Light Leak Problem

A little update:

Light leaks has been kinda solved, by cranking up the min/max rate of the irradiance map. Image becomes grainy i guess as a result, even at medium settings, and lights subdivisions set to 10, with global subdivision multiplier set to 2.



your suggestion will be highly appreciated.

Thanks.

yung pagkagrainy is i guess by the light subdivs. also, try mo din gawin 0.02 ang shadow bias. good luck bro.

Not entirely about your problem but allw me to comment on your workflow.

As I have written before - upping global subdivs before fixing subdivs locally (mats, shadows) is a lazy mans work.

Upping the global subdivisions will automatically expand your computations for all ram intensive operations, like aliasing and GI etc. proportionallyeven if you really don't need them. If you are able to fix your materials and shadows with enough subdivisions in relation to your angle view or camera positions BEFORE - there isn't a need to up the globals LATER.

If you find the need to change gloabl material samplings or lights, try to find a free script : Vray material Lister and the script fix to gloabally change light shadow samplings via the light lister.

Touch the globals only to nudge the quality up when you already have an acceptable one. Not when you are still looking for one.

my guess is this light is caused by that nearby ceiling light (vray light material, standard self illum?).

try excluding the GI effect of that mesh and render with the same low settings.

^^
thanks for the insights sir v...it's my first time to mess with them settings, since it's my first time to encounter such a problem.

Now i have this idea, what if i drop the settings down and just work on that min/max rate, i guess, i could get some header on my render time with that.

By the way, this is a non-commissioned work, so i have plenty of time to work on the scene.

mushroom wrote:my guess is this light is caused by that nearby ceiling light (vray light material, standard self illum?).

try excluding the GI effect of that mesh and render with the same low settings.

hmm...the nearby ceiling lamp is just a glass material set with low opacity and low blurry reflection sir...

anyway, i've learned a lot regarding settings due to this predicament.

I'll be updating this thread, so we can all learn together.

another possible cause is the way the ceiling is modelled. the leak could be caused by the outside light.

anyway im suggesting based on what ive experienced. hard to tell - share the file so we can check.

arkiedmund wrote:^^
thanks for the insights sir v...it's my first time to mess with them settings, since it's my first time to encounter such a problem.

Now i have this idea, what if i drop the settings down and just work on that min/max rate, i guess, i could get some header on my render time with that.

By the way, this is a non-commissioned work, so i have plenty of time to work on the scene.

Since this is your first time - then its a good chance to stay away from that kind of workflow. People will hate you if you find yourself needing to share a light or an element in your scene. make it a habit to make your glossiness ready for rendering by giving them ample subdivs. I use a minimum of 24 for glossies that go until .9, anything lower takes 32 or more. Remeber that if you have enough glossies already locally via mats, the aliasing algorhythm will ignore them and spent their energies elsewhere because they are smart when you are smart - they won't spend time where you don't need them.

Now to confuse you more, I find myself lately playing with my own settings, Adaptive DMC, min 1 max 100. Using the DMC settings, I start with .01 noise subdivs for previews (checking my obevrall lighting, mats etc) For finals I go for .005 to a max of .001.

I'll discuss them someother time, I've confused you more than enough for today!

^^
ditto sir vertex, i also use that same settings, except for the adaptive DMc min 1 max 100 setup...now, it's making me curious, will it make my scene render faster if i try that one?

that light leak lead me to messing with the settings per se....but it is a very good learning experience, as far as settings are concerned.

I don't usually crank things up when i do production work, until the final setup. And this became an exception, still i have a few more days to go, before i start working on a real project, so, there's no need to rush.

arkiedmund wrote:^^
ditto sir vertex, i also use that same settings, except for the adaptive DMc min 1 max 100 setup...now, it's making me curious, will it make my scene render faster if i try that one?

I cannot say a categorical answer but my renders now are more acceptable in terms or rendering time even if I have lots of glossies. What my technique does is max the min/max areas right away so that the only dial I need to pay attention to is the DMC settings.

