Glossy interpolation...how low can you go?

[Dman3d]

Ok, got an out of control animation. With IRMAP done its taking 1.5 hours
per frame. Now you guys know me I love fuzzy reflections, so ...
Without doing a zillion hours of test renders does anyone have a suggestion
or guidline for using glossy interpolation to get the render times down?

They dont need to be accurate just there and not too crappy.

Sorry if this is an elementary question but I am out of my mind right
now.

[GoncaloP]

can you show a image?

Gonçalo

[Dynedain]

I am in the exact same situation, compounded that the glossy reflections are causing light blotchy artifacts.

[Dman3d]

GoncaloP - an example would be either of the two living rooms posted
in the image upload area. Neither one uses interpolation - wondering
if I can get the time down significantly by turning them off.
Example:
http://www.chaoticdimension.com/foru...pic.php?t=3942


A recent test on anoter project resulted in some interesting numbers.
With IRMAP done it was taking something around 25-35 min a frame
the same file with reflections off took around 3 min a frame.
That got me to thinking heavily about interpolation and how I can use it
to get the times down, or any other techniques for getting decent
reflections in a faster time. The thing to me about glossy reflections
is they dont always need to be acurate just somewhat believable.
Too bad this not another option that says "just kind of create a reflection
of a color or intensity in this range when it is really fuzzy" -

So I was wondering if anyone had a rule of thumb that might save me some
testing time.

[GoncaloP]

The speculars, you can fake them with omni lights and for major reflections if not many you can try interpolations if you are not using bump maps, it can turns out nice and aa will be very fast.

Gonçalo

[Dman3d]

For the image above there are some bumps but the project in question
does not (for the most part.) Most of the blurry refleections are on objects
like wood on furniture (tables, chairs) and then major objects like tile
floor.

As for faking with an omni, can you provide an example?
and for interpolation settings for the case you suggest?

What AA method would you recommend for animation?
For the stills I make I dont worry too much about time budget, most
of the time as long as it renders overnight and looks good.
The animations are giving me a fit.

You guys know the drill. Customer orders stills, we give stills. Then they
want animations added on in some rediculous deadline. Trying to explain
all the gotcha's to anyone else is almost pointless, they just want the
pretty moving pictures.

[flipside]

There are options to seperate the reflection interpolation prepasses and GI prepasses. So I assume they somehow work together during GI calculation. I you already have your IR map saved, and then change the glossy reflection to interpolated ones, this could create problems with the saved IR map. Never tested it though but it just came into my mind.

There's no rule of thumb for what settings you should use... I'd suggest trying lower subdivs values for you glossy reflections first, before trying interpolation. It also depends a lot on the geometry. Flat areas could look great with interpolation, but curved objects usually look terrible... You'll need to use high quality settings for the interpolation and this can be also slow.

[Daniele]

But... If you save the IR map and then reuse it for animation, with interpolated reflections activated you always get more render passes for each frame (and they always take too much time...). So I think that also with an already saved IR map you should be able to switch from interpolated/non iterpolated reflections, and change the prepass too.
Or not?

[egz]

But... If you save the IR map and then reuse it for animation, with interpolated reflections activated you always get more render passes for each frame (and they always take too much time...). So I think that also with an already saved IR map you should be able to switch from interpolated/non iterpolated reflections, and change the prepass too.
Or not?

Not. Irradiance maps and interpolated reflections have little to do with each other. Reflection interpolations are view dependent and can't be stored in the irradiance map, but always have to be calculated for each frame.

[cocolas]

The speculars, you can fake them with omni lights and for major reflections if not many you can try interpolations if you are not using bump maps, it can turns out nice and aa will be very fast.

Gonçalo

yeah, goncalo, can you give an example of speculars faked w/ omnis....? as well as interpolation settings....


thanks in advance,

paul.