v-ray lights slow rendering 10x....

[Giovanni]

Hi all,

I have an interior scene, with 100+ max spot lights, with mapped shadows, 3 v-ray rectangular lights, and IRR+LC light map done (with all lights on) and saved.

Rendering time WITH ALL lights ON is 1 hour+ per frame.
Rendering time WITHOUT the 3 v-ray lights is 5 to 10 minutes per frame.

The slowness happens even for those frames where actually the 3 v-ray lights DO NOT really contribute to lighting (because it'ss a different room).

I tried to debug the scene for hours (MERGE, lights parameters tweaking, etc.), and still I cannot understand what is going on.

Finally, two weeks ago, I did actually manage to render the same scene at the "low" rendering times, even with the v-ray lights ON, so, I know the scene is renderable with decent rendering times.

Any idea? Is there something I am missing, besides "use v-ray lights only"? Does it ever happens to "you"?


Thank you

regards,

gio

[jujubee]

What are those Vray light settings? Either check through properties or the vray system rollout. If its 1500 subs then its way too much. Try lowering them to 50 each.

[DaForce]

Also depending on where they are located that can cause problems as well... for instance if they intersect geometry or a few other certain situations they can cause excessive light bounces which slows the render time considerable I believe.

Perhaps try moving them a little and see what happens

[Giovanni]

thank you guys.
I have subdivisions at 8 (!)...

It turned out that I had to recalculate IRR+LC.
With the new saved map, it's rendering fine.

It must be that tweaking the lights' intensity and other parameters while using a fixed, saved IRR+LC map, screws V-ray up.

I would have thought that once the maps are saved, changing some minor parameters would have been fine...that is, tweaking the amount of direct lighting, and such.

But eventually there must be some memory leak, or other problems, when V-ray uses a precalculated map and a lighting setup slightly different from the one which generated the map.

Oh, well, it's all experience.

Happy new year to this great forum!

Buon Anno nuovo!

regards

gio