Less is more.

Also, when you are looking for that good setting combo first time, use a global mat (white or gray) temporarily and fix the lighting or overall setting there, if it looks good on a plain diffuse color - it will look good when the diffuse maps are turned on. That's how I set up things. One at a time. When you have many things to control before you - the tendencies are confusion, sayang na oras and failure. That's the reason why there is a Global Material Setting in Vray. Use it to your advantage!

mushroom wrote:another possible cause is the way the ceiling is modelled. the leak could be caused by the outside light.

anyway im suggesting based on what ive experienced. hard to tell - share the file so we can check.

sure...i'd be glad to share the file...i'll upload it via sendspace and post the download link right here...

For those interested with the file:

http://www.sendspace.com/file/rbd9oc

this will be available for a week....i'll post an updated image in awhile.

EDIT:

Here's an updated image:



Pardon the noise, as i just rendered it in low settings...finally solved the light leak issues...

arkiedmund wrote:

ser ayw po maopen ung link na binigay nyo po pede po ba pa upload po ulit?lalo na ung material ng curtain tnx po er arkied,,,

max 2009 na yan sir...he he he...just click sa link, at andun yung instructions paano download.

ser arkiedmund block dito sa audi ung link nyo po newei tnx po ganda ksi ung curtain material mo GODBLESS po.

ed, u mentioned it was solved even with low settings. how?

mushroom wrote:ed, u mentioned it was solved even with low settings. how?

i set the min/max rate of my irradiance map to -6/-4

Finally was able to do a render last night...

you know ed, i'd suggest you refrain from costumizing the min/max rate and use the presets instead, sometimes, medium preset would be best and the only thing I'd advice you to dial up is the hemispherical subdivs when you find the GI lacking in detail (you can turn on the visual references to find where the samples accumulate)

the reason I say so - messing with lots of controls (specially if you do not know what you are doing) can pose more problems than solve them.

But hey, you said you fixed the problem already!

@vertex:

yes sir...i solved it...no problem sir..i will go back to my usual setup until another problem arise..i usually just use the presets when doing renders, it is only now that i was forced to try something else to solve my problem. Because, all the presets still yielded a negative result.

and of course, i got the idea for that through google...

Thanks for the advice sir, it's always a pleasure to hear from you.

For those interested with the curtain bitmap, you know how to reach me.

I took a look at your file.

the problem above the ceiling was caused by the large shadow bias of the sun, which means, the raytracer couldn't find the object when it starts thinking about "hey I'm going to compute all thy shadows now". What you were seeing in the ceiling was the sun affecting the ceiling object's illumination but forgetting all about the the shadows. The real fix to the problem was (1) you rescale your scene (2) or lower the shadow bias of the sun. I didn7t have time so I picked the latter.

You might be wondering why it was happening, the answer is your scene scale. You must make it a habit to always model in real world scales because most of the physical computations in vray will rely on this. One problem brought about by not minding this basic rule is the predicament you experienced while rendering this.

Just played around. Testing the sun's illumination ( I turned off you omnis and other lights inside the room)


Testing the sun + the vraylights in the window ( I turned off you omnis and other lights inside the interior)


I'll try to make a quick renderwrangler version later.

I totally forgot about the shadow bias, i usually lower it in most of my scenes...thanks a lot sir...i'll make a quick note of that, and will always check on those items to make sure things won't be glitched next time.

Can't wait to see how the master will tinker with my humble little work.

I'll be keeping tabs on this..

di naman po ako ang master, si ronel yun!

I'll send you the rendering and the scene once I find time to work on it.

^^
a million thanks...just take your time sir...btw, na post ko na yung finished version...but, still i will wait for your version.

The enigma wants to get his hands wet on that scene too...

yeah, tell the enigs not to take his shirt off and show the boobies when he work on that. I'll see the two of you this feb! Lets have a longer chat and beers then!