render time with pre-calc GI

[maxedesa]

Maybe I'm doing something wrong with new settings, but I've been noticing that frames which render using pre-calculated GI are actually taking longer than when calculated per-frame. I'm certain that in the past, and intuitively, pre-calc GI frames were quite a bit faster. Has anyone else noticed this?

[maxedesa]

Now I'm reading that I shouldn't be using this antiquated method, and should switch to BF/LC....

[svetlozar.draganov]

Yes, BF+LC is the preferable GI setup with the latest version of V-Ray. It's the easier to set up and with the latest optimizations it is quite fast as well.

[maxedesa]

Thanks you. Either way, I'm still curious why the frames would take longer when they load an imap rather than creating their own. Any ideas?

[maxedesa]

Any help would be appreciated...

I get that BF+LC is the simpler, preferred method, but pre-calc is still a viable option, especially when time is an issue.

[BBB3]

I agree. It would be great to still have a quick and dirty option. BF+LC for animation is really only valid when using render farms. I did this (https://www.youtube.com/watch?v=pm0HjzPdj8E) using IM+LC, rendering one HD frame in between 2 and 5 mins on a single workstation, and it wouldn't be doable with BF+LC.

[maxedesa]

Don't you think its strange that frames loading IMaps take as long or longer than calculating themselves? This is definitely a change from previous versions. Any idea why?

[super gnu]

yeah ive also noticed that imap seems to be generally slower in all respects recently.. not done any actual scientific tests tho..

[maxedesa]

BBB3, by the way, really cool video

[Deflaminis]

Nice video Bertrand. Really cool stuff going on in there.

I don't think this is a new issue with the IR maps taking longer, I saw this with Vray 2.2 a while back.

[^Lele^]

I agree. It would be great to still have a quick and dirty option. BF+LC for animation is really only valid when using render farms. I did this (https://www.youtube.com/watch?v=pm0HjzPdj8E) using IM+LC, rendering one HD frame in between 2 and 5 mins on a single workstation, and it wouldn't be doable with BF+LC.

Quite the contrary, you'd just trade splotches and lack of detail for noise.

[maxedesa]

Nice video Bertrand. Really cool stuff going on in there.

I don't think this is a new issue with the IR maps taking longer, I saw this with Vray 2.2 a while back.

I meant that the frames which load the IR map take longer than if they generated their own. Maybe I wasn't explaining very well.

[BBB3]

Quite the contrary, you'd just trade splotches and lack of detail for noise.

But I'm not sure it would be more pleasant...

[^Lele^]

But I'm not sure it would be more pleasant...

Debatable.
I personally find the lack of per-pixel detail (and consequent lack of GI shadows) utterly disturbing, and 1990s looking to boot.
Yet, it doesn't need to float my boat: personal taste be personal, first and foremost.

[maxedesa]

vlado, Could you chime in on this?
Its really odd to me that the exact same frame, with the same settings (excluding GI) take the following times:

Frame calculating LC+IR each frame. 0:27:41
Frame only rendering, loading pre-calc'd GI. 0:56:08

These are on the same machine in our farm. Its part of an interior animation. When I started this post last month I was working on a similar project and had the same results. Its bizarre that a render needing only half the steps would take so much longer than one doing all the pre-calc. What changed? Any we we can have an option to switch back to the old way?

Caleb