VRAY displacement mod problems

[Yordan Zarev]

so, i'm using 3d displacement with a composite map in the texture slot thats a combination of procedurals and i am getting really buggy results in some of the shadows, here's a picture of what it looks like and the settings of the displacement and the map itself

result with wierd shadows around the bricks :
http://i61.tinypic.com/2ymcbyx.jpg

map settings :
http://i58.tinypic.com/24c5wlv.jpg

i haven't used displacement much and i really don't know if the settings are optimal (i'm kinda of working on a budget when it comes to RAM) so any info about how i can optimise that modifier better and fix the wierd shadows would be well apreciated

[Morbid Angel]

There are a few things that can lead to this result. First in your key light set the shadow bias to a lower value.

Second try increase number of subdivs in displacement and reduce edge length, it can be that some displaced ares do not get high enough subdivs.

[Yordan Zarev]

thanks for the quick response, upping the subdivs gave little result but still noticable, what made it work like it's suppose to was lowering the edge lenght from 1cm to 0,2cm butt it kinda upped the RAM usage at 4,6gb while doing the LC and at 3,6gb while rendering, i'm worried that i still have some objects to put in the scene, would probably have to make everything into proxiesm. I'm a bit concerned about it cause I've got an 8GB rig, and that runs out quite easily
here's another question -
i subdivided the mesh that i'm displacing quite a lot, and it helped me with ram preservation at the early tests, will subdividing the mesh further would be of any use ? has anyone experimented with that ?

[Morbid Angel]

in modern day 8gb is nothing, often os takes 3-4. Users usually have at least 16 or more I never have less then 64.

[Vizioen]

A little offtopic but that procedural looks quite nice

[Yordan Zarev]

thanks, i really wanted a nice look on that brick&finish material ... well, anyway that wall would be seen in an angle in most of the shots i plan for the scene so a little rough shadows wont be noticed but i really wanted a closeup on those bricks, hopefully my silly laptop pulls it trough

[Yordan Zarev]

so, that's the best i could get out of the displacement withouth overloading my system
http://i57.tinypic.com/2hgfgp4.jpg

[tsvetan.geshev]

Hello Yordan,

I also think the result is very good
Can you highlight where exactly is the problem with the shadows, because I can't see the issue even in the image from your first post?

[Yordan Zarev]

ofcourse i will
http://i58.tinypic.com/2rhah7d.jpg here you go, hope it makes things more clear. I know i'm being picky with this but it really bothers me in the closeups and when it is textured it looks ever wierder

[Svetlozar Draganov]

Thank you very much for the clarification.
Would it be possible to send us that scene along displacement texture for investigation?
Let us also know which 3DSmax/V-Ray versions you are using.

[Yordan Zarev]

thank you for the time&effort, here's the scene
http://dox.bg/files/dw?a=6742956aeb
it was created in 3ds max 2014/vray 3.1, but later i switched to max2016/vray3.2 but the result is the same
i'd love to hear what kind of approach would you guys have on that problem, as i simply increased the subdivs and reduced the edge lenght in the displacementm od rollout but it was at a cost of almost eating all of my RAM, i hope there is a smartar approach thanks in advance

[Yordan Zarev]

I'm sorry, I completely forgot, you'd need to have bercon and multitexture maps

[Svetlozar Draganov]

Would it be possible to attach those plugins as well or to simplify the scene?

[Yordan Zarev]

Would it be possible to attach those plugins as well or to simplify the scene?

http://dox.bg/files/dw?a=2df611b24c here you go they are simple plugins, so all you need to do is copy the files from the corresponding max version to the /plugins folder

[Svetlozar Draganov]

Thank you very much for the plugins as well.
The only way to fix those shadows is to decrease the edge length parameter of the displacement modifier to something like 1 or lower, Max subdivisions parameter could be decreased to 8 it doesn't affect the quality much.

You could save some memory if you pre-calculate Irradiance Map and Light Cache with displacement off, then load them from file and turn on Displacement for the final render. The end result won't be absolutely the same but it will be very very close.

Other tips for optimizing scenes to use less RAM during the rendering could be found here:
http://docs.chaosgroup.com/display/V...whilerendering