Hello,
Sometimes it happens that even when using BF the scene goes through 1 prepass which idon’t really mind since its couple of seconds. But now it started running through 5 prepasses which is pretty heavy and i don’t see the reason for this.
Most of the times i am on DR, where it remains in 1 prepass but when i disable DR then it goes to 5 prepasse. I am using local host in all cases.
Vray 3.4
Thanks much for direction,
Stefan
You probably have interpolation enabled somewhere on a material, or sss material?
HM no sss for sure, and i am not using interpolation, but could happen that something like this was in imported model. Well that will be fun to look for.
Thanks will check.
Use VMC script
yes i have i bought even but it didnt unlock this option 
am looking manually
yes, found one interpolation but didn’t help.
In any case why should this be a problem ? i even tried BF+BF still the same issue.
Because things like interpolation have their own prepass
i see, this look like IM tho exactly
I wrote simple script for you just use this code in max script listener (F11) and it will disable all interpolation in your vraymtls
(mrmvmtl=getClassInstances vraymtl processChildren:true; (for i in mrmvmtl do (i.reflection_useInterpolation = false; i.refraction_useInterpolation= false)))
waw! thank you very much, tried it right away and the prepass is still there but now goes much faster. and in other scene it didn’t help
thank you very much 
didn’t expect that
Hello,
If you look in the V-Ray log (or in the file - vraylog.txt file in %temp%) - there should be lines about every material that has some interpolation enabled.
Best regards,
Yavor
Hi,
yes there is no more interpolation happening. but the passes didn’t go away.
It could be a fast sss material set to prepass mode instead of raytraced.
i tried to delete everything that could have sss. there was one object and i uplied to it just vrayMat, but still there. and even if so. there is no way around it ? i mean even if i had sss, it will be running the passes in any case ?
No, only sss set to prepass mode does it. vray is fast enough now that I use raytraced for all my sss & that doesnt do prepasses.
It’s still doing prepasses in brute force without interpolation or SSS?
use this using max script listener (F11) and it will change all fastSSS2 material to raytraced multiple scattering mode.
(mrmvmtl=getClassInstances VRayFastSSS2 processChildren:true; (for i in mrmvmtl do (i.multiple_scattering = 2 )))
yes. i mean there is everything as normal, but even on BF+BF it goes tru 5 passes
It’s either a sss2 material, or interpolated glossy reflections/refractions in some VRayMtl material. Although, in V-Ray 3.4 and 3.5 we just ignore those.
Best regards,
Vlado
yes i will take a look at it more carefully, it might be from some imported library even tho i tried to delete everything.
Will report when find it. Thank you