iglightcache calculation taking ages to calculate...if i turn on dispalcement

[chow choppe]

hi everyone

 

i am working on an interior render.

I am doing test renders at very low settings and my lightcache is taking a lot of time to calculate and it almost hangs in the middle.

my lightcache settings are very low

200 subd's

0.02 sample size

no of passes 4

screen mode

 

my irradiance mode is set to hsph 20, inter samples 20 and m using custom -3,-3.

 

If i turn off the displacement in global switches then it calculates fine within 10 seconds . My all furniture is using displacement so i can't turn it off globally.

 

what is wrong with my settings?

can anyone suggest anything?

 

thanks

Edited October 5, 2009 by 3dsmaxed
spell check

[SandmanNinja]

As I understand it, that's the 'cost' of using displacement. It's modifying geometry each time you render, so it has to do a lot of math.

 

The Pro: It's easy on your viewport when modelling

The Con: It increases your render time

 

There may be some tricks that users with more experience in VRay know, but that's a general rule of thumb.

 

Everything has a cost.

[Koper]

turn off "generate GI" for all you're objects that has displacement on them.

[kippu]

but actually have a geomentry under it which has no displacement and generates GI ...

 

or you can switch the displacement off during calculation stage

[WAcky]

Yeah I think you check the "tight bounds" option and that will make the displacement calculate during render time and not during precalc