more prepasses with lower settings??

[Bowcat]

Hi

I am about to render a high resolution image. I set irradiance map max and min rate to -5 and -3 so it can render faster, but the number of prepasses go up. Is this normal?

Thanks.

[flipside]

-5/-3 means -5,-4,-3 : 3 passes

www.vray.info lots of info there about this

interpolation for glossy materials also uses passes!

[Bowcat]

oh, ok. Thanks

[DaftPunk]

you could have -3 and -1 and it would be 3 passes, but, the numbers also correspond to SUBDIVISONS. You can have 3 passes at -18 and -16, but, it wouldnt look good at all.

[EricKlein]

-5/-3 means -5,-4,-3 : 3 passes

www.vray.info lots of info there about this

interpolation for glossy materials also uses passes!

Hi Flipside,

First post here- I'm pushing the learning curve pretty hard right now, and I'm really amazed with what's possible w/ vray...This forum has been an outstanding resource over the past few weeks as I try to get up to speed. I'm looking for a quick clarification here regarding prepass w/glossy interpolation.

I'm using glossy interp. in a still image rendered at 9000x4500. My workflow has been to use light cache/ Light cache, at around 1500 samples /.02/ screen prefilter w/ glossy/nearest 10.

I run out that pass w/ render final off, save it, switch to the saved map, then turn on Irr. map, and distribute the irr map pass.

Once that is saved, I switch to the saved file, and DR the entire scene.

My question is this (finaly): When the render starts, instead of going right into the final render it says "prepass 1 of 1"....This is because of the glossy interp. on the one material right??? Otherwise is should just start rendering, yes? Do I have to go all the way back to square 1, turn off interpolation, and re-run my bounces to get rid of it? Also, I should note that I'm making those bounce passes at 1/2 resolution, and then going full size for the final render.

Thanks,

Eric.

[flipside]

I usually don't use interp glossies as they don't look good in many cases. You need high settings for them, and then it becomes almost as slow as normal glossies. For animation there are not good either because they will differ from frame to frame.

So easiest way: don't use them.

What are your settings fort the interp glossies?

Do you have the 'use LC for glossy rays' turned on in your LC settings?

[flipside]

Also, I should note that I'm making those bounce passes at 1/2 resolution, and then going full size for the final render.

LC is not resolution dependant, so it doesn't matter at what res you calculate the LC.

For ir map you could simply leave res at your high values, and lower the min/max both by 1. That will give you the same map as rendering at half the resolution.

[EricKlein]

Also, I should note that I'm making those bounce passes at 1/2 resolution, and then going full size for the final render.

LC is not resolution dependant, so it doesn't matter at what res you calculate the LC.

For ir map you could simply leave res at your high values, and lower the min/max both by 1. That will give you the same map as rendering at half the resolution.

ahh, interesting..(lc is res independant) Looking throught the flythrough tut it seemed like idealy you don't want to see any real 'artifacts' or 'unresolved' looking areas in your final LC (with nearest on). Is this the case? Doesn't the solution get a bit smoother once you run the IRR Map? in other words, if I see a few unresolved places in my flythrough LC, should I lower the sample size until it's perfect, or let it ride?

[EricKlein]

I usually don't use interp glossies as they don't look good in many cases. You need high settings for them, and then it becomes almost as slow as normal glossies. For animation there are not good either because they will differ from frame to frame.

So easiest way: don't use them.

What are your settings fort the interp glossies?

Do you have the 'use LC for glossy rays' turned on in your LC settings?

I blew off the interp. glossies- saving that mystery for another non-stress project (if that day ever comes)

Yes, I do have LC for glossy rays checked. seems like a good idea, yes?

I've also ticked pre-filter @ 15.

e

[flipside]

In the end, LC is used for second bounces only, first bounce is calculated with IR map. During ir map calculation, the already known lc info is used to speed up IR map calculations.

Your lc result should look pretty good, but not perfect (otherwise there would be no need to use ir map at all if your lc is already perfect).

Read the parts about 'use lc for glossy rays' in the flytrough tut, it's pretty important (i never use it to avoid problems, and sometimes it will result in poor glossies).