Reflection/refraction/bump prob

[shoopa]

Hi guys,

I`m having some reflection/refraction/bump issue and don`t know whats the cause.
As You can see on the exterior scene I`m getting some strange artifacts/dots in some reflection areas /car tyre and corresponding beton floor next to it, entrance door area - look for the zooms/;
then the wall material on the inside of window is going `crazy` - white dots etc.the same material on a wall in the hall just behind the intrance door is normal. /the craziness seems to appear on a refraction pass/; got the same effect on a night render..


lastly - I`ve added a slight bump to the grass texture - it looks normal, but the closer to the camera/observator I`m getting some black dots; the bump thing appeared similar on another render I did - interior and a carpet material...so I think its not a reason of a settings thing.

All the reflective materials have something like 32 subdiv.
the grass/carpet don`t have reflection layer.

I don`t know what can be the cause..I`ve been looking on the forum for anything similar/solution, but couldn`t find one.

Thanks/dzieki/gracias por ajuda/vielen dank for Your help!
y saludas a todos!

[arturmf]

Re: Reflection/refraction/bump prob

Man, i thought it was subdivisions....but as you said...the values are already high

maybe it is a bug

[fpedrogo]

Re: Reflection/refraction/bump prob

I'm wondering if you don't have the "sub-pixel" and "clamp output" options enable? Enable these option. They are located on the "color mapping" tab.

[shoopa]

Re: Reflection/refraction/bump prob

Thanks for reply
here are my base settngs for this scene



You`re right Fernando, the subpix and clamp output were unchecked.
It`s because I watched some tutorial about postp/compositing vray passes, there was a suggestion to uncheck them...
When I `checked` them and rendered I got this:



the dots were gone /reflection - doors, car reflecting in beton, bump/
but the craziness in the window got some splotchy thing
so I was increasing some parameters and rerendering few times and with the same settings as above and raised

Image Sampler MinSub 1 MaxSub 30

Irradiance Map
Min Rate -3 Max Rate 0
Hsph Subd. 130 Samples 60

Light Cache
Subd. 1700

I got this:



It`s almost ok, I just wonder if there is some other way to achieve the same result,
without increasing all these settings /because they take a lot...of render time/,
thanks for any suggestions

[fpedrogo]

Re: Reflection/refraction/bump prob

The problem was a bad sampling on the high light of the reflection/refraction, you should enable "Clamp output" and "sub-pixel" option inside the color mapping rollout.

Your actual setting are very high. Make a test with these setting


Image sample 1 , 8 or 2, 6
IrrMap -4/-1
HSph Subdiv. 80 samples 20
LC - 1200

[shoopa]

Re: Reflection/refraction/bump prob

Hi Fernando,
thanks for the rep,
Ill try Your settings and post a render in coming days
/!`m quite busy these days/