what to do with the secondary bounce during IrrMap precalc?

[leotchest]

I have precalcd the LC using Flythrough - two thumbs up.
I have precalcd the IrrMap using every nth frame + using the pre-saved Vrlmap for the secondary bounce - another two thumbs up.
When I go to render, the frame times are insanely high (like 2 hours instead of 40 minutes). Two thumbs down

I noticed that doing the precalc on the IrrMap went really fast when using the saved Vrlmap for secondary bounce - is this somehow causing my final renders to slow down ?

Essentially, my real question is this - I have got my saved LC in my pocket and next I want to precalc the IrrMap. What should I do with the secondary bounce when I am precalcing the IrrMap ? What I have outlined above is resulting in very slow render times ? Shoudl I just turn off secondary bounce ? (I tried that and it was taking ages to do the precalcs - I guess that could be the lesser of two evils)

Ive spent the last 3 days doing various tests to get rid of all the flickering, so now I am out of time to do more tests and hence this post

[percydaman]

if you saved your light cache into your irrad map, then you would turn off your secondary bounces, as your cached irrad map, now included both bounce information.

[leotchest]

forgot to mention the light cache is purposefully not saved in the irr map. I wanted to keep them seperate.
So, when you are not combining the LC into the IM (i.e. you have checked the box to include Gossies in the LC), I am wondering what do people recommend for the secondary bounce when precalculating the IrrMap ?

[Clifton Santiago]

What is the purpose of deliberately saving your LC and IR map separately?

[percydaman]

if you want your lightcache to accelerate your glossies, you have to have your lightcache separate.

[Clifton Santiago]

Yes of course, I use it for that all the time. But there is no need to render them in separate passes for this purpose. You can render the IR map every nth frame, and have it autosave as .vrmap, and the LC flythrough will automatically render every frame of the animation and autosave as .vrlmap, then on your render pass you load them separately.

I was wondering if there was some special reason you would render your IR map, wait for it to finish and save, then render your LC map, wait for it to finish and save. Not to mention that you would have to set secondary bounces to none while doing the IR map, and the primary bounces to none for LC map. It seems like an overly complex workflow unless there is a good reason.

[trixian]

It's usually the other way around. First you bake your LC in fly-through mode, then bake your Imap with the LC loaded. This is if you want your LC as part of your Imap though.
But as Percy pointed out, you then have the option to turn off secondary all together if you wish, unless you need it for the fast glossies.

[Clifton Santiago]

Yes, exactly. I render them together and load them separately when using LC for glossies. And when not using glossies, I set secondary bounces to none on the render pass. Vray 101.

What I was wondering about is the benefit of rendering them as completely separate entities. Is there one? And if so, what is it?

[percydaman]

ya your right, ive never done them completely separate, regardless of using lightcache for glossies.

[RErender]

I'm with Percy, just bake the LC into the saved IRmap from the beginning and if you need it save the LC for the glossies.

[leotchest]

To clarify - I dont have any specific reason for doing them seperate - i was just experimenting. What really concerns me is why using a precalculated IrrMap & a precalculated LC is causing the render times to become a lot higher than if I were to render without using any saved maps. In theory, the render should be quicker using the precalcd vrmap & vrlmap - but its rendering a lot slower. On this particular job I saved a LC first (with include glossies turned off) - perhaps that is causing the slowdown.
From now on I will save the Flythrough LC together with the IrrMap (I didnt realise you could combine a Flyhrough pass with an every nth frame pass)

[ene.xis]

In theory, the render should be quicker using the precalcd vrmap & vrlmap

how s that?

[leotchest]

quicker because you already have the calcs done for the IrMap & LC. This should cut down the render time compared to when you are rendering from scratch without any saved maps

[ene.xis]

ahh...but i mean the all process is gonna be slower, if u count pre calculating GI and rendering in a 2nd moment...

[leotchest]

what has me worried is the fact that if i render a singel frame without using saved maps - it takes about 40 minutes to render. If i do it using my saved maps it takes about 160 minutes to render the same frame. I hae to use the saved IrrMap as its the only way to avoid flicker. I was wondering if maybe this was to do with the way I had saved the maps ? On that particular job i saved a seperate vrmap & vrlmap (& the vrlmap had glossies turned off)