window caustics

[teabag]

Hello guys,
i was wondering whether there is any universal caustics setting for setting up nice window glass refraction caustics as can be seen at
http://www.chaosgroup.com/forum/phpB...hlight=zuliban

ive read the stuff in the help file but i am getting really ugly results...

basically i had multiplier at 17000, max photons at 600, light caustic subdivs at 2500 and search distance at 100...
window is quite large, approx. 2500 by 2500mm.

thanks for any help

Martin

[vlado]

Where in these images do you see caustics? I believe the glass had the "affect shadows" option ON, which will allow light through it without the need to use caustics.

Best regards,
Vlado

[joconnell]

Are you talking about the haziness that's at the windows? In that case it's a glow effect added in post - something like this: http://www.neilblevins.com/cg_educat...ular_bloom.htm

[teabag]

sorry i meant these images....ive mixed up the links...
http://www.chaosgroup.com/forum/phpB...=15058&start=0

ill post the sample soon...

[Da_elf]

i dont see any caustics in those either. unless im blind

[teabag]

well in that thread zuli is saying he is using caustics...anyway here is the sample..


I have this setting for caustics:
multiplier 15000
search dist 100mm
maxphotons 2000
in the light properties ive set the caustics subdivs to 2000

if i dont use caustics i dont get any light visible behind the part of the balcony window where the glass is...and ive got affect shadow and alpha checked...

where am i going wrong in both cases?

please help me guys

Thank you[/url]

[joconnell]

could you post a scene showing your lighting setup - you're not using vray planes on the windows or anything odd?

[teabag]

i have just one vray sphere as sun at 1.0 multiplier with 25 subdivs, and using LWF.

environment is at 2.2 as a global ambience level.

[teabag]

no hdri, no color correct

[RErender]

zuliban said that he used caustics but not photon type, meaning (I think) that he turned on "reflective caustics" in the GI settings.

[ene.xis]

hum...that makes sense...

[DaForce]

Yeah you need to have "refractive GI caustics" turned on in the GI rollout for "affect shadows" to actually work. (and then dont use Vray:Caustics)

If your going to try proper caustics use a direct light set to do the caustics only. That way you wont be wasting your light subdivs.

Although you wont need to.. and i doubt zuli used actual caustics for his renders.

Also zuli said "yes i used caustics but not photon ones also i activated ''affect shadows'' so light can pass"
Im certain he is talking about refractive GI caustics and then using affect shadows.. thats how he got the light thru the window.. not the caustics that your attempting.

[teabag]

ive done as you said guys, the zulis way without true caustics, just usin affect shadow and checking refractive caustics..
here is the test, lighting and modelling is not finished yet, the background image is there just for testing purposes, in the final it will be added in PS.



thanks a lot for your help and time guys

regards

Martin

[DaForce]

Looking good