hdr skyprobe spots

[kimgar]

hi,

i'm trying to light my scene using one of debevec's skyprobes, they light up fine, but i get these strange light spots in my renders :



anybody know what this is?

[Joost Ink]

try brurring your hdri a bit, its suggested in this forum before.

[kimgar]

wow, now i'm getting dizzy, i've tried back and forth with the vRay hdr map and the default one - both gave me spots. tried blurring the default one, and the spots disappeared.
so i reloaded my scene and rendered with default hdr import but NO blurring - and the spots are still gone...wellwell, nevermind it works now - thanks for the tip!

[Joost Ink]

that's probably because the old one is still in your buffer.

[voltron7]

I've had the same/similar problem before and it seemed to go away depending on the rotation of the hdr...Does this make any sense?
Also, what software allows editing (blurring) of hdrs?

Thank you

[ene.xis]

the sea material looks great!

congrats!

[DaForce]

try saving out a JPG from hdrshop at the exposure that you want and use that to light your scene. Should render fast and look basically the same and also it wont have the spots.

[Morbid Angel]

the problem with skyprobes is that they are very high range. Unfortinantly I dont think its possible to not have splotches with these hdris.

[Dschaga]

Unfortinantly I dont think its possible to not have splotches with these hdris.

That's not correct, because it's a question of the renderer and how well the renderer is distributing the lightinformations into the scene. Vray seems to have problems with placing hdris into the BG override channel ..we will see how well vaporware1.5 will handle hdri's.

..to be serious: you don't need the hires hdrs for lighting, you need them only for the reflections and so you better go with a 128x64px blurred hdr for lighting, because smaller hdrs will speedup rendering too!

[instinct]

Erm...well....it IS a problem with ANY renderer out there right now. Every renderer takes random samples to generate GI. Si you might have samples next to each other that hit black and a full HDR max spot....if they are next to each other you will get those bright spots....There has been mentioned cases wich could be gotten around by offsetting the HDR...This is just a dirty workaround i´d guess. Turning the HDR means turning it´s BRIGHT SMALL spots (like the sun!) to a different place wich MIGHT get the bright spots out of your camera frustrum. If you do a 360° turntable anim you will never get rid of them. The ONLY way to get around that in current renderers is by using a blurred HDR. The side effect causing the spots to disappear is actually spreading out bright spots in the hdr over a bigger region of the image and at the same time making a more "gradient like" border for them. This WILL reduce sharpness in the GI (=blurred shadows). What definately helps as a workaround is VRay´s new domelight. Because the domelight knows BEFORE rendering where the hard regions are in the HDR it is able to do better adaptive sampling. Hence reducing noise and artefacts. The only other way is heading towards a "realistic" GI solution by kranking up the samples like crazy. The main problem is that Mother Nature´s Samples are unlimited...so this is gonna take a while to get good results :P

BTW...am a *bit* drunk...so excuse typos and stupidities...

Thorsten

[Dynedain]

Erm...well....it IS a problem with ANY renderer out there right now

Well, somehow Debevic has been able to produce amazing results, granted he sortof know this technology inside and out.

[kimgar]

thanks everyone for your info, the image ended up like this:



a little blurring of the hdr did the trick, nothing special about the water really, just some bump and reflections - but thanks anyway ene.xis . those skies really got overexposed, hope this was not the image i sent to my client

daforce, i haven't tried it, but i don't understand how an overexposed jpg would work as a hdr? wouldn't the sun just behave as a 8bit image clamped at 255, thus not giving very much light to the scene?

[jonnybefree]

hi kimgar,
splotches? looks like a nice coral reef
between, i would post the BG in post.
nice images

[kimgar]

thanks jonny! yep, i should have spent some more time on that background, not sure if i did in the end - hope so....

...but coral reefs? heh, a vivid imagination is important in this business

[DaForce]

Hmmm your right.. it doesnt look quite as good.. renders faster.. but aint much chop.
I swear that used to be a work around for something... maybe it was reflections.. or maybe i got it confused with that was mentioned above.. a small blurry HDRI....

bah, atleast you got it sorted out