neverending splotches threat

[deneb26]

hi guys.
i really tried everything out (different IrrMap-settings, with and w/o DE), i just don't get rid of this nasty splotches. of course i could use QMC, but it's deadly slow and renders darker than IrrMap.
have you guys a solution or the 'super-IrrMap-settings' i could apply?
btw. the scene is entirely lit by 1 vraysun.
thanks so much in advance.

regards
ale

splotches:


settings:

[vlado]

I think you would need a little more light cache samples; 400 is too low for this kind of scene.

Best regards,
Vlado

[deneb26]

hi vlado

you mean if i increase the LC samples the splotches in the background (doors) would vanish?
thanks for your fast response.

[brian451]

the size of the splotches is controlled by the irradiance map resolution (ie the max rate)
the variance in the color of the splotches (ie the quality of the samples) is controlled by hsph subdivs
the blending or smoothing of the splotches is controlled by interp samples.

you could easily remove the splotches by adjusting all 3 of these values

i would start hsph subdivs at 20 (since it has such a tremendous effect on render time)

i would stick with the presets

i would take inter samples up to 100 if necessary before going crazy with the other 2 settings

you should also use some vray light planes to act as fill lights in your windows and doors....it reduces the need for such high quality gi settings

[^Lele^]

I'd suggest you to try the method outlined in other posts on splotches, and to get rid of "check sample visibility".
If the geometry is very thin, give it some thickness.
You'll render WAY faster and a lot more cleanly.

[deneb26]

thanks guys, just checking your methods.
indeed i model the walls as thin planes.
so the way to go is to give them some thickness? but what's the porpose.
i have geometry which encloses the inner model, so that no light is entering where it should'nt.
still no luck so far.
if i don't succeed may i give the scene to you to look @ it lele?
i would appreciate that.
cU later

[^Lele^]

sure, send over the scene using the mail in my profile.

[deneb26]

file sent =)

thanks again

greez
ale

[nizzen]

Interesting thread;

'If the geometry is very thin, give it some thickness.'

Whats the 'math' here - can you please clarify?

Thx.

[Infrared digital]

I would suggest turning your Lightcache subdivisions up to 1500 and turn off sub-pixel mapping (in color mapping).

Also, check the suns shadow subdivisions - should be about 25 or 30.

[Neilg]

Also, check the suns shadow subdivisions - should be about 25 or 30.

...why?

Thats got nothing to do with those splotches, its for grain around your soft shadows.

[^Lele^]

Interesting thread;

'If the geometry is very thin, give it some thickness.'

Whats the 'math' here - can you please clarify?

Thx.

http://www.spot3d.com/vray/help/150R...p.htm#advanced

Check sample visibility - this is used during rendering. It will cause V-Ray to use only those samples from the irradiance map, which are directly visible from the interpolated point. This may be useful for preventing "light leaks" through thin walls with very different illumination on both sides. However it will also slow the rendering, since V-Ray will trace additional rays to determine sample visibility.

I didn't receive anything at all in mail, sure you got the address right?

[nizzen]

Thx for the quick answer. Then I misunderstood the sentences (maybe hoping for a 'wow make your renders twice as fast enlightning' - hehe).
I never use the 'check sample visibility' and make things 'thick' anyway.

[^Lele^]

http://www.chaosgroup.com/forum/phpB...ic.php?t=20221

Follow the links backward from there, you will find a way to cut down rendertimes and get rid of splotches on even surfaces.

[deneb26]

hi lele
yes i did, but to be sure i just mailed it again.
thanks
ale