MR Exterior lighting: How to go from FG-only to GI/FG: a workflow question

[nisus]

Hi All,

 

I'm suffering large render times because I got a lot of 3d-green in my scene...

My intial setup is using FG/multibounce, looks ok, but takes too long to render.

 

My idea is to save on the bounces by using GI because it's quicker (and so that I can exclude the 3d-green from the GI-calculations)... However, I'm not familiar with GI/FG for exterior scenes...

 

Can anyone give me a some ideas on a good workflow?

- do I have to add a normal-inverted sphere to catch the photons or not? (If so how, because now I cannot store the photons...(got an error))

- how many bounces do you use as an average?

- any other things I should be aware of?

 

rgds,

 

nisus

[Justin Hunt]

Only the usual of having big numbers for the GI and small one for FG.

 

Have you tried the trick of generating the FG at a smaller resolution, hide your trees/ bushes and glass.

 

Freeze the FG, unhide everything and render at full res.

 

Also exclude the trees ect for GI

 

JHV

[nisus]

uhu, done all that... Think I got a solution... it does not really make sense, but it works ,-)

 

nisus

[Justin Hunt]

whats the solution?

 

JHV

[nisus]

Lots of bounces in GI 6-12, NO bouces in FG (for now, this is... i found no difference between 0,1 and 5 bounces yet - although not all tests are finished by now!)) GI-smoothing with large photons, detailed (dense)FG,...

Trees and green: no generation of GI

 

Basicly:

GI = fast for bounces --> use those

FG = slow for bounces --> don't use

GI = bad for detail --> don't use

FG = good for detail --> use

 

It's like the manual, to get the correct detail:

 

GI 1m (i would say 1-10m)

FG 10cm (10-100cm)

AO 1cm (1-10cm)

 

I found GI to be weak, so I multiply by 5

 

this is it basicly

 

rgds,

 

nisus

[Justin Hunt]

Thats the good thing with GI/FG. GI to do the hard work and FG to clean up

 

Good luck and keep us posted on the progress

 

JHV