Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: lacilaci on 2013-01-22, 08:50:14

Title: Next event estimation...
Post by: lacilaci on 2013-01-22, 08:50:14

Will this boost rendering when path tracing complex GI situations?

Title: Re: Next event estimation...
Post by: Ondra on 2013-01-22, 09:38:08

It already is

Title: Re: Next event estimation...
Post by: Sam75 on 2013-01-22, 14:47:10

Can you explain what is it ?

Title: Re: Next event estimation...
Post by: Ondra on 2013-01-22, 16:42:23

Quote from: Sam75 on 2013-01-22, 14:47:10

Can you explain what is it ?

It's just fancy name for shadow rays

Title: Re: Next event estimation...
Post by: lacilaci on 2013-01-22, 17:50:41

really? :D I though that it is some nice ultra pathtracing on steroids in VCM :D lol.... Anyways, seems to be similar to bi-dir speedwise...

Title: Re: Next event estimation...
Post by: Ondra on 2013-01-22, 18:54:41

Ah, you  mean you use it in VCM ;) No, that just sets the VCM renderer into mode equivalent to using PT+PT with max sample intensity 0 and PT samples and light multiplier = 1.

You can see the effect of turning next event estimation on/off by using PT+PT and switching direct light mode between MIS and BSDF only

Title: Re: Next event estimation...
Post by: Sam75 on 2013-01-22, 19:03:13

Keymaster, Bdir code is still broken in latest builds:

bidirrenderer.ccp(261)

Title: Re: Next event estimation...
Post by: Ondra on 2013-01-22, 19:30:11

yes, it will be probably eventually removed. Use VCM in bidir mode instead

Title: Re: Next event estimation...
Post by: Sam75 on 2013-01-22, 19:37:18

Ok it works with VCM as renderer, thanks.

Title: Re: Next event estimation...
Post by: lacilaci on 2013-01-23, 08:19:57

By the way... What is the difference between using VCM in Bi-Dir mode and standard Bi-Dir?

Title: Re: Next event estimation...
Post by: Ondra on 2013-01-23, 09:13:53

Quote from: lacilaci on 2013-01-23, 08:19:57

By the way... What is the difference between using VCM in Bi-Dir mode and standard Bi-Dir?

That VCM in bidir mode does not crash ;)

Title: Re: Next event estimation...
Post by: lacilaci on 2013-01-23, 09:18:08

lol :D I was more wondering why you chose to dump standard bidir and use VCM but okay, I understand if you don't want to tell ;)

Title: Re: Next event estimation...
Post by: Ondra on 2013-01-24, 01:01:26

trolling is an art ;).

but seriously, VCM is slightly slower, because it is harder to parallelize right. But since VCM is in a way a combination of ALL other algorithms used for unbiased rendering (except for metropolis ones), it is very easy to modify it to get these algorithms (bidir, progressive photon mapping, path tracing, light tracing). And since bidir is very complicated and demanding, it does not make sense to maintain a separate implementation. I'll just have to make the multithreading more efficient.