camera.
We are using SolidRocks plugin for the vray setup with really high settings but we are still experiencing issues.

The room is lit by vray sun and we are using vray lights in SIMPLE PORTAL MODE in each individual window.
It doesnt matter where i put the portals, whether inside (in front of windows) or outside (behind windows)...the problem persists.

I have been recently in close touch with Jerome Prevost, the maker of SolidRocks plugin and we have not found a way how to get rid of this, even with the best settings.

The question is...have we actually run into limitations of the Irradiance map here?
Will the scene have to be rendered by using Bruteforce?
Ive noticed that when using Bruteforce method, all the issues have gone...which implies the problem must be within irradiance map.
I ve tried to check the sample visibility in the IM, it makes things better but it does not solve them completely by far.
Strange thing is that if you have a look at the chandeliers, the GI there is perfect...so why not everywhere?

Our goal is to have the scene lit nicely like the Russian guys have their classical interiors lit...

Below, please find the render and the settins we have used.
Every suggestion, tip or help is greatly appreciated.
Thanks in advance!



and now the settings and scene screen grab





Best Regards and THANKS!!

[vlado]

The problem might be in the light cache, and not the irradiance map. You can try turning off the "Store direct light" option in the light cache and see if this helps.

Best regards,
Vlado

[teabag]

Hello Vlado,

nope, it does not help, the problem persists....may i send you the scene for inspection possibly?

Thanks

Martin

[vlado]

Yes, you can send it vlado@chaosgroup.com

Best regards,
Vlado

[3DMK]

The question is...have we actually run into limitations of the Irradiance map here?

Irradiance maps don't deal with tiny details very well [such as in your scene] You would have to use much higher settings than what you have to get a perfect gi. If thats the highest solid rocks setting then it needs to have even higher settings for scenes like this.
I would suggest using 'DETAIL ENHANCEMENT' option in the irradiance map settings. This will use brute force to clean up the tiny details to a radius you set [about 100-200 mm should work well] The detail enhancement was added exactly for these types of situations...so give it a go..it works great


Will the scene have to be rendered by using Bruteforce?
Ive noticed that when using Bruteforce method, all the issues have gone...which implies the problem must be within irradiance map.

If you have enough render time ALWAYS use Brute force. It's the slowest solution but always the best by far.

Strange thing is that if you have a look at the chandeliers, the GI there is perfect...so why not everywhere?

It's probably not that perfect it's just that the reflections & refractions are hiding it.



Every suggestion, tip or help is greatly appreciated.

Throw away any PRESET plugins & learn the theory of vray more as it's the only thing that will get you through situations like this. Presets don't help you progress your knowledge & skills

Also Like vlado said--- Turn off the 'STORE DIRECT LIGHT' option so that your lights cast direct light & shadows. Under your current settings they don't.

Hope this helps

[teabag]

3DMK:

if you looked at my settings well, i am using DE! with radius of 92 in a screen mode and 0.333 subdivs multiplier.

you asked if this is the highes setting in solidrocks...well it is not...solidrocks is fully scalable and you can apply much higher settings...however, this setting should be high enough

i think i have the knowledge of vray deep enough for what i do, i use solidrock plugin because its a quick way to nicely optimize the scene without having to use calculator and creating delays in the workflow....actually solidrocks was the program that helped me understand the vray settings far better than the vray manual on this forum and Vray guide by Francesco Legrenzi (although he did a perfect job writing the book)...maybe you should have a look at the plugin first before you write something like that, hmmm?...

i am after constructive help....not after patronizing comments saying thorw away plugins and learn vray...sorry to say this but i could not help it

thank you for your input though.

scene lighting is probably the place where i am making mistake but i dont know where cos my portals are setup just properly and since the room has big openings on both sides, there shoudl be enough light coming in.

M.

[Subburb]

Hi all !
Teabag, did the "store direct light" improved the result ?

[teabag]

nope unfortunatelly
i ve replied that to Vlado above ...

[thablanch]

What if you check <check sample visibility> in the Irradiance Map rollout. Looks like this kind of issue to me.

[m_hinks]

Hi,

On first glance, your settings are dare I say mental! Id have to agree with 3dmk. I think the plugin has made a big boo boo tho not you.

min samples of 256, and a global mult of 8 = crazyness. I bet that scene could render in under half the time, and without the issues you have.

The plugin is just generalising that you ask for a better quality image, so simply up the global mult, which is a very bad workflow in my experience. Getting used to the plugin doing the work will not help you in another studio without the plugin, or picking up an old job.

You should def take a look at this tutorial -
http://gnomonology.com/tutorial/62

Cleared a lot of things up for me!

Good luck.

[teabag]

hmm...makes me think really...if Solid Rocks was such a bad plugin, working completely wrong, why in heavens it would be used by so many amazing artists outthere? Solid Rocks is a good tool period. Using it almost 3 months now, it has cut down my rendertimes drastically.

[t3dm]

just an idea..

try these settings for the irradiance settings:L

min rate -5
max rate 0
hsph samples 80
interp samples 40

take of detail enhancement and instead us a subtle dirt material.. maybe watch the value of the white wood/paint material on the skirting doors etc...

[Neilg]

Your settings are pretty mental, i'd never consider using the multiplier like that and such low irsettings.
Are you able to upload a stripped down scene? (just walls, doors, windows & lights)
I could spend 15 mins on it and try a couple different things later.

[HAWF]

I agree with guys, your IR settings are low and DMC sampler very high, would be nice if you can upload the scene.

I think with only IR preset high + 3000 LC samples (without store direct light) will do the right job in much less render time.

[teabag]

will do guys..will do in the evening and post the link here

Subburb:
maybe if you would like to join the discussion and explain here how the SolidRocks works? When you have time of course!